JP2008208899A - Blind rivet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blind rivet which can fully expand circumferential each portion of preliminarily set longitudinal portion of tube tip side of rivet body at the state of uniformity, and fasten each fastened member firmly and stably. <P>SOLUTION: The blind rivet is characterized in that it comprises a rivet body 7 and mandrel 11, in that in the rivet body 7, a flange 6 is circumferentially arranged in the base end of tube 3 with a penetrated insertion hole 2, in that the tip side of the tube 3, a thin wall tube portion 15 is formed by enlarging an internal diameter of the insertion hole 2, and a step portion 20 is arranged in the inner end of its inner peripheral surface 17, in that the inner side portion of head portion 10 of the mandrel 11 has a diameter contraction insertion portion 39 inserted into the tip portion of the insertion hole 2, and in that by pulling a grip axle 49 of the mandrel axle 9 in such a manner of gripping, the head portion 10 can expand the thin-walled tube portion 15 by keeping the circumferential each portion at the state of uniformity. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to blind rivets. More specifically, when the members to be fastened are fastened together, the mandrel is pulled with a required pulling force, so that each part in the circumferential direction of the preset length portion on the tip side of the cylindrical portion of the rivet body is expanded uniformly. And then the mandrel can be broken, whereby the to-be-fastened members can be firmly and stably fastened with respect to the blind rivet.

  As conventional blind rivets, those disclosed in Japanese Patent Laid-Open No. 11-13723, those disclosed in Japanese Patent Laid-Open No. 8-159127, and those disclosed in Japanese Patent Laid-Open No. 2005-226807 have been proposed.

  As shown in FIGS. 22 (A) and 22 (B), the blind rivet a1 disclosed in the Japanese Patent Application Laid-Open No. 11-13723 is fixed so that the flange c1 of the hollow rivet body b1 is pressed against the fastened member d. By pulling e1, as shown in FIG. 22 (B), the front portion g1 of the cylindrical portion f1 of the rivet body b1 can be expanded in a folded state to form an expanded diameter portion h, and the mandrel e1 It is configured to be broken at the broken portion j1 at the time of losing the tensile force, so that both the fastened members d and d can be fastened between the expanded diameter portion h and the flange c1. It was made to.

  The blind rivet a2 disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 8-159127 is fixed so that the flange c2 of the hollow rivet body b2 is pressed against the fastened member d, as shown in FIGS. By pulling the mandrel e2, the front side portion g2 of the cylindrical portion f2 of the rivet body b2 can be expanded outwardly, and when the mandrel e2 loses the tensile force, it is broken at the broken portion j2. Thus, both the fastened members d and d can be fastened between the enlarged diameter portion k and the flange c2.

  In addition, the blind rivet a3 disclosed in the Japanese Patent Application Laid-Open No. 2005-226807 is fixed so that the flange c3 of the hollow rivet body b3 is pressed against the member to be fastened d, as shown in FIGS. By pulling the mandrel e3, the blade n of the mandrel head m can incline the tip part g3 of the cylinder part f3 of the rivet body b3 while expanding the diameter of the front part g3 of the cylinder part f3. When e3 loses the tensile force, it is configured to be broken at the broken portion j3, whereby, as shown in FIG. 24 (B), the fastened portion between the enlarged diameter portion p and the flange c3. The members d and d can be fastened together.

  In any of the blind rivets having such a configuration, by pulling on the mandrel e1, the front side portion of the cylindrical portion f3 of the hollow rivet body b1 is expanded or expanded so that the expanded diameter portion f and the expanded diameter portions k, p are formed. It can be formed, and the mandrel e1 is further pulled, so that the mandrel is broken at the break when it loses the pulling force.

