JP2002323020A - Rivet caulking structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To caulk a rivet so as to produce no clearance between the rivet and a rivet hole. SOLUTION: Since a head part 4b side of the rivet 4 is hard to expand and easy to produce a clearance between the rivet hole 4 and the rivet in a caulking state, a core hole 4c is set in the head part 4b side, in a state of easily being compressively deformed at caulking, and annealed if necessarily. Caulking makes the head part 4b side of the rivet 4 to be easily deformed to prevent the clearance between the rivet hole and the rivet from producing and prevent the rivet from fatigue fracture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for manufacturing a plurality of plate members,
Regarding a caulking structure for caulking with a rivet with a head, the rivet includes a small-diameter rivet called a pin.

[0002]

2. Description of the Related Art When a rivet with a head is swaged in a rivet hole, the shaft of the rivet expands and expands in the rivet hole, and the gap between the rivet and the rivet hole tends to be filled. The longer the head, the harder it is to expand the diameter on the head side, and a gap is created between the plate member on the head side and the rivet, making the caulking state uncertain. Is significantly reduced.
FIG. 4 shows an example in which the plate members b and c are fixed to the thick plate member a with the rivet d. Since d2 is generated and there is play, there is a possibility that fatigue fracture may occur in this play.

In order to prevent this, in the invention of Japanese Patent Application Laid-Open No. 2000-18222, a punch having a conical projection is used as a receiving punch on the head side to promote diameter expansion, or the diameter or shaft of a rivet hole is increased. The diameter of the part is varied to eliminate the gap. However, according to this means, it is understood that the punch has a complicated structure and has a problem in durability, and that the structure of the rivet hole and the shaft portion is complicated and expensive.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate a gap between a shaft portion on the head side of a rivet and a rivet hole by simple means.

[0005]

Means for solving the above-mentioned problems are as follows.
As described in each claim, the means of claim 1 is to form a rivet hole having a substantially concentric diameter in a plurality of plate members, insert a rivet shaft having a head into the rivet hole, and attach the head to the rivet hole. In the rivet caulking structure where the plate end is integrated by caulking the shaft end portion with the receiving punch and caulking with the punch, a core hole is provided on the head side of the rivet from the end face of the head to the inside of the plate member near the head According to this means, the hollow portion of the shaft portion has a small cross-sectional area, and is easily compressed and deformed to form a rivet hole. Can be swaged without any gap between them.

A second aspect of the present invention is characterized in that, in the first aspect, a rivet whose hardness on the head side is reduced by annealing treatment is used. According to this means, the head-side portion of the shaft portion is soft and thus can be easily compressed and deformed, so that no gap is formed between the shaft portion and the rivet hole.

A third aspect of the invention is characterized in that, in the first or second aspect, the length of the core hole is equal to or greater than the thickness of the plate member on the head side. According to this means, the portion where the diameter can be easily expanded covers the entire thickness of the plate member on the head side, and reliable fixing can be performed.

According to a fourth aspect of the present invention, in the third aspect, the length of the core hole after the caulking is three times the length of the rivet after the caulking.
0% or less. If the length of the core hole is too long, the diameter near the center of the rivet tends to be larger than that near the head, and a gap is likely to be formed near the head. Hateful. If the core hole has a length in this range, processing is easy.

According to a fifth aspect of the present invention, in the first, second, third or fourth aspect, the inner diameter of the core hole is 20% to 60% of the outer diameter of the shaft portion of the rivet. If the inner diameter of the core hole is smaller than the above range, it is difficult to process and the cost is high, and if it is larger than the above range, the thickness of the shaft portion is reduced and the strength is reduced. Can be fixed to

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show an example in which plate members 2 and 3 are caulked to both surfaces of a thick plate member 1 with rivets 4, and the rivet 4 is received by a head receiving a punch, and a shaft end is pressed by a caulking punch. I'll be scolded. The rivet holes 1a, 2a, 3a of each plate member are formed concentrically and with the same diameter. The rivet mentioned here may be a small-diameter rivet called a pin.

