JPS6044145A - Production of housing for electronic apparatus or the like and male die for producing rectangular parallelepiped housing - Google Patents

Abstract

PURPOSE:To obtain a rectangular parallelepiped-shaped housing which is tall and has no strain by forming a male die to a prescribed shape by recessing a hollow spherical groove to the top end face of said die thereby balancing and expanding the plastic fluid of a blank material in the long axis and short axis directions. CONSTITUTION:A blank material 3 is loaded to the inside bottom of a female die 2 for forging having the same plane as the plane of a rectangular parallelepiped-shaped housing and a male die 1 narrower by as much as the thickness of the side wall of said housing is press-fitted into the die hole 2a to produce the housing. The forming land 1e of said die 1 is notched and formed to the tapered surface of which the outside circumferential end edge is directed to the top end face. A hollow spherical groove 1h of the arc surface directed toward the center is recessed to said top end face. The fluid of the material 3 is forced to flow earlier in the longitudinal direction of the top end face than in the transverse direction along the surface of said groove 1h in the stage of pressing the material 3 with the die 1.

Description

[Detailed Description of the Invention] - This invention relates to a method for manufacturing a housing for electronic equipment, etc., and in particular for a case (casing) of a storage device of an information equipment, such as a floppy disk drive device, etc., by cold forging of an electromagnetic wave-proof seamless housing. Regarding the manufacturing method.

Conventionally, the case of a floppy disk drive device has a rectangular shape of, for example, 40 x 80 x 20 mm, and is made by cutting a metal plate such as aluminum by sheet metal processing, bending it using several molds, and finally welding it. ing. Therefore, many manufacturing steps are required, resulting in relatively high work costs. .

On the other hand, floppy discs use a storage/readout device using laser beams, but electromagnetic waves are emitted from cars and other vehicles in ordinary cities, and these electromagnetic waves are transmitted through invisible microscopic holes in the welded parts of the casing. The drawback is that they not only interfere with memory reading when they enter the casing, but also alter the memory itself, but it is extremely difficult to completely prevent the intrusion of electromagnetic waves when manufacturing casings by welding. 0 In addition, in order to eliminate these difficulties, it is preferable to manufacture a housing by forging, which does not require welding, but in extrusion forging, manufacturing of a housing with large differences in vertical and horizontal dimensions as described above is difficult, as shown in Figure 1. TS has the disadvantage that the wide side rises up and the narrow side is not sufficiently extruded, resulting in cracks in the ground due to strain at the corners, making it impossible to form the casing.

The purpose of this invention is to overcome these difficulties and provide a method for manufacturing a housing for electronic devices, etc., in which a rectangular parallelepiped housing can be manufactured in one step of forging. In a cold forging method in which a blank piece slightly smaller than the flat surface is loaded into the inner bottom of a forging female die having the same plane, and a male die narrower than the plane by the thickness of the side wall of the casing is press-fitted, the forming land of the male die is A notch is formed in the tapered surface by one angle toward the tip surface of the outer peripheral edge, and a concave spherical port with an arc surface toward the center is formed on the tip surface, so that when the blank is pressurized by the male mold, the concave surface is notched. The present invention relates to a method for manufacturing a housing for an electronic device or the like, characterized in that the blank fluid is formed in a spherical groove surface and flows faster in the longitudinal direction of the tip surface than in the width direction.

According to this invention having the above configuration, since there is a concave spherical groove on the tip surface of the male molding land, when pressure is applied to the male blank, the blank in contact with the tip surface of the molding land becomes plastic. The arc surface of the concave spherical groove surface is gentle in the longitudinal direction, which causes a fast flow in the longitudinal direction, and the rectangular rectangular housing is well-balanced in the long and short axes directions, without causing distortion. It can be forged.

Embodiments of the present invention will be described below based on the drawings. Figure 2 and subsequent figures relate to this invention, Figure 2 is a side view of the male mold, Figure 3 is a front view of the male mold, Figure 4 is a bottom (tip end) view of the male molding land, and Figure 5 is the method of the present invention. FIG. 6 is a front view showing the state immediately before blank pressurization, and FIG. 6 is a front view immediately after forging the casing.

The male punch (punch) 1 is vertically long, approximately rectangular, and is JIS standard S.
K8. A head 1by with a large diameter is formed on the top of the proximal end 1a, and an insertion part IC is formed with a small diameter below the proximal end. A molded land le having a slightly larger diameter is formed at the distal end of the insertion portion 1c via a tapered surface 1d, and a tapered surface 1g directed toward the distal end surface 1f is formed at the peripheral edge of the distal end of the molded land 1e. A concave spherical groove 1h is bored in the groove. Reference numeral 11 in the figure is a boar's neck portion.

In FIG. 5, reference numeral 2 indicates a female type. The female m2 is made of the same material as the male mold. During implementation, mold hole 2a of female mold 2
K blank (material) 3 is loaded, and this blank 3 is made by cutting aluminum into a rectangular bar shape and cutting it into the required dimensions.Other than that, a predetermined aluminum plate is pressed out using Venus. For sectioning or braces, non-shirring planks, use cutter or serrated aluminum pieces.