  However, each blind rivet is formed so that the outer diameters of the cylindrical portions f1, f2, and f3 of the rivet main body are substantially equal and the inner diameter is also substantially equal. Therefore, the front side portion g1, of the cylindrical portions f1, f2, and f3 is formed. The thicknesses of g2 and g3 were large. Therefore, the expansion and expansion of the cylindrical portions f1, f2, and f3 due to the pulling of the mandrels e1, e2, and e3 are difficult to be performed uniformly in each circumferential portion of the cylindrical portion, and the half-expanded state and expansion are halfway. In some cases, the mandrel was broken in the diameter state. In this case, since a necessary fastening force can be obtained only at a part that is expanded as required, there is a problem that the fastening force between the members to be fastened by the blind rivet becomes incomplete.

Japanese Patent Laid-Open No. 11-13723 JP-A-8-159127 JP 2005-226807 A

  The present invention has been developed in view of the above-mentioned conventional problems, and when the members to be fastened are fastened to each other, the mandrel is pulled with a required pulling force, so that the leading end side of the cylindrical portion of the rivet body is set in advance. In the blind rivet, each circumferential part of the length portion can be expanded in a uniform state, and then the mandrel can be broken, whereby the members to be fastened can be fastened firmly and stably. Providing is an issue.

In order to solve the above problems, the present invention employs the following means.
That is, the blind rivet according to the present invention has a rivet body provided with a flange at the base end of a cylindrical portion having an insertion hole penetrating in the axial direction, and a head at the base end of a mandrel shaft portion inserted through the cylindrical portion. And a mandrel provided with a break portion as a thin shaft portion at an intermediate portion of the mandrel shaft portion, and the inner end portion of the insertion hole increases the inner diameter of the insertion hole. Thus, a thin cylindrical portion is formed, and a stepped portion projecting inward of the insertion hole is provided at the inner end of the inner peripheral surface of the thin cylindrical portion. The inner portion of the head portion of the mandrel is a reduced diameter fitting portion that is fitted into the distal end portion of the insertion hole, and the grip shaft portion that protrudes from the flange of the mandrel shaft portion is gripped and pulled. The head is configured to be able to expand the thin cylindrical portion outward, and the expansion is completed when an inner end of the reduced diameter fitting portion abuts on the stepped portion. Then, by further pulling the grip shaft portion, the mandrel shaft portion is broken at the break portion.

  In the blind rivet, the inner portion is fitted to the distal end portion of the insertion hole at the inner end of a conical portion having a concave curved outer peripheral surface that is concavely curved and gradually decreases in diameter toward the distal end side of the mandrel shaft portion. It is good to comprise as a thing with the reduced diameter insertion part which can be put.

  In the blind rivet, a recess may be provided on the outer surface of the tube portion of the rivet body between the thin tube portion and the flange by drawing by cold forging from the outer surface side.

  In the blind rivet, the outer diameter of the head is preferably formed to be substantially the same as the outer diameter of the thin cylindrical portion.

  In the blind rivet, the inner edge portion of the distal end of the thin tube portion of the rivet body may be formed as a conical circumferential surface inclined inward and toward the proximal end of the tube portion.

The present invention has the following excellent effects.
(1) The present invention provides a thin-walled cylindrical portion at the distal end side of the cylindrical portion of the rivet body, and a reduced-diameter insertion portion that can be fitted into the distal end portion of the insertion hole of the cylindrical portion, and the thin-walled portion. In order to adopt a configuration in which a step portion is provided at the back end of the inner peripheral surface of the cylindrical portion, each circumferential portion of the preset length portion on the distal end side of the cylindrical portion of the rivet body is outward in a uniform state. The mandrel shaft can be broken thereafter. For this reason, when using the blind rivet of the present invention, the members to be fastened can be fastened firmly and stably with a required fastening force. This will be described more specifically below.

