JPS61171910A - Blind rivet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention Field of Industrial Use The present invention relates to a blind rivet that can fasten a plurality of plate parts from one direction.Prior art A blind rivet has a hollow rivet body and a rivet inserted into the rivet body. Insert the mandrel head into the mounting hole of the member to be mounted (for example, a plate) until the flange of the rivet body comes into contact with the flange of the rivet body, and then use a tool to strongly pull the mandrel shaft that protrudes from the flange. The mandrel shaft breaks from its small diameter part, and the enlarged head of the mandrel expands and buckles the shaft of the rivet body, and the buckled part and the flange connect the attached members to each other. I am told to do so. This blind rivet is convenient because the fastening operation can be performed from one direction.

Problems to be Solved by the Invention However, since the mandrel head after breakage remains unfixed within the rivet body shaft, it generates abnormal noise due to vibrations, etc., and it is difficult to install the rivet in a place where such noise is disliked. In addition, the buckling start position of the rivet body shaft is
This is the position where the mandrel head makes contact, and buckling started from this part.If the member to be attached is made of a material with low rigidity such as plastic, if the mandrel shaft is pulled hard enough to break, the mandrel head will buckle. The shaft of the rivet body expands and moves to the vicinity of the flange, sometimes penetrating the mounting hole of the member to be mounted. These situations will be explained using FIGS. 1 and 2. In Fig. 1, when fastening the plate 1 to the plate 2, insert the blind rivet 3 into the mounting hole 4K of both plates as shown in (A), and pull the mandrel shaft 5 downward as shown in (B). The mandrel head 6 begins to expand and buckle the rivet body shaft 7, and at the position (C), the shaft 7 and flange 8 close the plate l.
As the mandrel shaft 5 is fastened to the plate 2, the mandrel shaft 5 begins to break, and after the breakage (0), the mandrel neck 6 is not fixed within the shaft 7 and makes a rattling sound, as shown in (El)K. You will have to move around.

Furthermore, as shown in Fig. 2, when the members to be attached are plastic plates 1# and 2I, the first
Same as the figure, but in step (0), plates II and 2I
Because of the insufficient hardness, the rivet main body shaft 70 does not stop buckling, the mandrel shaft 5 does not break, and the head 6 continues to move until it reaches the 7th rung 80. After that, the mandrel shaft breaks due to the tensile force applied to the mandrel shaft 5, but as shown in FIG. 2′
In some cases, the bolts were forced to pass through the buckled portion, damaging the connection between the two plates.

Furthermore, as shown in (E)K in Figure 1, when one plate is fastened, the diameter of the mounting hole 4 in the plate l on the side that contacts the flange 8 is larger than the diameter of the rivet body shaft l. , this rounding caused a gap between KN and the plate 1 to move in the direction of the arrow 9 with respect to the plate 2, which was not a desirable method.

Therefore, an object of the present invention is to prevent the mandrel neck from moving within the rivet body shaft after fastening, to be able to properly fasten even soft materials, and to prevent the attached members from moving relative to each other. To provide a blind rivet that can be fastened. Means for Solving the Problems In order to achieve the above object, the blind rivet according to the present invention is provided in such a manner that the broken small diameter part of the mandrel shaft is located in the lower part separated from the mandrel head. A second small diameter portion is formed between the broken small diameter portion of the mandrel and the mandrel head. Further, the shaft portion of the rivet body is formed such that the outside diameter of the shaft portion is rounded at a position other than the fracture small diameter portion of the mandrel.

As a result, the diameter-reduced portion is constricted inward when the mandrel shaft is pulled.

