JPH0640427B2 - Method of manufacturing shutter for magnetic disk cassette - Google Patents

Description

The present invention relates to a method for manufacturing a shutter for a magnetic disk cassette.

[Conventional technology]

There is known a magnetic disk cassette such as a floppy disk in which a head access hole of a cassette housing can be closed by a shutter member to prevent dust. As shown in FIG. 3, this shutter has an outer shape obtained by bending a thin plate of stainless steel or the like into a channel shape (U-shape) having a pair of facing surfaces 1a and 1b. FIG. 4 is a simplified illustration of the manufacturing process, in which a U-shaped rear part 2 is left unpressed into a developed contour as shown in FIG.
It is manufactured by a continuous progressive press process in which it is bent into a letter shape, and finally the U-shaped rear surface portion 2 is cut and separated into separate shutters 1.

The hole 3 formed in the back surface portion 2 of the shutter 1 shown in FIG. 3 is an insertion hole for the shutter closing pin on the drive device side that operates when the magnetic disk cassette is taken out from the drive device, and also the back surface of the shutter 1 Side edge 4 of part 2
Is the contact position of the shutter opening pin on the drive device side that operates when the cassette is inserted into the drive device.

The dimension a (the distance from the side edge of the hole 3 to the rear side edge 4) and the dimension b (width of the rear portion 2) shown in FIG. 3 are related to the mechanical position of the shutter opening pin, If there is a manufacturing error in the press, a malfunction will occur.

However, as shown in FIG. 6, a convex portion or a concave portion 5 may be formed on the rear side edge 4 due to a positioning error at the time of cutting and separating, that is, the accuracy of the forward press. If is attached to the drive device, there is a possibility that automatic opening by the opening pin (or arm) 6 of the shutter cannot be performed.

In the manufacturing process chart of FIG. 4, punching (punching), bending, and cutting are performed in this order in order to maintain the continuity of the process and to carry out the manufacturing by the progressive feed type automatic press machine. For example, when punching the entire outer shape of the shutter 1 including the rear side edge 4 at the time of punching and bending the individual punched shutters, a very high dimensional accuracy can be obtained. Manufacturing becomes difficult, and the production efficiency is drastically reduced.

[Problems to be solved by the invention]

An object of the present invention is to provide a method of manufacturing a shutter in which extremely high accuracy can be obtained without reducing the production efficiency in view of the above problems.

[Means for solving problems]

A method of manufacturing a shutter for a magnetic disk cassette according to the present invention includes a shutter made of a metal thin plate bent in a U shape,
A method of manufacturing a shutter for a magnetic disk cassette, which is displaceably mounted so that a head access hole of a cassette housing can be opened and closed, comprises a continuous progressive pressing step using a long thin metal plate as a raw material, and the pressing step includes: , A pair of facing surfaces 1a, 1b of the U-shaped shutter 1
Punching step in which the contour lines including one of the two facing surfaces and the back surface portion 2 connecting these facing surfaces are press punching lines, and punching is performed so that the other part of the facing surface becomes a continuous portion 15 between the continuous shutters. B, a bending step of bending so that the pair of facing surfaces 1a and 1b are formed, and c, the connecting portion 15 is punched using a part of the other outline 14 of the facing surface as a cutting line, It is characterized in that it comprises a cutting step of separating into individual shutters.

[Action]

Since the cutting line in the final cutting step is a part other than the side edge of the back surface portion 2 and the dimension between both side edges of the back surface portion 2 is determined by the outer shape punching in the first step, even if the continuous progressive pressing step is adopted. Dimensional accuracy of important parts is secured.

〔Example〕

FIG. 1 is a perspective view showing an external appearance of a magnetic disk cassette provided with a shutter according to the invention. A shutter 1 made of a stainless thin plate bent in a U shape is slidably attached to a side edge of a cassette housing 10 and moved to move the housing. The head access holes 11 of 10 are opened and closed.