  When using the blind rivet according to the present invention, the reduced diameter insertion portion of the mandrel head can move in the thin cylindrical portion toward the stepped portion, and accordingly, the thin cylindrical portion is gradually outward. Although it can be expanded, since the thickness of the thin tube portion is thin, the expansion can be easily performed. And since the said reduced diameter insertion part is inserted in the front-end | tip part of the said insertion hole, as this reduced diameter insertion part moves sequentially toward the said level | step-difference part in the said thin cylinder part, of this thin cylinder part Each part in the circumferential direction can be expanded outward in a uniform state. Then, the expansion can be continued until the inner end of the reduced diameter insertion portion comes into contact with the stepped portion, and the expansion can be completed by the contact, resulting in variations in the expansion as in the prior art. Without making it, the whole thin-walled cylindrical portion can be deformed to a required expanded state. Thereafter, by further pulling the grip shaft of the mandrel while the inner end of the reduced diameter fitting portion is in contact with the stepped portion, the head of the mandrel can be fixed to the rivet body against this pulling. Therefore, the mandrel shaft portion can be broken at the breaking portion. For this reason, when using the blind rivet of the present invention, the members to be fastened can be fastened firmly and stably with a required fastening force.

(2) Since the present invention adopts a configuration in which the reduced diameter insertion portion of the head portion is fitted into the distal end portion of the insertion hole of the cylindrical portion, as in the conventional blind rivet as shown in FIG. When the thickness of the head in the length direction of the mandrel shaft portion is the same as when the entire inner surface of the portion is in contact with the tip surface of the tube portion, the head from the tip of the tube portion is The protrusion amount can be reduced by the thickness of the reduced diameter insertion portion. Therefore, the length of the fastening hole provided when fastening the members to be fastened can be set smaller, and therefore the blind rivet according to the present invention can be applied to a member to be fastened having a small member thickness.

  In particular, when the inner edge portion of the distal end of the thin-walled cylindrical portion of the rivet body is formed as a conical circumferential surface inclined inward and toward the proximal end, the distal end of the thin-walled tubular portion is As apparent from the comparison between the case shown in FIG. 12A having a conical peripheral surface and the case shown in FIG. 12B where the tip does not have the conical peripheral surface, The one having a peripheral surface can reduce the amount of protrusion of the head from the tip of the cylinder part because the head can be more fitted into the tip part of the insertion hole of the cylinder part. Therefore, the blind rivet can be applied to a fastened member having a thinner member thickness.

(3) In particular, when a hollow portion is formed by drawing by cold heading from the outer surface side between the thin tube portion and the flange on the outer surface of the tube portion of the rivet main body, processing associated with the drawing Since the strength of the cylindrical portion can be improved by curing, it is possible to more reliably prevent the intermediate portion from bulging outward and deforming when the thin cylindrical portion is expanded. It can be surely expanded as required.

  1 to 3, a blind rivet 1 according to the present invention is inserted into a rivet body 7 in which a flange 6 is provided at a proximal end 5 of a cylindrical portion 3 having an insertion hole 2 penetrating in the axial direction, and the insertion hole 2. And a mandrel 11 having a head 10 provided at the base end of the mandrel shaft 9. This will be specifically described below.

  As shown in FIGS. 1 to 3 and FIG. 4A, the rivet body 7 is formed by cold forging using a metal, for example, an aluminum alloy in this embodiment, and penetrates in the axial direction. The flange 6 having a circular plate shape, for example, is provided around the outer peripheral surface of the base end 5 of the cylindrical tube portion 3 having the hole 2. And the part at the side of the front-end | tip 13 of this cylinder part 3 is made into the thin cylinder part 15 by enlarging the internal diameter of the said insertion hole 2, and the front-end | tip 16 of this thin cylinder part 15 and its internal peripheral surface 17 exhibit a right angle. . A stepped portion 20 projecting inwardly (in the radial direction) of the insertion hole 2 is formed at the inner end 17 of the inner peripheral surface 17 of the thin cylindrical portion 15 (the end on the bottom side inside the thin cylindrical portion 15). Are provided so as to be continuous in the circumferential direction. In the present embodiment, the stepped portion 20 is formed as a right-angled stepped surface 20a that is perpendicular to the inner peripheral surface 17 of the thin-walled cylindrical portion 15.