Effect of the Invention Accordingly, a reduced diameter portion is formed at a position other than the small diameter portion of the mandrel when the rivet is broken, so that the shaft portion of the rivet main body is constricted inwardly. Rather than holding the mandrel shaft, it is fixed in the rivet body together with the mandrel head, so it does not move even when shaken or squeezed, eliminating the generation of abnormal noises. Also, when the %ff mandrel shaft is pulled, an inward K constriction occurs before the body shaft expands or buckles, so the mandrel head does not advance beyond this constriction, and the attached Even if the member is a soft material, it will not pass through the mounting hole.Furthermore, since buckling occurs from the inward constriction, that is, the reduced diameter part of the rivet body shaft, select the benevolence of the reduced diameter part. The rivet body shaft can be buckled in the mounting hole of the member to be attached by the K, and the member to be attached can be fastened together so that they do not move relative to each other by the recess K.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. 3 to 6, a blind rivet 1G (FIG. 6) according to an embodiment of the present invention has a mandrel 11 shown in FIG. 3 and a hollow rivet body 12 shown in FIG. It is also possible to combine them as shown, and to process the rivet body 12 as shown in FIG.

The mandrel 11 has a cylindrical shaft portion 14 that is longer than the rivet body 12 and has an outer diameter that can be inserted into the hollow hole 13 of the rivet body 12, and an enlarged head 15 formed at one end of the shaft portion 14.
It is nail-shaped as a whole, consisting of. Although not shown, it is preferable that the lower end of the incline opposite to the head tS be tapered, thereby facilitating insertion into a tensioning tool (not shown). The shaft portion 14 has a small diameter portion 1 at a position spaced apart from the lower surface of the head 15 for breakage of the mandrel shaft portion.
6 is formed, and this broken small diameter portion 16 and the head 1
A second small diameter part 17 is formed between the rupture part 5 and the second small diameter part 17. The diameter of this second small diameter part 17 is made larger than the fracture small diameter part 16, so that the mandrel is not broken at this part. . These small diameter parts including the broken small diameter part 16 may have a circular cross section, but may also be square as shown. The lower end surface of the head Ig is formed flat, and this allows a strong buckling force to be applied to the rivet body shaft portion when the man Yrel is pulled. The diameter of the head 15 is the rivet body 1.
The diameter of the shaft portion 2 is approximately equal to the diameter of the shaft portion 2, so that it can be easily inserted into the mounting hole of the member to be mounted.

The rivet body 12 consists of a hollow cylindrical shaft portion 20 and a flange 21 formed at one end of this shaft portion 2G, and the diameter of the hollow hole 13 is formed to be slightly larger than the diameter of the mandrel shaft portion 14. The length of the rivet body 13 (mainly the length of the shaft portion 20) is the length of the plate 1 as the member to be attached in FIG.
, 2 can be arbitrarily selected to adapt to the thickness.

The mandrel 11 (FIG. 3) and the rivet body 12 (FIG. 9) are arranged such that the mandrel head 15 is located at the end of the rivet body opposite to the flange 21.
The shaft portion 14 of the rivet body is inserted into the rivet main shaft portion 20 (the third
Figure) 0 After this assembly, the rivet body shaft portion 20 is assembled as shown in Figure 6.

The mandrel shaft portion 14 is processed so that its outer diameter is reduced together with the inner diameter at a position corresponding to the second small diameter portion 17 . This processing can be easily performed by pressure forming using two rollers.

FIG. 1 shows how plates 1 and 2 are fastened to each other using a blind rivet 10 according to a first embodiment of the present invention. The rivet body shaft portion 20 is inserted into the mounting hole No. 2 with the mandrel head 15 at the beginning until the flange 21 comes into contact with the flange 21. Mandrel shaft portion 1 protruding toward the flange 21 side
When the mandrel shaft portion 14 is pulled in the direction of the arrow in step 0 (B) in which the nose (not shown) of the tensioning shank is attached to 4, the mandrel head 15 is attached to the rivet body shaft portion 20.
A force that deforms the shaft portion 20 is applied to the end surface of the shaft portion 20. This force becomes large when the lower surface of the mandrel head 15 is formed flat, so it is preferable to form the line surface flat. This force is first concentrated on the reduced diameter portion 23, and The portion 23 is constricted inward.

