JPH054146Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a tape reel for magnetic tape used in video tape recorders (VTR), audio, etc.

[Conventional technology]

For example, a conventional tape reel used for magnetic tape for a VTR has a reel hub 1 for winding the magnetic tape, and guide flanges 2 and 3 for guiding both edges of the magnetic tape, as shown in FIG. is formed, and this tape reel 4 is
Usually, a guide flange 2 is integrally provided at one end of the reel hub 1 to form the reel body 5, and a plurality of welding protrusions 6 are provided on the other end surface of the reel hub 1 so as to protrude from the guide flange 3 formed separately. It is constructed by welding and fixing.

[Problem that the invention attempts to solve]

However, in the above-mentioned method, the welding energy is concentrated on the welding protrusion, so that the welding protrusion may be crushed unevenly and the separate guide flange may be fixed at an angle, resulting in poor yield.

The present invention was developed against the background of the above circumstances, and an object of the present invention is to provide a tape reel that eliminates the inclination of the guide flange due to welding and improves the production rate.

[Means for solving problems]

In order to achieve the above object, the present invention has guide flanges at both ends of a reel hub around which a magnetic tape is wound, at least one of the guide flanges is formed separately, and the connection surface of the reel hub and the guide flange are formed separately. In a tape reel formed by welding and fixing the guide flange to the reel hub with the joint surface as a reference plane, welding to either the joint surface of the end of the reel hub or the joint surface of the guide flange formed separately. a recess for the reel hub and a welding protrusion longer than the depth of the recess on the other side, and welding the tip of the welding protrusion to the bottom of the welding recess to tightly bond both joint surfaces of the reel hub and the guide flange. In particular, it is preferable to provide a welding recess on the reel hub side and a welding protrusion on the guide flange side, which is formed separately from the reel hub.

〔Example〕

An embodiment in which the present invention is applied to a magnetic tape cassette for a VTR will be described below with reference to FIGS. 1 to 3.

In the magnetic tape cassette 10, supply and take-up tape reels 15, 15 for winding the magnetic tape 14 are rotatably housed in a cassette body 13 composed of an upper half 11 and a lower half 12.
At the front of the cassette main body 13, which is the VTR insertion side,
A front cover 16 is attached so as to be openable and closable, and covers the magnetic tape 14 that is unwound from the reels 15 and runs on the front surfaces of the tape guide sections 13a and 13a.

The above supply and winding tape reels 15, 15
The reel body 18, which constitutes the tape reel 15 together with the separately formed guide flange 17, is made of synthetic resin material and has the same shape.
A reel hub 20 is formed by an inner peripheral wall 20a having a fitting recess 19 with a protruding engaging rib 19a and an outer peripheral wall 20b around which the magnetic tape 14 is wound, and a guide flange 2 provided at one end of the reel hub 20.
1 has a guide edge 21a that guides the reel shaft of the VTR in the fitting recess 19, and an engagement edge 21b that is loosely fitted into the mounting hole of the cassette body 13 and protrudes from the inside and outside.

The reel hub 20 of the reel body 18 has an inner peripheral wall 2
The other end of 0a is the joint surface 22, and an appropriate number of welding holes 23 are formed on the outer circumferential side of the joint surface 22 to serve as welding recesses.
is drilled. Further, the guide flange 17 has a joint surface 24 formed in a portion corresponding to the joint surface 22, which comes into close contact with the joint surface 22 when the guide flange 17 is combined with the reel body 18,
Both joining surfaces 22 and 24 serve as reference surfaces when the guide flange 17 and the reel body 18 are combined.

The joint surface 24 of the guide flange 17 has a welding protrusion 2 that is fitted into the welding hole 23 when the guide flange 17 is combined with the reel body 18.
5 is provided protrudingly, and the length of the welding projection 25 is l ₁
is longer than the depth l ₂ of the welding hole 23.

Then, the welding protrusion 25 of the guide flange 17
When the welding protrusion 25 is inserted into the welding hole 23 and ultrasonic welding is performed, the tip of the welding protrusion 25 is melted and welded to the bottom of the welding hole 23, and there is no foreign material between the welding surfaces 22 and 24. , the tape reel 15 is constructed by the bonding surfaces 22 and 24 being in close contact with each other while maintaining their flatness.

