JPS6194289A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To reduce the cost of a magnetic recording/reproducing device by forming a sloping drawing part to a metallic main body substrate to use the drawing part integrally as a core when a synthetic resin matter is molded and to obtain a sloping attachment part and putting a rotary magnetic drum directly on the sloping attachment part. CONSTITUTION:The sloping drawing part 11-1 is formed previously on the metallic main body substrate 11 by a drawing process. Then the substrate 11 is put into a metallic mold for injection molding, and a synthetic resin matter is connected to a drawing part integrally through an injection molding process. Thus a sloping attachment part 12 is formed for the synthetic resin matter. The accuracy of the part 12 has no relation at all with the accuracy of the part 11-1 of the substrate 11 in a molding mode. In addition, the problems of the synthetic resin matter such as the change of measurements due to the rigidity and the temperature change of the resin, the cracks due to the impact load of dropping, etc. can be improved greatly since the part 12 uses the substrate 11 as its core.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is directed to a cassette tape having a built-in reel hub on which a magnetic tape is wound.The magnetic tape is drawn out of the cassette and wound at a predetermined angle around a rotating magnetic drum that is installed outside the cassette. The present invention relates to a magnetic recording and reproducing device that records and reproduces signals by running the magnetic recording device.

Conventional Structures and Their Problems In recent years, with the remarkable spread of magnetic recording and reproducing devices, the cost of devices has been reduced rapidly. At the same time, there is a trend toward longer recording and reproducing times of devices, and greater precision than ever is required. In particular, the accuracy of the main body substrate on which the tape cassette and the magnetic drum are mounted once the tape travel path is mounted is strictly required.

Among these, the precision of the inclined mounting part of the main body board on which the rotating magnetic drum is mounted has a great influence on the playback image quality and compatibility of tape recording and playback, and the deviation and stability from the theoretical value are on the order of microns. accuracy is required.

Conventionally, magnetic recording and reproducing devices have been constructed using metal (
A die-cast molded body (for example, aluminum) is cut to ensure predetermined dimensional accuracy to form the main body substrate 2, and the upper and lower rotating magnetic drums, the TEG cassette, and the tape running path are configured on the substrate. In this method, the inclined mounting part 2-1 on which the rotating magnetic drum, which requires particularly high precision is placed, is integrated with the main body board. Accuracy of several tens of microns can be ensured during cutting. However, this method has drawbacks in terms of the cost of mass production equipment and the number of man-hours required for cutting the die-cast molded body to a predetermined size.

Figure 2 shows a metal main body board 3 (e.g. iron plate, aluminum plate).
A separate inclined mounting body 4 is installed in the main body, and is integrated with the screw 6 on the main body board. The separate inclined mounting body 4 is made of aluminum die-casting, and the parts that require precision are cut in advance. However, since this method consists of two parts, the metal main body board 3 and the tilted mounting body 4, the number of parts and assembly man-hours increase due to the double structure, and cutting of the tilted mounting body is required. It is inferior to cost competitiveness, and because of the double structure, there are problems such as disturbances in tape running stability due to deviations in the plane position of the inclined mounting part due to deviations in the setting of the reference plane, deviations in the accuracy of the height H2 inclination angle α, etc. It has its drawbacks.

FIG. 3 is intended to eliminate the drawbacks of FIG. 2 above. The inclined mounting part of the synthetic resin body is formed on a metal main body board by integrally molding the inclined mounting part with the main body of the board at the time of molding the synthetic resin body. However, high accuracy cannot be achieved due to problems with the rigidity of the synthetic resin and variations in shrinkage rate during molding. In addition, problems arise due to changes over time and linear expansion due to temperature changes, which also poses problems in terms of accuracy and stability. There are also other problems such as impact cracking due to drops, etc.

In FIG. 4, an inclined mounting portion 9-1 is constructed entirely in one piece by drawing a metal main body substrate 9.

This is an attempt to significantly improve the problem of high cost in the conventional examples shown in FIGS. 1 and 2.

However, mass production technology for drawing sheet metal with an accuracy of several tens of microns (plane position, height, angle of inclination) has not yet been achieved at present, and there are problems in ensuring accuracy.