The rivet 4 is, as shown in FIG.
It has a shaft portion 4a, a head portion 4b, and a core hole 4c. The length of the core hole 4c is slightly longer than the thickness of the plate member 2. If the head 4b and the core hole 4c are formed by cold working and have a large work hardening, it is desirable to perform annealing for softening.

When this rivet is inserted through the plate member as shown in FIG. 1A and swaged by the punches 5 and 6, in the middle stage of the swaging, as shown in FIG. , The hollow portion starts to swell and the rivet holes 1a,
The diameter is expanded to 2a and 3a. In the latter period when a high load is applied, the main portion and the shaft end of the shaft portion 4a are deformed, as shown in FIG. 2C, and the outer diameter of the main portion of the shaft portion 4a is changed from D1 before compression by rivet. D2 is equal to the hole diameter.

After caulking, the rivet 4 becomes as shown in FIG. 1 (b), and there is no gap between the plate members 1, 2, and 3, so that the rivet is not loosened, and the rivet is repeatedly placed between the plate member and the rivet. Since no impact occurs, no fatigue fracture of the rivet occurs.

Further, as shown in FIG. 3, it is more desirable that the annealing process is softer than a general portion of the shaft portion which is not subjected to cold working. In FIG. 3B, the hardness of the rivet 4 in the cold-worked state is extremely high near the head as shown by the curve A, but when the annealing for removing the strain stress is performed, the hardness as shown in the curve B is obtained. If the vicinity of the part is softened more than the general part, the head side of the shaft part will be
In combination with the presence of c, the rivet is very easily deformed. First, since this portion is filled in the rivet hole, the pressing force is concentrated on the remaining portion, and the remaining portion is well caulked.

In the rivet 4, the length of the core hole 4c in the shaft portion is desirably slightly longer than the thickness of the plate member 2 on the head side, as described above. The members are securely fixed. Also, the length of the core hole 4c is desirably within 30% of the length of the shaft portion after caulking, and in this range, the diameter of the head side can be reliably increased. If it exceeds, the diameter is enlarged near the middle of the shaft portion, but a gap is likely to be formed near the head. The inner diameter of the core hole 4c is suitably from 20% to 60% of the outer diameter of the shaft portion. If it is less than 20%, it is difficult to make a hole, and if it exceeds 60%, the wall thickness becomes thin and the diameter is easily expanded. There is an advantage, but the strength is reduced.

[0016]

As described above, claims 1, 3, 4, or 5
According to the means, the head side of the shaft portion is easily compressed and deformed when the rivet is swaged by the core hole provided on the head side of the rivet. Therefore, there is an effect that fatigue fracture of the rivet does not occur. According to the second aspect of the present invention, since the hardness on the head side is low, the occurrence of a gap in this portion is reliably prevented.

[Brief description of the drawings]

FIG. 1 is a process explanatory view of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a deformed state of a rivet.

FIG. 3 is an explanatory diagram showing an example of a rivet hardness distribution.

FIG. 4 is a sectional view of a conventional example.

[Explanation of symbols]

 Reference Signs List 1 thick plate member 2, 3 plate member 4 rivet 4a shaft 4b head 4c core hole 5 receiving punch 6 caulking punch

Claims (5)

[Claims] 1. A rivet hole having substantially the same diameter is formed in a plurality of plate members, a shaft portion of a rivet having a head is inserted into the rivet hole, the head is received by a punch, and a shaft end is swaged by a punch. In the rivet caulking structure that integrates the plate members by crimping, a hollow portion is formed on the head side of the rivet from the end face of the head to the inside of the plate member close to the head, and a hollow portion is formed by caulking pressure. A rivet caulking structure characterized by expanding the diameter of the part. 2. The rivet caulking structure according to claim 1, wherein a rivet whose hardness on the head side is reduced by an annealing process is used. 3. The rivet caulking structure according to claim 1, wherein the length of the core hole is equal to or greater than the thickness of the head side plate member. 4. The rivet swaging structure according to claim 3, wherein the length of the core hole after swaging is 30% or less of the length of the rivet after swaging. 5. The rivet according to claim 1, wherein the inner diameter of the core hole is 20% to 60% of the outer diameter of the rivet shaft.
% Rivet caulking structure.