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The portions of the rivet body shaft 20 other than 23 begin to buckle or expand outward.This expansion is regulated by the diameter of the mounting hole in the plate 1゜2, but outside it becomes larger than the mounting hole. buckle. Subsequent step (C) As shown in Ic, when the mandrel shaft 14 is further pulled, the mandrel head 15 enters into the rivet main shaft 20,
Both plates 1.2 from the buckling part of the shaft part 20 and the flange 21 and k
Tighten it so that it is firmly clamped, and the entry of the head 15 is stopped! The handle shaft portion 14 is broken at the broken small diameter portion 16.

In the complete fastening state shown in FIG. 1(C), the plate 1.2 is firmly fastened by the flange 21 of the rivet body and the buckled portion of the shaft portion 20. Then, due to the inward constriction K of the reduced diameter portion 23 of the rivet body shaft portion 20, the in-drel shaft portion 14
Since the second small diameter portion 17 of the rivet is clamped, the mandrel portion remaining within the shaft portion 20, including the head 15, is fixed within the rivet body. This fixation eliminates the movement of the mandrel head 15 as shown in FIG. 1(E), and thus eliminates the generation of abnormal noise.

Further, as explained in FIG. 1, in the blind rivet according to the present invention, the reduced diameter portion 23 of the rivet main shaft portion 20 first constricts inward, and buckling starts from this position, so the mandrel head 15 is at this position. Even if the mounted member 1.2 is made of a soft material such as plastic, it will not cause a situation where the mounting hole of the mounted member is bought as shown in Fig. 2. do not have.

Furthermore, by providing the reduced diameter portion 23 of the rivet body shaft portion 20 at an appropriate position with respect to the mounting hole of the member to be attached 1.2, the shaft portion 20 between the reduced diameter portion 23 and the flange 21 also expands. Therefore, the gap between the mounting hole of the mounted member and the shaft portion 20 is filled. Therefore, there is no backlash as shown by arrow 9 in FIG. 1(E). A second embodiment is shown, and in this example, the rivet main shaft portion 2G includes:
In addition to the reduced diameter portion 23, a second reduced diameter portion 24 is formed between the reduced diameter portion 23 and the flange 21. When the second diameter-reduced portion is formed in the shaft portion 20 in this way, the rivet body shaft portion 20 forms one constriction during the fastening operation, as shown in FIGS. 3(B) to (D). Since the buckling portion is formed, the fixing force is more effective than the first embodiment.

And the blind rivet 10' of this second embodiment
This is even more effective when the thicknesses of the plates to be fastened are different, as shown in FIG.

In FIG. 9, the blind rivet 10' on the left side
The blind rivet 10I in the middle of the figure shows the state in which seven thick plates have been fastened together, and the blind rivet 10I on the right side of the figure This shows how seven more plates were added and fastened together.

In either case, the plate, which is the member to be attached, is firmly fastened by the flange 21 and the buckled portion of the shaft portion 20. This is because the buckling position can be started from the position of the reduced diameter part, so that even if the plate thickness changes when multiple reduced diameter parts are provided, the plate is strengthened between the buckling part and the flange 21. This is because it can be tightened.

Figures 1θ (^) to (D) show a blind rivet 10# according to a third embodiment of the present invention. In this example, as shown in FIG.
In addition to the broken small-diameter portion 16 and the second small-diameter portion 17, a third small-diameter portion 18 is formed on the distal side (lower side in the figure) of the broken small-diameter portion 16. This third small diameter portion 18
Like the small diameter portion 17, it is made larger in diameter than the fractured small diameter portion 16 and is reduced in diameter so as not to break there, and has a rectangular cross section, but it may also have a circular cross section.