  In this embodiment, the hollow portion 23 is formed on the outer surface of the cylindrical portion 3 by drawing by cold heading from the outer surface side between the thin cylindrical portion 15 and the flange 6 (intermediate portion 22). A plurality of, for example, four, are provided in the circumferential direction via the interrupted portions 18. In the recess 23, the strength is improved by work hardening accompanying drawing. In addition, since the strength of the hollow portion 23 is improved in this way, the mandrel shaft portion 9 is broken at the break portion 40 described later at the end portion 24 (FIG. 4) on the flange 6 side of the hollow portion 23. In order to facilitate the later removal of a grip shaft portion 49, which will be described later, the flange portion 6 is prevented from projecting toward the flange 6 side with respect to a distal end 51 (FIG. 4D) of a bulging engagement portion 47 which will be described later.

  If the dimensions of each part of the rivet body 7 having such a configuration are illustrated with reference to FIG. 5, the length L1 of the cylindrical portion 3 is 11 mm, the outer diameter L2 is 4 mm, and the inner diameter L3 of the portion 25 excluding the thin cylindrical portion 15. Is 2.5 mm, the inner diameter L4 of the thin-walled cylindrical portion 15 is 3 mm, the width of the stepped portion 20 viewed in the radial direction of the cylindrical portion (the width of the right-angled stepped surface 20a) L5 is 0.25 mm, The thickness L6 is 0.5 mm, the distance L7 between the opposing recesses 23 and 23 is 3.8 mm, and the length L8 of the recess 23 in the tube length direction is 4.6 mm. The rivet body 7 having an outer diameter L2 of 4 mm is one of general products. In this case, the width L5 of the stepped portion 20 viewed in the radial direction of the cylindrical portion is set in a range of 0.15 to 0.55. The thickness L6 of the thin-walled cylinder portion 15 can be set to 0.7 to 0.3.

  As shown in FIGS. 1 and 3 to 4, the mandrel 11 is formed by cold forging using a metal, for example, a hard steel wire in this embodiment, and is inserted into the cylindrical portion 3, for example, with a circular cross section. The head portion 10 is formed at a proximal end 27 of a mandrel shaft portion 9 having an elongated rod shape and a tapered distal end 26. The head portion 10 is formed to have the same diameter as the outer diameter of the thin cylindrical portion 15. The head 10 has an outer portion 30 having a flat cylindrical shape and an inner portion 31 having a smaller diameter than that of the outer portion 30, and the inner portion 31 gradually becomes smaller in diameter toward the tip 26 side. A reduced-diameter fitting portion that is fitted into the distal end portion 35 of the insertion hole 2 (the distal end portion 37 of the inside 36 of the thin-walled cylindrical portion 15) at the inner end of the conical portion 33 having the concave curved outer peripheral surface 32 that is concavely curved. 39 is provided. Further, a breakage portion 40 is provided in the intermediate portion 38 of the mandrel shaft portion 9 for facilitating breakage. In the present embodiment, the breaking portion 40 is a narrow shaft portion between the opposing concave portions 42 and 42 formed by constricting the opposing surface of the mandrel shaft portion 9 so as to be recessed in a V shape by cold heading. 43 (FIG. 4A), even when the mandrel shaft portion 9 is broken, the fracture surface 45 is accommodated in the tube portion 3 of the rivet body 7 as shown in FIG. It is provided as follows.

  Further, in this embodiment, as shown in FIGS. 3 and 4A, the intermediate portion 38 of the mandrel shaft portion 9 is pressed on the opposite side at a portion closer to the tip of the shaft portion than the fracture portion 40. The flat surfaces 46 and 46 are formed in an opposing state, and at the same time, bulging engagement portions 47 and 47 that slightly bulge in a direction orthogonal to the pressing direction are formed. The front side of the mandrel shaft portion 9 protrudes long from the flange 6, and the protruding portion is a grip shaft portion 49 that is gripped by a gripping portion of a drawing tool (not shown).

