JP2000173229A - Tape reel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the deflection of a tape by improving the welding accuracy of a hub and a flange and lessening flange deflection at the time of rotation. SOLUTION: The tape reel is separately provided with positioning portions 6, 7 of a cylindrical hub 2 to be wound with the tape on its outer peripheral surface 2a and a disk-shaped flange 4 and welding portions 8 and 9 for welding both via a welding rib 8a in welding the flange 4 to the end of the hub 2 and is constituted by welding the welding portions 8 and 9 in the state of pressing the positioning portions 6, 7 thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape reel having a disc-shaped flange fixed to an end of a cylindrical hub around which a tape is wound around an outer peripheral surface.

[0002]

2. Description of the Related Art There is a magnetic tape as a recording medium used for an external storage device such as a computer and other recording / reproducing devices. The magnetic tape is wound around a tape reel, loaded into the recording / reproducing device, and rotated by the tape reel. As a result, the magnetic tape travels, and recording and reproduction are performed on the recording surface.

[0003] The tape reel comprises a cylindrical hub for winding the tape around the outer peripheral surface thereof, and flanges extending in a disk shape from both ends of the hub and located on both side surfaces of the wound tape. . Generally, when this tape reel is formed of a resin molded product, one flange and a hub are integrally formed, and the other flange separately formed is fixed to an end of the hub.

[0004] The fixing of the hub to the flange is usually performed by ultrasonic welding provided with a welding boss or a welding rib (energy director). This ultrasonic welding has a short working time and a low running cost in that a part of a molded product melted is used as a bonding agent, and is widely used in the production of tape reels.

[0005]

However, in the conventional method of fixing a tape reel by ultrasonic welding via a welding rib, it is difficult to secure sufficient fixing accuracy with respect to improvement in recording density and recording accuracy. is there. In other words, when the recording density is increased, the deflection in the width direction of the tape affects the recording / reproducing characteristics, and the precision of the running height of the tape is more strictly required. With ultrasonic welding, it is extremely difficult to weld the flange with high accuracy at right angles to the rotation axis, and the development of high-precision reels that can sufficiently respond to the high-density recording demanded in recent years is urgent. Is peeling.

More specifically, FIG. 7 shows a conventional tape reel having welding ribs formed thereon. A cylindrical hub 52 around which a magnetic tape is wound around the outer peripheral surface
An annular flat fixing portion 60 is formed on the end surface near the outer peripheral surface of the outer peripheral surface. On the other hand, a welding rib 61 having a substantially triangular cross section is annularly protruded from the flange surface on the inner peripheral portion of the disk-shaped flange 54. (See FIG. 7A). Then, the flange 54 is placed on the hub 52, and the flange 54 above the welding rib 61 is formed from above by the annular tip surface of the welding horn.
7A and 7B, the welding rib 61 is melted and fixed to the hub 52 as shown in FIG.

However, in the fixing by the welding rib 61 as described above, the height position of the flange 54 in the rotation axis direction of the hub 52 is also determined at the welding portion, so that sufficient dimensional accuracy can be obtained. Have no problem. That is, the position in the height direction of the flange 54 changes depending on the degree of welding (the degree of melting of the welding rib 61), and the height of the flange 54 decreases in a portion where the melting of the welding rib 61 is large, and the melting of the welding rib 61 decreases. In a small portion, the height of the flange 54 is high. Then, it is difficult to uniformly weld the welding rib 61 in a predetermined molten state all around the flange 54,
If the melting degree of the welding rib 61 is different, the flange 54 tilts, and a run-out occurs during rotation. Further, since the ultrasonic energy is concentrated and melted on the welding rib 61 without directly contacting the welding horn with the welding rib 61, the design of the welding rib 61 for melting in an appropriate state and the conditions of the ultrasonic welding are performed. Setting is complicated and difficult.

Further, when an external force is applied to the welded flange 54 in a direction in which the flange 54 is peeled off, the flange 5
Since the flexure of No. 4 acts directly on the welded portion to facilitate peeling, the welding rib 60 must be provided large and vibrated with high ultrasonic energy in order to increase the welding force.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a tape reel which has improved welding accuracy between a hub and a flange and has less runout of tape.

