JPH1078015A - Hollow rivet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce manufacturing cost by preventing a calking crack. SOLUTION: A hollow rivet 1 is constituted of a leg part 3 having a calk part 4 formed with a hollow hole 5 and a head part 2 integrally formed in a rear end of the leg part 3. Here, from a carbon steel wire rod containing Mn in a 0.20 to 0.30% range and containing 0.03% Si, an element material of desired length is obtained, and by obtaining the hollow rivet 1 of desired shape, by a cold press work process 10 generation of a flaw and crack in a calk part is prevented at calking work time, and beautiful appearance is obtained in the calk part. Since the hollow rivet can be manufactured, by a process of manufacture of minimum limit a cost of manufacture can be reduced, the rivet can be inexpensively provided, and, without changing a work process, a hollow rivet of every size can be manufactured. Further, generation of a flaw and crack is prevented, so as to prevent a workpiece from flawing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rivet manufactured without changing the shape of the rivet and without increasing the number of manufacturing steps. The present invention relates to a hollow rivet that is caulked without causing cracks or cracks in the direction.

[0002]

2. Description of the Related Art Conventionally, among rivets consisting of a head and a leg, a hollow rivet in which the tip of a leg is widened and swaged,
In order to prevent the rivet from dropping off from the swaged work, the tip of the leg is expanded outward in the swage operation. For this reason, a hollow hole having a predetermined length is formed along the axis of the leg in the caulked portion at the tip of the leg. In the hollow rivet, the diameter of the hollow hole is usually 70% of the diameter of the shaft portion of the rivet, and it is standard that the depth of the hollow hole is set to 90% of the diameter of the shaft portion.

[0003] However, when hollow rivets are manufactured with such standard dimensional proportions, cracks and cracks are liable to be generated in the caulked portions of the legs, and in order to prevent this, the diameter and depth of these hollow holes are reduced. The dimensional proportions are usually varied in accordance with the application of the hollow rivet. Such a hollow rivet is usually obtained by cutting a carbon steel wire into a desired length, and cutting a material (not shown) having a desired length obtained from the wire in a head forming process 110 as shown in FIG. Part 2
The rivet material (not shown) is formed by forming the hollow hole 5 at the same time when the rivet is formed.

[0004] Thereafter, a desired process is performed in a plating process 112 and a lubrication process 114 to provide a hollow rivet as a product. However, in reality, it is necessary to completely eliminate the problems such as cracks and cracks that occur in the swaged portion of the hollow rivet, despite the fact that it takes time and effort in manufacturing to change the size ratio of the rivet material. Can not.

For this reason, recently, after the rivet material is formed, the rivet material is formed again by chamfering the inner surface of the hollow hole at the tip of the leg portion so as to eliminate the inclination of the end face generated at the time of forming the hollow hole. It has been modified to prevent any cracking or cracking during caulking. The rivet material thus obtained is subjected to the cleaning step 111,
In the annealing step 113, the rivet material having a long leg is annealed at the tip of the leg, and the rivet material having a short leg is entirely annealed. Subsequently, after this step is completed, plating is performed in a plating step 112, and thereafter, in a lubrication processing step 114 such as a wax processing and a lubricating film processing, the surface of the rivet material is lubricated to produce a hollow rivet.

[0006]

However, even when a work is caulked using a hollow rivet manufactured through such a process, the swaged portion can slide to a certain extent with respect to the work, so that the hollow rivet is attached to the work. However, when the tip of the leg expands, the toughness of the material is poor and the tip does not extend sufficiently, and cracks and cracks still occur in the axial direction. In order to prevent the cracks and cracks, various studies have been made on this manufacturing process as in the prior art.For example, for the rivet material leg, the torso portion of the leg can withstand a caulking load and Although the hollow rivet is manufactured by annealing the caulked portion to such an extent that the caulked portion is not cracked or cracked, in reality, as shown in FIG. 5, when the work 20 is caulked, the caulked portion 4 of the leg 3 is formed. Cracks and cracks could not be completely eliminated.

In addition, by increasing the number of steps as described above, the temperature in the annealing process is adjusted or the size of a die for forming a hollow hole in the forging process is changed in accordance with the type of the hollow rivet. For example, the production time is increased, and in multi-product mass production, the production efficiency is poor and the cost rises. Furthermore, when caulking using the hollow rivet commercialized in such a process, the legs of the hollow rivet are swollen and cannot be securely caulked to the work, and
Problems such as impairment of the aesthetic appearance due to the occurrence of cracks and cracks, and problems such as low fastening force have not been sufficiently solved.

[0008] A first object of the present invention is to solve such problems, prevent complete caulking, and reduce the manufacturing cost. A second object of the present invention is to apply a method to work pieces. A third object of the present invention is to obtain a hollow rivet in which the hollow rivet can be reliably inserted, and which is evenly expanded without causing cracks or cracks in the swaged portion.
An object of the present invention is to obtain a hollow rivet in which the slip between the work and the work is improved, and the swaged portion is smoothly expanded.

