Method for manufacturing a caulked assembly

#The present invention relates to a high-strength processing technique that is capable of firmly fixing a hollow or solid columnar body to a plate-like body.

#Conventionally, a processing technique of this kind has been performed in the following manner as in Patent Document 1. A flange portion is formed on a midway part of a shaft body as shaft caulking, and a circular hole is punched on a plate-like body which is a press component as a subject of assembly. A tip of the shaft body which is inserted through the circular hole is crushed by a caulking machine for exclusive use so that the press component is sandwiched between the crushed head part of the shaft body and the flange portion to thereby assemble the shaft body with the plate-like body. Alternatively, a more complicated special shape is previously formed on the shaft body, and the shaft body is press-fitted into the circular hole formed in the press component to thereby join the shaft body to the press component.

#However, a large flange portion needs to be provided on the midway part of the shaft body in order to sandwich the press component between the crushed head part of the shaft body and the flange portion. Accordingly, it is necessary to cut a shaft material that is approximately 50% thicker than a shaft diameter required for using as a product to produce a flange shape, which increases material and processing costs. Further, a high manufacturing cost is required also for forming the special shape, which limits the cost reduction.

#FIGS. 1(a) to 1(c) are explanatory diagrams illustrating a manufacturing method of a caulked assembly according to a first embodiment of the present invention;

#FIGS. 2(a) to 2(c) are explanatory diagrams illustrating a modification of the manufacturing method of the first embodiment;

#FIGS. 3(a) to 3(c) are explanatory diagrams illustrating a thick portion;

#First, the first embodiment of the present invention will be described with reference to FIG. 1(a) to FIG. 8(c).

#In the present invention, a caulked assembly A of a metallic plate-like body 1 with a hollow or solid columnar body 2 is manufactured. In the present embodiment, as shown in FIGS. 1(a) to 1(c), a mounting hole 10 for inserting and assembling the columnar body 2 is provided in the metallic plate-like body 1, and a thick portion 11 is formed along an inner circumferential edge of the mounting hole 10. Thereafter, as shown in FIG. 1(a), the columnar body 2 is inserted into the mounting hole 10 of the plate-like body 1 so that the plate-like body 1 is set in an assembly position on an outer circumferential surface of the columnar body 2. Further, as shown in FIGS. 1(b) and 1(c), the thick portion 11 is compressively pressed from an axial direction of the columnar body 2 so as to be plastically deformed toward a center of the mounting hole 10 to thereby tighten and fix the thick portion 11 to the outer circumferential surface of the columnar body 2.

#As just described, the present embodiment does not have a conventional structure in which a circumferential groove is formed on a columnar body, and a thick portion of a plate-like body is caused to bite into the circumferential groove, but has a structure in which the thick portion 11 is fixed to the outer circumferential surface of the columnar body 2 by pressure. Therefore, grooving for forming a circumferential groove is not required and the caulked assembly can therefore be manufactured at a low cost. In addition, reduction of the strength of the columnar body 2 can be prevented, which makes it possible to assemble the columnar body 2 which is slimmer than a conventional columnar body with the plate-like body 1. The caulked assembly A is suitable for electronic components or the like. However, the caulked assembly A can, of course, be applied to other various components and products. For example, the caulked assembly A can be utilized in various forms such as a form of an assembly of a support plate on which components such as a circuit and a fan motor are placed with a strut member in the internal structure of a product, and a form of an assembly of components themselves such as a plurality of cylindrical bodies with a base plate when a heat sink is constructed by assembling the columnar bodies with the base plate.