FIG. 2 shows a manufacturing process of the shutter shown in FIG.
Is a plan view in the punching process, and includes one of a pair of facing surfaces (1a) of the shutter 1 and both side edges 4 of the back surface 2 which are generated when the shutter 1 is bent, and the outline of a portion extending to the other facing surface 1b. 13 is punched out together with the hole 3 in the back surface part 2. In order to carry out the subsequent bending step and separating step in a continuous sequence, the outline line 14 of the lower half of the facing surface 1b is left without punching, and the individual shutters 1 are kept connected through the connecting portions 15. Supply to the next bending process.

In the bending step of FIG. 2 II, one of the facing surfaces 1 a is taken along the bending line 16 and is shown in FIG. 2 II a (plan view) and b (cross-sectional view).
In the bending step shown in FIG. 2 and in the next bending step shown in FIG. 2, the other facing surface 1b is bent along the bending line 17 as shown in plan view III (a) and sectional view III (b). Bend it in.

In the next cutting step shown in FIG. 2 IV, the remaining portion of the facing surface 1b is cut along the outline 14 and cut into individual shutters 1. The cutting line corresponding to the outer shape line 14 of the facing surface 1b has a level difference portion 18 more than that of the rear side edge 4 (reference end surface).
It is preferable to allow it to enter a little inside by passing through so that the unevenness (deviation) of the cutting line in the line feed direction with respect to the reference cross section can be absorbed. In this case, as shown in FIG. 2, the contour line 13 of the facing surface 1a is also set to be slightly inside the side edge 4 following the contour line 14.

〔The invention's effect〕

According to the method of manufacturing a shutter for a magnetic disk cassette of the present invention, a shutter is manufactured by a continuous progressive press process using a long thin metal plate as a raw material, through each process of outer shape punching, bending, and cutting, and a U-shaped shutter is manufactured. The outer shape (dimensions) of the back surface portion 2 is determined by the punching step, and the outer shape lines other than the back surface portion 2 are used as the cutting lines in the final cutting step. Even if the dimensional accuracy of the cutting line position is poor, it does not affect the dimensional accuracy of the back surface portion 2, so the side edge 4 of the back surface portion 2
Can be the reference surface or the working surface of the automatic shutter opening / closing mechanism.

[Brief description of drawings]

FIG. 1 is a perspective view of a magnetic disk cassette equipped with a shutter according to the present invention, FIG. 2 shows a continuous progressive press step, FIG. 2I is a plan view of a shutter in an outer shape punching step, and FIGS. 2A and 2B are plan views and sectional views of the shutter in the bending step, FIGS. 2A and 2B are plan views and sectional views of the shutter in the bending step, respectively. 3 to 6 show a conventional example, FIG. 3 is a perspective view of a shutter, FIG. 4 is a manufacturing process drawing, FIG. 5 is a shutter plan view showing a punching outer shape in a punching process, and FIG. It is a perspective view of a shutter after the end of a bending and cutting process. In the reference numerals used in the drawings, 1 ... Shutters 1a, 1b ... Opposing surface 2 ... Rear surface 3 ... Hole 4 ... Rear side edge 11 ... Head access hole 13, 14 ... Outer line 15 ...... It is the connection part.

Claims (1)

[Claims] 1. A method for manufacturing a shutter for a magnetic disk cassette, wherein a shutter made of a metal thin plate bent in a U shape is displaceably mounted so as to open and close a head access hole of a cassette housing. A continuous progressive pressing process using a metal thin plate as a raw material is provided, wherein the pressing process presses an outline including a, one of a pair of facing surfaces of the U-shaped shutter, and a back surface portion connecting these facing surfaces. A punching step in which a line is punched out so that the other part of the facing surface is continuous with the connecting portion between the continuous shutters; b, a bending step in which the pair of facing surfaces are bent, and c, A shutter for a magnetic disk cassette, which comprises a cutting step in which the connecting portion is punched out using a part of the other outline of the facing surface as a cutting line to separate the shutter into individual shutters. Manufacturing method.