JPS6180678A - Folding method of jacket for magnetic disk - Google Patents

Abstract

PURPOSE:To obtain a folding method less affected by distortion due to heat, and excellent in finished state by heating indirectly a folded part after a sheet for jacket is folded and cooling and shaping forcibly the folded part. CONSTITUTION:When a folding plate 22 is rotated, a sheet is folded twice at approximately the center along the line decide by the top of a spacer plate 20a of a jacket sheet 1. Thus the jacket 1 is folded and cooled without preheating, and the accuracy after the folding is held. Continuously the indirect heating is carried out by a heater 30 mainly with use of radiant heat from an infrared ray heater 31 of the heater 30. Thus heating can be executed from a comparatively remote place without moving the heater to a subject to be heated, and external force will not apply to the subject. Moreover, the heater is not pressed on the folded part, where by a cooled forming part 41 can abut immediately on the folded part without retreating process of a heater part. After the heating is terminated, the cooled forming part 41 of a cooler 40 is pressed on the folded part, and the rapid cooling of the jacket sheet 1 and forming of an edge are simultaneously carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for folding a magnetic disk jacket for housing a flexible disk magnetic disk used in a flexible disk drive device or the like.

[Prior art and its problems] A jacket for this type of magnetic disk is made of a PVC sheet or the like with a non-woven fabric adhered to the inner surface, and as shown in Figure i1, a center hole 2, a head window 3.
Drill index holes 4 and apply fusion method 5 on three sides...
The flat rectangular mold sheet 1 which has been folded is folded in half, and the two opposing sides of the fusion method 5 are folded so that the double-folded sheet 1 is overlapped and folded, as shown in Fig. 2. As shown in the figure, a square jacket with three sides closed is obtained.

In addition, a part of the MI bonding allowance 5 bent in FIG. 2 is fused using a heat press, and the magnetic disk is inserted from the open side (the side with the fusion bonding method 5 that is not bent). After that, the remaining fusion method 5 is bent, and this fusion method 5 is also fused in the same manner.

By the way, in the conventional folding of the mold sheet 1, in order to facilitate the folding of the mold sheet 1, a method is generally adopted in which the sheet a stand etc. in the folding device is heated to facilitate the workability. Easy.

Although the effect of springback after cooling is small, since the entire mold sheet 1 is heated on a sheet mounting table, the influence of this heat extends beyond the folded parts, causing waviness and wrinkles in the sheet, and damage to the nonwoven fabric. Wrinkles and peeling MW were likely to occur.

Therefore, in order to improve the above-mentioned drawbacks, the approximate center of the rectangular jacket sheet provided with the fusion method is folded in half, and the fusion method on both sides of the sheet I is doubled. A magnetic disk jacket that is further folded onto the folded sheet and folded, then a heater is applied to each folded area to heat and shape the folded area, and then the folded area is forcibly cooled. In 1982, a patent application was filed by Chojin for the method of bending.
It was proposed as No. 51540.

However, in this method, the heater is pressed directly against the folded jacket sheet to heat and shape it, so the heater must be moved directly to the folding point, and after heating, the heater must be folded by 11 tons. Since it had to be separated from the area and then cooled, it took longer to cool it down than to heat it up.

In addition, in the areas where the heater was pressed, the surface of the jacket sheet sometimes lost its matte finish and became a smooth surface.

[Object of the Invention] The present invention has been made in view of the above points, and its object is to provide a method for folding a jacket for a magnetic disk that is less affected by distortion due to heat and has a good finish. .

[Summary of the Invention 1] As a result of various studies on how to fold a jacket for a magnetic disk, the inventor of the present invention discovered a method of folding a jacket for a magnetic disk. It has been found that the above objectives are achieved.

[Embodiment of the invention] Hereinafter, an embodiment of the invention will be explained in detail with reference to the drawings.
do.

FIG. 3 is a front view of the main part of the automatic folding machine for the bottom part (middle part) of jacket sheets, and FIGS. 4(A) to 4(E) are process explanatory diagrams.

In FIG. 3, l is a jacket sheet and corresponds to that in FIG. Reference numeral 20 denotes a presser member that presses down the jacket sheet 1 when it is folded.A spacer plate 20a is attached to the presser member 20, which acts as a force when the jacket sheet l is folded and determines the bending line. After positioning the jacket sheet 1, this presser member 20 is automatically pressed against the jacket sheet 1 of the unfolded sheet mounting table 21J: by an appropriate conveying means such as an air cylinder of a folding machine, and the jacket sheet 1 is Seat IIi! It is designed to be brought into close contact with the placing stand 21.

Reference numeral 21 denotes a sheet mounting table, on which approximately half of the jacket sheet 1, ie, the side on which the welding margin 5 is provided, is placed. Reference numeral 22 denotes a folding plate for folding the jacket sheet l into two at its central portion, and is rotatable with respect to the sheet a placement stand 21, and when the seat jacket 1 is attached, it is folded into the shape shown in FIG. 4(B). A part of the jacket sheet l is held in place.

Further, 23 is a sheet positioning stand on which a pin (stopper) 24 for positioning the jacket sheet l is provided.

Hereinafter, the folding process of the jacket sheet (1) having the above structure will be explained with reference to FIG.

Although the sheet mounting table 21 is shown horizontally for convenience of illustration, in this embodiment the sheet mounting table 21 is actually shown in FIG. The folding plate 22 and the sheet positioning table 23 are entirely inclined at an angle of approximately 45 degrees with respect to the horizontal plane. , along the slope in Figure 4 (A
) and stops at the position shown in FIG. 4(A), which is positioned by the positioning bin 24 provided on the seat positioning table 23.