  FIGS. 1 and 2 and FIG. 4 (A) show a blind rivet 1 in which the rivet body 7 and the mandrel 11 are integrated, and the cylinder portion 3 of the rivet body 7 is opposite to the flange 6. The mandrel shaft portion 9 is inserted from the distal end side 50 (FIG. 3), and the reduced diameter fitting portion 39 of the head 10 is fitted into the distal end portion 35 of the insertion hole 2. In this state, as shown in FIG. 4 (D), the tips 51, 51 of the bulging engagement portions 47, 47 are in pressure contact with the inner peripheral surface 44 of the insertion hole 2 of the cylindrical portion 3, and this pressure contact is caused. There is no risk that the mandrel 11 will inadvertently fall off the rivet body 7 due to the accompanying frictional action.

  FIGS. 6 to 10 show that the blind rivet 1 is used, for example, to form a channel-shaped first member to be fastened 52 and a second member to be covered with a foam material 57 between the aluminum plates 53 and 55. An operation process for fastening the fastening members 56 in contact with each other will be described.

  First, in a state where the first and second fastened members 52 and 56 are in contact with each other, the aluminum plate 53 outside the second fastened member 56 from the outer surface 59 side of the first fastened member 52. It is set as the state where the bottomed fastening hole 60 was provided. The diameter of the fastening hole 60 is set to such an extent that the cylindrical portion 3 of the rivet body 7 can be inserted.

  Thereafter, as shown in FIG. 7, the cylindrical portion 3 of the rivet body 7 is inserted into the fastening hole 60 together with the head portion 10, and the flange 6 of the rivet body 7 is inserted into the outer surface 59 of the first fastened member 52. In a contact state. Thereafter, the grip shaft portion 49 of the mandrel shaft portion 9 is gripped by a drawing tool (not shown), and the mandrel shaft portion 9 is separated from the flange 6 while pressing the flange 6 against the outer surface 59 of the first fastened member 52. Pull in the direction indicated by the arrows in FIGS.

  As a result, the reduced diameter fitting portion 39 of the head portion 10 moves toward the stepped portion 20 in the thin cylindrical portion 15. With this movement, the inner edge 61 of the tip 16 of the thin-walled cylinder 15 and the inner peripheral surface 17 of the thin-walled cylinder 15 are guided by the concave curved outer peripheral surface 32 and gradually and smoothly as shown in FIG. Although it is expanded outward, the expansion is easily performed because the thin cylindrical portion 15 is thin. The reduced diameter fitting portion 39 is fitted into the distal end portion 35 of the insertion hole 2, and the reduced diameter fitting portion 39 sequentially moves inside the thin cylindrical portion 15 toward the stepped portion 20. Therefore, the thin cylindrical portion 15 is expanded so that each portion in the circumferential direction is smoothly curled outward in a uniform state. Then, as shown in FIG. 9, the expansion is continued until the inner end 62 of the reduced diameter fitting portion 39 (the inner end 63 of the head portion 10) contacts the stepped portion 20 (the right-angle stepped surface 20a). Since the expansion can be completed by abutting, the entire thin cylindrical portion 15 is deformed to a required expanded state without causing variation in the expansion as in the conventional case, and the expansion deforming portion 65 Can be formed.

  In the present embodiment, the expanded deformable portion 65 is in pressure contact with the peripheral portion 66 of the hole of the inner aluminum plate 55 in a state where the foam material 57 around the fastening hole 60 is broken. As a result, the first and second members to be fastened 52 and 56 are held by the expansion deforming portion 65 and the flange 6, and the first and second members to be fastened can have a required fastening force. It will be fastened firmly and in a stable state.

  In the present embodiment, as described above, a configuration is adopted in which the depression 3 is formed on the outer surface of the intermediate portion 22 in the length direction of the cylindrical portion 3 by drawing by cold forging from the outer surface side. Therefore, the strength of the recess 23 is improved by work hardening accompanying the drawing. For this reason, when the thin cylindrical portion 15 is expanded as described above, the intermediate portion 22 of the cylindrical portion 3 can be more reliably prevented from bulging outward and deformed, thereby making the thin cylindrical portion 15 necessary. It can be surely expanded.