This blank is heated in an electric furnace, gas furnace, or heavy oil furnace at a temperature of 200° to 600° for 1 to 5 hours depending on its hardness, and then is furnace-cooled or air-cooled for annealing. This may be omitted depending on the hardness of the material.

Next, the narrow side of the material is lubricated by phosphoric acid coating, Alpunch treatment, or Barker treatment, and this is loaded into the mold hole 2a. Then, the male mold is inserted into the female mold 2 mold hole 2a, and the forging press or When pressed using a hydraulic press, a power press, etc., the blank 3 is expanded into a thin rectangular box 4 as shown in FIG. In this case, since the outer periphery of the insertion portion IC is thinner than the outer periphery of the shaped land 1e, the frictional resistance with the blank 3, that is, the casing 4 during forging is reduced.

The housing 4, which is forged by the method described above, has a tall rectangular parallelepiped shape as shown in FIG. 7, and has an opening at the top. This casing 4 is held in an electric furnace, gas furnace, heavy oil furnace, etc. in a furnace atmosphere in the range of 1000 to 500° for 1 to 5 hours, after which it is furnace cooled or air cooled so that no residual particles remain in the product. This process removes stress during pressing and stabilizes the metal structure to make it uniform. In this case, depending on the product, this annealing may be omitted.

Next, the entire length of the casing 4 is machined to a predetermined dimension using a press, a lathe, a milling machine, or the like.

Next, cooling holes, mounting holes, and other necessary processing are performed at necessary locations using a drilling machine, milling machine, press, etc.

Next, the casing 4 is subjected to pickling, caustic treatment, chemical polishing, fist buffing, etc. to remove dirt from the casing, and the entire outer and inner surfaces are subjected to surface treatment such as black alumite treatment. Particularly in floppy disk drives, etc., heat is generated inside the housing, and if the housing is made of aluminum, it reflects heat and cannot be removed, so a black alumite film layer with high heat absorption is formed inside the housing. This black alumite film layer has a high heat removal effect when the outside and inside of the casing are communicated with each other.

The material of the male mold is SKS, and also SKs.

5KD1. SKD, , SKH, , SKH, or cemented carbide can be used, and all parts other than the cemented carbide are rough-machined and then quenched and heat treated to a range of HRC, ~H1 (C, s). Finish and use.

Further, the tapered surface 1 of the tip peripheral edge of the male molded land 1e
g is formed to be inclined in the range of 1° to 60° toward the tip surface 1f. This tapered surface 1g does not need to be formed if the height of the casing 4 is low; in other words, the angle of the tapered surface increases as the height increases;
This is appropriately adjusted depending on the relationship between the length ratio of the long axis and the short axis of the tip surface of the forming land 1e. The hardness of the blank is also adjusted keeping in mind.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a housing manufactured by a conventional method, Fig. 2 and the following are related to the present invention, Fig. 2 is a side view of the male type, Fig. 3 is a front view of the male type, and Fig. 4 is a bottom view of the male type. , FIG. 5 is a front view showing the state at the start of manufacturing, FIG. 6 is a front view showing the state immediately after forging the casing, and FIG. 7 is a perspective view of the casing before processing. 1... Male type (punch) la... Base end portion 1b...
Head ], C... Insertion part 1d... Tapered surface 1e... Molded land 1f...
Tip surface 1g...Teno surface 1h...Concave spherical groove
11... Boar's neck 2... Female mold 2a... Hole 3... Blank (material) 4... Housing 4, 2nd eye, Figure 3', fang 5, fang 6, fang 7 Listen

Claims (1)

[Scope of Claims] (1) A blank piece slightly smaller than the plane is loaded into the inner bottom of the forging female mold, which is approximately on the same plane as the plane of the rectangular casing, and is narrower than the plane by the thickness of the side wall of the casing. In the cold forging method in which a male mold is press-fitted, the molding land of the male mold is formed with a notch in the tapered surface toward the tip surface at the outer peripheral edge, and the tip surface has a concave spherical shape with an arc toward the center. Cold forging is performed by forming grooves so that the blank fluid flows faster in the longitudinal direction of the tip surface along the concave spherical groove surface than in the width direction when the blank is pressurized by the male die. A method for manufacturing casings for electronic devices, etc. (2) The manufacturing method is characterized in that, after the casing forging process, a casing annealing process, a casing mechanical shaping process, and a casing surface treatment process are added. A method for manufacturing casings for electrical appliances, etc. (31 A male mold for cold forging is integrally formed with a substantially rectangular columnar insertion part, its upper head, and a forming land at the lower end of the insertion part,
The molded land has a rectangular tip surface, and the tip peripheral edge thereof is formed into a tapered surface toward the tip @ surface, and the tip surface is provided with a concave spherical groove with an arc surface extending from the peripheral edge toward the center. A male mold for manufacturing a rectangular casing, which is characterized by a cylindrical shape. (4) In the male die, the rectangular parallelepiped according to claim 3, wherein the tapered surface of the peripheral edge of the tip of the molding land is formed within a range of 1° to 60° toward the tip surface. Male mold for housing manufacturing. (5) In the male die, the arc surface of the concave spherical groove formed on the tip surface of the molding land has a groove depth at the center with an inclination of 1/100 to 1/100.
A male mold for manufacturing a rectangular parallelepiped casing according to claim 3 or 4, wherein the male mold is selected within a range of 7/0.