When the position of the jacket sheet 1 is determined, this is detected and the presser member 20 is lowered onto the sheet mounting table 21, and the spacer plate 20a presses the jacket sheet 1-1 onto the sheet mounting table 21 and brings it into close contact. The zero-order folding plate 22 rotates and the jacket sheet 1 reaches the state 4'1A(B).
The sheet is folded in half approximately at the center along a line determined by the tip of the spacer plate 20a, resulting in the state shown in FIG. 4(C). The jacket sheet 1 in this folded state is at the position indicated by the 31-th one-point button 1a.

In this way, in the step of folding the jacket sheet 1, the jacket sheet 1 is coldly folded without preheating, and the accuracy after folding is maintained. This is to prevent deformation of the jacket sheet 1, Wl, wear-out of the nonwoven fabric, peeling, etc. due to the influence of preheating (the influence of thermal stress on the entire sheet).

Subsequently, indirect heating is performed using the heating device 30.

This is done mainly by utilizing radiant heat from the external heater 31 of the heating device 30, as shown in FIG. 4(D). In this embodiment, a ceramic heater mainly used for wavelengths of 3 gm to 7 gm is used as the infrared heater 31, and has good absorption efficiency with respect to the jacket sheet 1 made of vinyl chloride.
Only the bent area can be locally heated in a very short period of time.

The bent portion is irreversibly heat-treated by so-called springback. In this way, it is possible to heat the object from a relatively long distance without moving the heater directly to the object to be heated.
It is now possible to form any subsequent edge shape without applying any external force to the object to be heated. In addition,
It is important to note that since the heater is not pressed against the bending part, the cooling molding part 41, which will be described later, is the heater part! ! It becomes possible to contact the bent part immediately without any need to avoid the ball. Therefore,
The combination of local heating and immediate cooling allows heat from the local area to be removed without affecting other areas.

Here, if the radiant heat from the infrared heater 31 is weak, the heating device 30 is provided with a cover part provided with a reflector that covers the heated part, and this cover part is moved during heating, so that the heat near the heated part is It may also be configured to prevent state spread.

When the heating of the bent portion shown in FIG. 4(D) is completed, the fourth
The cooling molding part 41 of the cooling device 40 shown in FIG. 4(E) is pressed against the folded part, and the heated jacket sheet l is rapidly cooled and the edges are molded while being recycled.

A cooling water pipe 42 for circulating cooling water is disposed inside this cooling molding section 41, and quickly removes the heat transferred to the jacket sheet 1 before the heat is transferred to locations other than the vicinity of the bent portion. It is meant to be removed.

At this time, the cooling molded part 41 has a U-shaped cross section or a rectangular (long f)
-) It is important to provide an edge molded portion 43 consisting of a groove, and the bent portion of the jacket sheet 1 forms an edge molded portion 43.
3 and is cooled from three sides, further increasing the cooling effect. (Compared to air blow cooling, since it is direct contact cooling, the cooling is extremely rapid.) At this time, the jacket sheet l is only indirectly heated, and the bent portion is cooled and cooled by the edge forming part 43 of the forming part 41. It can be molded into any shape according to the shape.

As a result, it was confirmed that the jacket sheet 1 was not affected by thermal distortion at all, and that a product with an extremely good finish could be obtained at a high yield.

In the above embodiment, the case where the jacket sheet L is folded into 2 tons is explained as an example, but the fusion width 5 of the jacket sheet L folded into 2 tons in this way is applied to the sheet folded into 2,000 tons. It goes without saying that even when the sheet is further overlapped and folded, indirect heating and forced cooling can be performed in the same manner, and the same effect can be obtained.

[Effects of the Invention] As explained below, according to the present invention, it is possible to heat only the necessary area without directly contacting the heater to the object to be heated, and it is also possible to cool the object immediately after heating. Heat can be quickly removed by contact cooling, preventing unnecessary heating from adversely affecting other parts, and the edge shape can be made arbitrarily, making it possible to prevent other parts of the jacket sheet from being exposed to heat. It is possible to easily and reliably obtain a jacket sheet with an extremely good finish without distortion, and its value is high.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing the jacket sheet before folding, Fig. 2 is a plan view showing the jacket sheet after folding, Figs. 3 and 4 relate to an embodiment of the present invention, and Fig. 3 shows the jacket sheet. A north view of the essential parts of the bottom automatic folding machine, and FIGS. 4(A) to 4(E) are process explanatory diagrams. In the figure, 1... Jacket sheet, 20... Pressing member, 21... Sheet mounting table, 22... Folding plate, 2
3... Seat positioning base, 24... Positioning pin. 30... Heating device, 31... Infrared heater, 40.
. . Cooling device, 41 . . . Cooling molding section, 42 . . . Cooling water pipe, 43 . . . Edge molding section. Patent applicant Copal Co., Ltd. Figure 1
Figure 2 Figure 3 b

Claims (4)

[Claims] (1) A part of the jacket sheet is fixed by a fixing means, the jacket sheet is bent by a bending means around the fixed position by the fixing means, and then the bent part is heated by radiant heat. 1. A method for folding a jacket for a magnetic disk, which comprises heating the jacket mainly by indirect heating means, and then forcedly cooling and shaping the folded portion. (2) The magnetic force recited in claim 1, wherein the forced cooling shaping is performed by pressing a cooling molding part against the bending area immediately after heating the bending area. How to fold a disc jacket. (3) The method for folding a jacket for a magnetic disk according to claim 2, wherein cooling water is circulated through the cooling molding section. (4) The jacket for a magnetic disk according to claim 2 or 3, characterized in that the cooling molded part is provided with an edge molded part formed as a groove into which a bent part is fitted. folding method.