  Then, even after the inner end 62 of the reduced diameter fitting portion 39 comes into contact with the stepped portion 20 as shown in FIG. 9, when the grip shaft portion 49 is pulled away from the flange 6 by the pulling tool, Since the head portion 10 is fixed to the rivet body 7 with respect to this pull, the pulling force becomes a force that deforms the breaking portion (thin shaft portion) 40, and the mandrel shaft portion 9 breaks at the breaking portion 40. Will be. The fracture surface 45 is accommodated in the cylindrical portion 3 as shown in FIG.

  The present invention is by no means limited to those shown in the above-described embodiments, and it goes without saying that various design changes can be made within the scope of the claims. One example is as follows.

(1) FIG. 11 shows another embodiment of the blind rivet 1 according to the present invention.
In the blind rivet 1 shown in FIGS. 11A and 11B, the inner edge portion 61 of the distal end 16 of the thin-walled cylindrical portion 15 of the rivet body 7 is inclined inward and toward the proximal end 5. It is formed as a conical peripheral surface 67. The conical circumferential surface 67 may be a circumferential surface having an arcuate cross section as shown in FIG.

  With this configuration, when the mandrel shaft portion 9 is inserted into the rivet body 7, the conical circumferential surface 67 is inserted into the distal end portion 35 of the insertion hole 2 when the reduced diameter insertion portion 39 is inserted. Therefore, this insertion can be performed smoothly.

  Further, in this configuration, the tip 16 of the thin-walled cylindrical portion 15 has the conical circumferential surface 67 as shown in FIG. 12A, and the tip 16 has the conical circumferential surface 67. As is clear from the comparison with the case shown in FIG. 12B, the one having the conical circumferential surface 67 places the head 10 in the distal end portion 35 of the insertion hole 2 of the cylindrical portion 3. It is possible to achieve a more fitted state. For this reason, the one having the conical peripheral surface 67 can further reduce the amount of protrusion of the head from the tip 13 of the cylindrical portion 3, and thus the blind rivet 1 has a smaller member thickness. This can also be applied to a fastened member.

  In the blind rivet 1 shown in FIGS. 13A and 13B, the inner edge 61 of the distal end 16 of the thin-walled cylindrical portion 15 of the rivet body 7 is inclined inward and toward the base end 5. The conical peripheral surface 67 is formed, and the inner portion 31 of the head portion 10 of the mandrel 11 is configured to have a conical peripheral surface 70 that can abut against the conical peripheral surface 67. The conical peripheral surfaces 67 and 70 come into contact with each other, so that the reduced diameter insertion portion 39 of the head 10 is fitted into the distal end portion 35 of the insertion hole 2.

  In the blind rivet 1 configured as described above, since the both conical circumferential surfaces 69 and 70 are in contact with each other as described above, the grip shaft portion protruding from the flange 6 of the mandrel shaft portion 9 is used. 49. As the head 10 moves toward the stepped portion 20 by gripping and pulling 49, the head 10 is caused to move toward the stepped portion 20 by the directing action of the conical peripheral surfaces 67 and 70. 15 can be expanded to the outside without difficulty. Then, when the inner end 62 of the reduced diameter fitting portion 39 abuts on the stepped portion 20, the outward expansion of the thin cylindrical portion 15 can be completed. By further pulling the grip shaft portion 49, the mandrel shaft portion 9 can be broken at the breaking portion 40 in the same manner as described above. The conical peripheral surfaces 67 and 70 may be arcuate surfaces as shown in FIG.

  In the case of such a configuration, as shown in FIGS. 14 (A), 14 (B), 15 (A) and 15 (B), at the inner end of the conical circumferential surface 70, the tip portion 35 of the insertion hole 2 is provided. Furthermore, you may provide the insertion part 71 inserted. In this case, the inner portion 31 and the insertion portion 71 constitute a reduced diameter insertion portion 39.