The welding holes 23 may be integrally molded when the reel body 18 is molded. In this case, the reel body 1
8 is a protruding pin (not shown) when releasing the mold after molding.
Since the joint surface 22 is pushed by the tip of the welding pin, unevenness is caused on the joint surface 22 due to the pushing, but if the ejector pin is pushed against the bottom of the welding hole 23 to release the mold, the joint can be easily removed. Since no unevenness is generated on the surface 22 due to pressing, the surface accuracy of the joint surface 22 can be improved.

In addition, the guide flange 17 welded to the reel body 18 is guided in the mounting direction by the joining of both joint surfaces 22 and 24 at the same time as welding, so the guide flange 17 is accurately aligned parallel to the guide flange 21 on the reel body 18 side. Easy to install.

FIG. 4 shows a different embodiment in which welding holes 23 and protrusions 25 are provided on the inner periphery of both joint surfaces 22 and 24, in contrast to the above embodiment in which welding holes 23 and protrusions 25 are provided on the outer periphery of both joint surfaces 22 and 24, respectively. This is an example. In this embodiment as well, the parallelism of both guide flanges 17 and 21 can be obtained with high precision, and the number of defective products due to the inclination of the guide flanges can be greatly reduced, improving the product ratio and quality. I can do it.

Note that the welding recess of the present invention may be formed in a circumferential shape other than the hole shape of the above embodiment, and the welding recess and protrusion may be formed at each joint of the reel hub or a guide flange formed separately from the reel hub. It may be provided on any surface.

Furthermore, the present invention can be applied to a tape reel in which both guide flanges are formed separately and fixed to the reel hub by welding.

[Effect of idea]

As explained above, the tape reel of this invention has
At least one of the guide flanges at both ends of the reel hub is formed separately, and a recess for welding is formed on either the joint surface of the end of the reel hub or the joint surface of the separately formed guide flange, and the depth of the recess is deeper than that of the recess on the other side. A long welding protrusion is provided, and the tip of the welding protrusion is welded to the bottom of the welding recess to bring the joint surfaces of the reel hub and guide flange into close contact, so there is no foreign matter between the two joint surfaces, and the guide By welding the flanges while simultaneously maintaining the flatness of both joint surfaces, the parallelism of both guide flanges can be achieved with high precision.

As a result, the number of defective products can be significantly reduced, the production rate and quality can be improved, and costs can be reduced.

[Brief explanation of drawings]

Figures 1 to 3 show an embodiment of the present invention; Figure 1 is an exploded cross-sectional front view of a tape reel;
Fig. 2 is a cross-sectional front view after assembly, Fig. 3 is a partially cut-away front view of a VTR magnetic tape cassette to which the present invention is applied, and Fig. 4 is a cross-sectional front view of a tape reel showing another embodiment. FIG. 5 is a cross-sectional front view of a conventional tape reel. 10... Magnetic tape cassette, 13... Cassette body, 14... Magnetic tape, 15... Tape reel, 17... Guide flange formed separately from reel body 18, 18... Reel body, 19...
... Fitting recess, 20 ... Reel hub, 20a ... Inner peripheral wall, 20b ... Outer peripheral wall, 21 ... Reel body 1
a guide flange formed integrally with 8, 22,2;
4... Joint surface, 23... Welding hole, 25... Welding protrusion.

Claims (1)

[Scope of utility model registration request] A reel hub around which a magnetic tape is wound has guide flanges at both ends, at least one of the guide flanges is formed separately, and the guide flange is connected to the reel hub with the joint surface of the reel hub and the joint surface of the guide flange as a reference plane. In the tape reel formed by welding and fixing to the reel hub, a welding recess is formed on either the joint surface of the reel hub end or the joint surface of the separately formed guide flange,
Welding protrusions longer than the depth of the recess are provided on the other side, and the tip portions of the welding protrusions are welded to the bottom of the welding recess to bring the joint surfaces of the reel hub and the guide flange into close contact. Features a tape reel.