OBJECTS OF THE INVENTION An object of the present invention is to form an inclined constriction part on a metal main body substrate, and to form a synthetic resin body integrally with the constriction part as a core when molding the synthetic resin body, thereby forming an inclined mounting part. By configuring the rotary magnetic drum directly on the above-mentioned inclined mounting part, the disadvantages of the conventional example are solved, and the main body board with high precision and good mass production can be produced stably at low cost. It is possible to reduce the cost of magnetic recording and reproducing devices.

Composition of the Invention The magnetic recording/reproducing device of the present invention has an inclined aperture part formed on a metal main body substrate, and a synthetic resin body is integrally molded with the aperture part as a core during molding of the synthetic resin body to form an inclined mounting part. By directly placing a rotating magnetic drum on the inclined mounting part, we can mass produce and supply a main body board with an integrated inclined mounting part that is highly accurate and reliable, with good mass production efficiency and at low cost. This is possible and greatly contributes to reducing the cost of magnetic recording and reproducing devices.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 6 is a schematic sectional view showing an embodiment of the present invention. Metal main body board (e.g. iron plate).

The aluminum plate) 11 has an inclined aperture 9 part 11 in advance as shown in the figure.
-1 is formed by drawing. This inclined diaphragm 9 part 11-1 does not require a high-precision slant drawing process on which a rotating magnetic drum is placed, as shown in FIG. 4 of the conventional example. (not shown), high accuracy is not required for the drawing process of the inclined portion.

This substrate main body is inserted into an injection mold, and the synthetic resin body is joined and integrated with the diaphragm 9 portion by injection molding, thereby forming the inclined mounting portion 12 of the synthetic resin body. The accuracy of the inclined mounting portion 12 can be molded regardless of the accuracy of the inclined diaphragm 9 portion 11-1 of the main body substrate 11. In other words,
When inserting and installing the board body 11 into an injection mold, the board body 11 must be positioned and installed in the mold at a preset reference plane other than the inclined diaphragm p portion 11-1 of the board body 11. 12 with dimensional accuracy from the reference plane.
It is configured so that it can be molded. In other words, regardless of the aperture precision of the inclined aperture 9 portion 11-1 of the main body substrate, it is possible to mold the inclined mounting portion 12 while ensuring the accuracy of the reference surface of the main body substrate.

In addition, as shown in the figure, since the inclined attachment part 12 is made of the entire core of the main body substrate 11, it is possible to prevent dimensional changes due to changes in the rigidity and temperature of the resin and cracks due to impact loads such as drops in the conventional example shown in Figure 3. Problems with resin bodies can be greatly improved.

As described above, it is possible to construct a main body substrate having a highly accurate and highly reliable inclined mounting portion from a sheet metal and a synthetic resin body, and mass productivity is also increased.

Effects of the Invention As is clear from the above explanation, the present invention forms an inclined constricted portion on a metal main body substrate, and when molding the synthetic resin body, integrally molds the synthetic resin body with the constricted portion as a core. By constructing an inclined mounting part and placing a rotating magnetic drum directly on the inclined mounting part, we have created a main body board with an integrated inclined mounting part that has high precision and high reliability, and is easy to mass produce. It can be mass-produced and supplied at low cost, and therefore greatly contributes to lowering the cost of magnetic recording and reproducing devices.

[Brief explanation of drawings]

1, 2, 3, and 4 are schematic sectional views of conventional magnetic recording/reproducing apparatuses, and FIG. 6 is a schematic sectional view of a magnetic recording/reproducing apparatus according to an embodiment of the present invention. 1----° one rotation magnetic drum, 2, 3, 7, 9.11
...Main board, 4...Separate inclined mounting part, 8...Synthetic resin body inclined mounting part, 9-1.
... Slanted constriction section, 11-1... Slanted constriction section, 12 ... Slanted mounting section of synthetic resin body. Name of agent: Patent attorney Toshio Nakao and one other person. Figure 1 Figure 2 Figure 3! Figure 4

Claims (1)

[Claims] A tilted constriction part is formed on a metallic main body substrate, a synthetic resin is integrally molded with the tilted constriction part as a core to constitute a tilted mounting part, and a rotating magnetic drum is directly mounted on the tilted mounting part. A magnetic recording and reproducing device.