  Even when the head 10 has the conical circumferential surface 70 as described above, for example, the case shown in FIG. 14A will be described. The distal end 16 of the thin-walled cylindrical portion 15 is the conical circumferential surface. As shown in FIG. 16 (A) having 67 and the case shown in FIG. 16 (B) in which the tip 16 does not have the conical circumferential surface 67, the conical circumferential surface. The one having 67 can make the head 10 more fitted in the distal end portion 35 of the insertion hole 2 of the cylindrical portion 3. For this reason, the one having the conical circumferential surface 67 can further reduce the amount of protrusion of the head from the tip 13 of the cylindrical portion 3, and thus the blind rivet 1 has a smaller member thickness. This can also be applied to a fastened member.

(2) Although the step 20 is formed as a right-angle step as described above, the mandrel shaft portion 9 can be easily broken. In FIG. An obtuse angle (for example, about 100 to 110 degrees) is formed with the inner peripheral surface 17 continuously provided in the circumferential direction at the rear end (end on the bottom side inside the thin-walled cylindrical portion 15) 19 of the peripheral surface 17. It is formed as an inclined surface (an inclined surface inclined toward the base end 5 side of the cylindrical portion 3) 20b.

  Even when the stepped portion 20 is configured in this manner, by pulling the grip shaft portion 49, the tip 62 of the reduced diameter fitting portion 39 comes into contact with the stepped portion 20 as shown in FIG. The outward expansion of the thin cylindrical portion 15 can be completed. Then, by further pulling the protruding grip shaft portion 49, the mandrel shaft portion 9 can be broken at the breaking portion 40 in the same manner as described above. As a result, the first and second fastened members 52 and 56 are held by the expanding deformable portion 65 and the flange 6, and the first and second fastened members are firmly connected to each other with a required fastening force. And it is fastened in a stable state.

(3) In the blind rivet 1 according to the present invention, the head portion 10 has a blade portion capable of cutting the thin tube portion 15 from the tip toward the flange 6 as the mandrel shaft portion 9 is pulled. May be configured.

(4) The fracture portion 40 may be formed by denting the peripheral surface of the mandrel shaft portion 9 by cold heading at an angular pitch of 90 degrees, for example. In short, what is necessary is just to comprise as a thin-axis part formed by providing a recessed part in this surrounding surface.

(5) FIG. 19 shows another aspect of the flange 6 provided at the base end 5 of the cylindrical portion 3 of the rivet body 7 constituting the blind rivet 1 according to the present invention. Projected only on the side. The flange 6 may have other configurations as long as the first and second fastened members 52 and 56 can be clamped between the flange 6 and the expanding deformable portion 65 to fasten both.

(6) As long as the hollow portion 23 can more reliably prevent the intermediate portion 22 of the cylindrical portion 3 from bulging outward and deforming when the thin-walled cylindrical portion 15 is expanded, the intermediate portion 22 In addition, for example, as described above, the independent depressions 23 are arranged with a necessary interval in the circumferential direction, and as shown in FIG. As shown in FIG. 21, it may be provided in an annular shape that is continuous in the circumferential direction.