Further, although the rivet main body is provided with one reduced diameter part as in the second embodiment, the 1a diameter part 23 is not located at a position corresponding to the second small diameter part 17 of the mandrel shaft part 14,
It is formed midway between the broken small diameter portion 16 and the second small diameter portion 1f. Further, the second reduced diameter portion 24 is formed at a position corresponding to the third small diameter portion 18. When formed in this way,
Similar to the blind rivet 10' according to the second embodiment, it not only has a strong fixing force, but also can properly fix plates even if they have different thicknesses.
In addition, in the second and third embodiments, two diameter-reduced portions of the rivet body shaft portion were provided, but the invention is not limited to this, and it goes without saying that three or more reduced-diameter portions may be formed. be. It should also be noted that in the embodiments described above, one or both of the reduced diameter portions of the rivet body shaft are formed to coincide with the small diameter portion of the mandrel shaft. By doing so, there is an advantage that the rivet body can be firmly assembled so that it will not come off from the mandrel shaft. However, this is not essential to the present invention, and the integrity of the rivet body and mandrel will not be impaired simply by frictionally engaging the reduced diameter portion of the shaft of the rivet body with the mandrel shaft. Therefore, the reduced diameter portion of the rivet body does not necessarily have to match the small diameter portion of the mandrel shaft.

Figures 1/(^)-(D) show a blind rivet 10111 according to a fourth embodiment of the present invention. In this example, one reduced diameter portion 23 of the rivet main shaft portion 20 is provided as in the first embodiment (Figs. 3 to 7), but as shown in Fig. 3(e), The position is not between the broken small diameter part 16 and the head 15, but is provided at a position closer to the tip (lower side in the figure) than the broken small diameter part 16 and not in the small diameter part. When formed in this way, the turtle, the first/
As shown in Figures (C) and (D) K, when the mandrel shaft part 14 is pulled in the direction of the arrow, the reduced diameter part 23 constricts inward, and this constriction clamps one second small diameter part and the mandrel after being broken. is fixed to the rivet body. Also, board 1.2
The adhesion force is also strong as in the case of the first embodiment.

In addition, in this fourth embodiment, the third small diameter portion 18 of the mandrel shown in the third embodiment may be provided to form a reduced diameter portion there. Also, not limited to this example, for example, the third
In the embodiment, a second small diameter portion may be formed between the second small diameter portion 17 and the broken small diameter portion 16, and the reduced diameter portion 23 may be formed there. In this case as well, the second reduced diameter portion 24 is not essential and may be omitted. Furthermore, in the first and fourth embodiments, as shown in the second and third embodiments, the rivet body The second reduced diameter portion 24 may be formed in the
Of course, it is also possible to form RK.

Effects of the Invention According to the present invention, the second small diameter portion is formed in the mandrel shaft portion between the small diameter portion to be broken and the head, and the diameter reduction portion is formed in the shaft portion of the main body of the pet at a position other than the small diameter portion to be broken. Since a portion is formed, when the mandrel shaft portion is pulled, the reduced diameter portion thereof becomes inwardly constricted, and this constriction directly securely clamps the second small diameter portion of the mandrel shaft portion. Therefore, the broken mandrel head is fixed within the rivet body and becomes immovable, eliminating the generation of abnormal noise.

In addition, when the mandrel shaft is pulled, the body shaft constricts inward before expanding or buckling, so the mandrel head does not advance beyond this constriction, and the workpiece is Even soft materials will not penetrate through the mounting holes. Furthermore, since % buckling occurs at the inwardly constricted part, that is, the reduced diameter part of the rivet main body shaft, by selecting the position of the reduced diameter part, the rivet main shaft part can be seated in the mounting hole of the mounted member. ◇

[Brief explanation of the drawing]