[0009]

SUMMARY OF THE INVENTION A first object of the present invention is to:
In a hollow rivet composed of a leg 3 having a caulked portion 4 having a hollow hole 5 formed at the tip and a head 2 integrally formed at the rear end of the leg 3, Mn is set to 0.1 as a material component.
A material having a desired length is obtained from a carbon steel wire rod containing 20% to 0.30% and further containing 0.03% of Si. A second object of the present invention is to obtain a hollow rivet manufactured by obtaining a rivet material, and a leg 3 having a caulked portion 4 having a hollow hole 5 formed at a tip thereof, and the leg 3 In the hollow rivet composed of the head 2 integrally formed at the rear end of the metal rim 3, Mn is contained in the material component in the range of 0.20% to 0.30%.
Is obtained from a carbon steel wire rod containing 0.03% by weight, and the raw material is formed in a forging process 10 to obtain a rivet material having a desired shape, and the rivet material contains a lubricant. This is achieved by obtaining a hollow rivet that has been subjected to a lubrication surface treatment in the plating step 12. Further, a third object of the present invention is achieved by obtaining a hollow rivet in which a lubrication surface treatment is a resin coating treatment.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 2, reference numeral 1 denotes a hollow rivet including a head 2 and a leg 3, and a caulking portion 4 at the tip of the leg 3 has a diameter of 90 mm along the center line of the leg 3 from the tip. A hollow hole 5 having a depth of% is formed. The hollow rivet 1 is manufactured from a low-carbon steel wire (not shown), and the wire has at least Mn.
Is in the range of 0.20 to 0.30%, Si is 0.03%,
Each of them is manufactured by cutting a wire having such a material component into a desired length.

The material (not shown) having a desired length obtained in this manner is manufactured from the process shown in FIG. 4, and the material cut to a predetermined length is formed in the forging process 10. It is formed into a rivet material (not shown) composed of the head 2 and the leg 3. At this time, the hollow holes 5
Can be opened. Subsequently, the rivet material formed by forging is transferred to a washing processing step 11, in which an oil component adhered at the time of forging processing is removed. The surface of the rivet material washed in the cleaning process 11 is subsequently dried, and then, in the plating process 12, chrome,
The product is completed by plating with nickel or the like.

Further, in the plating step 12, in order to impart lubricity to the surface of the hollow rivet 1, a resin coating containing a resin coating material such as a silicone resin or a polyethylene resin is also performed. As a result, the rivet material has luster due to plating, and also has lubricity between the rivet material and the workpiece during the caulking operation.

[0013] The hollow rivet 1 manufactured in this manner.
As shown in FIG.
1 and caulked by a caulking device (not shown), the caulked portion 4 at the tip of the leg 3 is expanded outward. At this time, the tip of the hollow rivet 1 is caulked (not shown).
3, slides smoothly along the lower surface of the work 20 and spreads in a substantially circular shape around the axis of the leg 3 as shown in FIG. 3. Further, although a tensile load is generated in the caulking portion 4 in the circumferential direction, cracks and cracks do not occur because the material is rich in toughness. Further, the body does not bulge during the caulking operation.

Further, by chamfering the inner surface of the hollow hole 5 at the tip of the leg in the same manner as in the prior art, the caulking portion 4 can be more smoothly and surely spread in the caulking operation, and stable caulking can be obtained.

[0015]

As described above, according to the present invention, by changing the content of the material component of the carbon steel wire rod as the material of the hollow rivet 1, cracks are formed in the swaged portion in the swaging operation under the same swaging load. Cracks are not generated at all, and the appearance of the swaged portion has an excellent appearance. Further, unlike the related art, the hollow rivet can be manufactured with a minimum manufacturing process without newly adding a forging process for removing the inclination of the rivet tip by annealing.
The cost required for manufacturing the rivet can be reduced, it can be provided at low cost, and it is possible to manufacture hollow rivets of all sizes in a normal manufacturing process without changing the processing steps according to the size of the hollow rivet. Further, since such cracks and cracks do not occur, not only the work is not damaged but also a unique effect such as a reduction in injuries caused by a product using the work can be obtained.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional front view showing a state of caulking with a work.

FIG. 3 is a bottom view of FIG. 2;

FIG. 4 is a process chart showing the production of the hollow rivet of the present invention.

FIG. 5 is a bottom view showing an embodiment of a conventional example of the present invention.

FIG. 6 is a process chart showing the production of a conventional hollow rivet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hollow rivet 2 Head 3 Leg 4 Caulking part 5 Hollow hole 10 Forging process 11 Cleaning process 12 Plating process 20 Work 21 Caulking hole

Claims (3)

[Claims] 1. A hollow rivet comprising a leg 3 having a caulked portion 4 having a hollow hole 5 formed at a tip thereof and a head 2 integrally formed at a rear end of the leg 3; Is contained in the range of 0.20% to 0.30%, and a material having a desired length is obtained from a carbon steel wire rod containing 0.03% of Si. A hollow rivet manufactured by obtaining a rivet material having a desired shape. 2. A hollow rivet comprising a leg 3 having a caulked portion 4 having a hollow hole 5 formed at the tip and a head 2 integrally formed at the rear end of the leg 3, wherein the material component is Mn. Is contained in the range of 0.20% to 0.30%, and a material having a desired length is obtained from a carbon steel wire rod containing 0.03% of Si. A rivet material having a desired shape, and the rivet material is subjected to a lubrication surface treatment in a plating step 12 containing a lubricant. 3. The hollow rivet according to claim 2, wherein the lubrication surface treatment is a resin coating treatment.