It is a partial cross section front view which shows the blind rivet which concerns on this invention. FIG. FIG. It is the partial front view which cut the rivet main part. It is sectional drawing which shows a rivet main body. It is sectional drawing which shows the state which to-be-fastened members mutually contact | abutted. It is sectional drawing which shows the state which inserted the rivet main body of the blind rivet in the fastening hole provided in the to-be-fastened member. It is sectional drawing which shows the state which pulled the mandrel slightly and the thin-walled cylinder part was expanded. It is sectional drawing which shows the state which the inner end of the head of a mandrel contact | abutted to the level | step-difference part of a rivet main body, and the thin-walled cylinder part expanded. It is sectional drawing which shows the state which fractured | ruptured the mandrel in the fracture | rupture part. It is sectional drawing which shows the blind rivet which provides the rivet main body in which the inner edge part of the front-end | tip of a rivet main body was formed as a conical surrounding surface. It is a comparison figure of the amount of head protrusions when a tip of a rivet body has a conical peripheral surface and when it does not. It is sectional drawing which shows the other Example of the blind rivet which provides the rivet main body in which the inner edge part of the front-end | tip of a rivet main body was formed as a conical surrounding surface. It is a fragmentary sectional view which shows the other Example of the blind rivet by which the reduced diameter insertion part was comprised by providing the insertion part. It is sectional drawing which shows the other Example of the blind rivet by which the reduced diameter insertion part was comprised by providing the insertion part. It is a comparison figure of the amount of head protrusions when a tip of a rivet body has a conical peripheral surface and when it does not. It is a fragmentary sectional view which shows the blind rivet which provides the rivet main body in which the level | step-difference part was formed as an inclined surface. It is sectional drawing which shows the state which to-be-fastened members were fastened by the blind rivet. It is a perspective view which shows the other aspect of the flange of a rivet main body. It is a perspective view which shows the other aspect of a hollow part. It is a perspective view which shows the other aspect of a hollow part. It is sectional drawing which shows the conventional blind rivet with the use condition. It is sectional drawing which shows the other aspect of the conventional blind rivet with the use condition. It is sectional drawing which shows the other aspect of the conventional blind rivet with the use condition.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Blind rivet 2 Insertion hole 3 Cylindrical part 6 Flange 7 Rivet main body 9 Mandrel shaft part 10 Head 11 Mandrel 15 Thin-walled cylindrical part 16 Thin-walled cylindrical part 17 Inner peripheral surface of thin-walled cylindrical part 19 Inner peripheral surface inner end 20 Step Part 22 Intermediate part of the cylinder part 23 Reduced diameter part 30 Outer part of the head part 31 Inner part of the head part 32 Concave curved outer peripheral surface 33 Conical part 35 Tip part of the insertion hole 36 Inside of the thin-walled cylinder part 39 Reduced diameter insertion part 40 Break Part 43 Thin part 45 Broken surface 46 Flat surface 47 Swelling engagement part 49 Grip shaft part 51 Tip of swelling engagement part 52 First fastened member 57 Second fastened member 60 Fastening hole 61 Tip of thin part Inner edge portion 62 Inner end of reduced diameter insertion portion 63 Inner end of head portion 65 Widening deformation portion 69 Conical circumferential surface 70 Conical circumferential surface

Claims (5)

  A rivet body provided with a flange at the proximal end of a cylindrical portion having an insertion hole penetrating in the axial direction, and a head portion is provided at the proximal end of the mandrel shaft portion inserted through the cylindrical portion, and the mandrel shaft portion A mandrel provided with a break portion as a thin shaft portion in an intermediate portion, and the tip side portion of the tube portion is formed into a thin tube portion by increasing the inner diameter of the insertion hole. A stepped portion protruding inward of the insertion hole is provided at the inner end of the inner peripheral surface of the cylindrical portion, and an inner portion of the head portion of the mandrel is provided at a tip portion of the insertion hole. A reduced-diameter fitting portion to be fitted is provided, and the head portion can expand the thin cylindrical portion outward by gripping and pulling the grip shaft portion protruding from the flange of the mandrel shaft portion. Of the reduced diameter fitting portion The expansion is completed by abutting against the step portion, and then the mandrel shaft portion is broken at the break portion by further pulling the grip shaft portion. rivet.   The inner portion has a reduced-diameter fit that is fitted into the distal end portion of the insertion hole at the inner end of the conical portion having a concave curved outer peripheral surface that is concavely curved and gradually decreases in diameter toward the distal end side of the mandrel shaft portion. The blind rivet according to claim 1, wherein a portion is provided.   2. A hollow portion is provided on the outer surface of the tubular portion of the rivet body between the thin tubular portion and the flange by drawing by cold forging from the outer surface side. Blind rivets.   The blind rivet according to claim 1 or 2, wherein an outer diameter of the head is formed to be substantially the same as an outer diameter of the thin-walled cylindrical portion.   The inner edge part of the front-end | tip of the said thin cylinder part of the said rivet main body is formed as a cone-shaped surrounding surface which inclines toward the inner end and toward the base end of the said cylinder part or, 2. Blind rivet according to item 2.

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