Figures 1 (A) to (ε) and Figures 2 (^) to (E) are explanatory diagrams showing how plates are fastened using conventional blind rivets, and Figure 3 is an embodiment of the present invention. Partial view of blind rivet mandrel as seen from the front, No. 9
The figure is a partial sectional view of the unprocessed rivet main body of a blind rivet according to an embodiment of the present invention, seen from the front, FIG. 3 is a partial sectional view of the blind rivet before processing according to an embodiment of the present invention, and FIG. A partial sectional view of a blind rivet according to an embodiment of the present invention, FIG. (D) is an explanatory diagram showing how plates are fastened using the blind rivet according to the second embodiment of the present invention, and FIG. 9 is an explanatory diagram showing how plates of different thickness are fastened using the blind rivet of the second embodiment. 10 (A) to (D) are explanatory diagrams showing how plates are fastened using blind rivets according to the third embodiment of the present invention, Figures 1/(^) to (0) is the fourth of the present invention t.
FIG. 3 is an explanatory diagram showing how plates are fastened using blind rivets according to an embodiment. 1, 2------plate (mounted member), 3...
・・・Conventional blind rivet, 4...Mounting hole, 10 e 10', l O', 10Iu
...Blind reheating of the present invention), 11
...Curved mandrel, 12...Curved rivet body,
14...Curved mandrel shaft part, 15...Mandrel head, tS-------broken small diameter part, 17...
...Second small diameter part, 18---Third small diameter part, 20...Rivet main body shaft part, 2! −
-Rivet body flange, 23...1st
Reduced diameter part, 24... Second reduced diameter part. Figure 1 (A) (B) (C)
(A) (B) (C) (D) (E) (D) (E) Section (A) (B) Figure 8 (C) (D) Figure (C) CD)

Claims (1)

[Claims] 1. A hollow rivet body consisting of a shank and a flange at one end of the shank, a shank longer than the rivet body and having an outer diameter that can be inserted into the hollow hole of the rivet, and this rivet. It consists of a mandrel consisting of an enlarged head at one end of the rivet, and the shank of the mandrel is inserted into the shank of the rivet body so that the mandrel head is located at the end of the shank opposite to the flange of the rivet body. , insert the rivet body with the mandrel head first until the flange contacts the mounting hole of the workpiece, and then pull the mandrel shaft strongly from the flange side to expand the rivet body shaft. In the blind rivet which is buckled and the mandrel shaft is broken at the small diameter portion of the mandrel shaft, at least two small diameter portions including the broken small diameter portion are formed in the mandrel shaft, One of the small diameter parts other than the small diameter part is formed at a position closer to the head than the small diameter part, and the outer diameter of the shaft part of the rivet body is A blind rivet characterized in that it is formed with a reduced diameter, and the reduced diameter portion constricts inward when the mandrel shaft is pulled. 2. The blind rivet according to claim 1, wherein the reduced diameter portion of the rivet body shaft portion is formed to correspond to a small diameter portion closer to the head than the fracture small diameter portion of the mandrel. . 3. The blind rivet according to claim 1, wherein the reduced diameter portion of the rivet main body shaft portion is formed between the broken small diameter portion of the mandrel and the small diameter portion near the head. . 4. The blind rivet according to claim 1, wherein the reduced diameter portion of the rivet body is formed at a position of the shaft portion on the tip side of the fractured small diameter portion of the mandrel. 5. The blind according to claim 1, wherein the rivet main body shaft portion has another reduced diameter portion formed between the reduced diameter portion and the flange of the rivet main body. Rivets. 6. Another small diameter part is formed on the shaft of the mandrel closer to the tip than the broken small diameter part, and another reduced diameter part is formed on the rivet body shaft at a position corresponding to this small diameter part. A blind rivet according to claim 1, characterized in that: 7. Another small diameter part is formed in the shaft part of the mandrel between the broken small diameter part and the second small diameter part, and the rivet main body reduced diameter part is formed at the position of the small diameter part. A blind rivet according to claim 2, characterized in that: 8. A patent claim characterized in that the mandrel shaft portion has another small diameter portion formed closer to the tip than the broken small diameter portion, and the rivet main body reduced diameter portion is formed at the position of the small diameter portion. Blind rivets according to item 4 of the scope. 9. The blind rivet according to claim 1, wherein the lower surface of the mandrel head is formed flat.