[0010]

According to a tape reel of the present invention which solves the above-mentioned problems, a disk-shaped flange is welded to an end of a cylindrical hub around which a tape is wound around an outer peripheral surface.
The positioning portion of the hub and the flange is separated from a welding portion to be welded via a welding rib, and the welding portion is welded in a state where the positioning portion is in contact with the welding portion.

More specifically, the hub has a positioning portion or a welding portion on an end face, and has a welding portion or a positioning portion at a tip end of a low-height reinforcing rib provided on an inner peripheral surface, while the flange has a flange. It is preferable that a positioning portion or a welding portion is provided on a flange end surface abutting on an end surface of the hub, and a welding portion or a positioning portion is provided on an end surface of a boss portion extending in the rotation axis direction on an inner peripheral portion and abutting on a tip of the reinforcing rib. It is.

At this time, a welding rib extending in the radial direction is provided at the welding portion of the hub or the welding portion of the flange, or a welding rib extending in the radial direction is provided at the welding portion of the hub, and the welding portion of the flange is circular. Preferably, a circumferentially extending welding rib is provided.

The hub may have a positioning portion and a welding portion provided separately on an end face thereof, while the flange may have a positioning portion and a welding portion provided separately on an end face of the flange abutting on the end surface of the hub. .

[0014]

According to the present invention as described above, the positioning portion of the hub and the flange and the welding portion to be welded through the welding rib are provided separately, and the welding portion is welded with the positioning portion in contact. As a result, the requirements for the uniformity of the welding degree are relaxed, the welding conditions can be easily set and the productivity is excellent, and the flange is deformed at right angles to the rotation axis by securing the positioning at the positioning part. Good dimensional accuracy can be obtained by fixing the tape in a non-existent state, the run-out in the width direction of the wound tape can be reduced, and the recording density and the recording accuracy can be sufficiently improved. Thus, the welding strength can be secured by the reliable welding, and a large peel strength against the external force of the flange can be obtained.

A positioning portion is provided on the end surface of the hub, and a welding portion is provided on a tip portion of the reinforcing rib having a low inner peripheral surface, while a positioning portion is provided on the flange end surface, and a welding portion is provided on the boss end surface. And, by securing a large positioning surface, surface runout accuracy can be improved with good positioning without being greatly affected by the manner of welding, and welding strength against bending deformation of the flange can be ensured by the fact that the welded portion is in the middle inside .

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. FIG. 1 is a sectional view of a tape reel according to one embodiment, and FIG. 2 is an enlarged view of a main part.

The tape reel 1 has a magnetic tape having an outer peripheral surface 2.
The cylindrical hub 2 wound around a and a flange portion 3 which protrudes radially in a disk shape from the outer periphery of one end (the lower side in the figure) of the hub 2 are integrally formed of synthetic resin. A disc-shaped flange 4 formed separately from a synthetic resin is fixed to the other end of the hub 2 by welding.

An inner wall 11 is connected to an inner peripheral portion of the hub 2 so as to close an inner peripheral portion of the disk-shaped flange portion 3. An outer surface of the inner wall 11 is used for driving the tape reel 1 to rotate. The reel gear 12 is engraved in an annular shape, and a plate 13 made of an annular metal plate for magnetic attraction is inserted into the inner side of the reel gear 12 during molding.

A plate-like reinforcing rib 10 extending upward from the inner wall 11 is radially connected to the inner peripheral surface 2b of the hub 2 at substantially equal intervals in the circumferential direction.
Thus, the cylindricity of the hub 2 is maintained. The height of the reinforcing rib 10 is formed at a position lower by a predetermined amount than the height of the hub 2 by the height of a boss 5 of the flange 4 described later.

As shown in FIG. 2, a stepped positioning portion 6 is formed on the end surface of the hub 2 to which the flange 4 is fixed, so as to have a lower portion on the inner peripheral surface 2b side.
Is provided, and an end surface of the positioning portion 6 orthogonal to the rotation axis S is a positioning surface. As shown in FIG. 3, a welding rib 8 extending in a radial direction is provided on an upper end of the reinforcing rib 10.
a is provided on the welded portion 8. The welding rib 8a has a substantially triangular cross section, and its dimensional shape is appropriately designed according to the size of the tape reel 1 and the like.

On the other hand, the flange 4 has a circular opening at the center, and a boss 5 projecting in a direction perpendicular to the flange surface 4a is formed on the periphery of the opening, as shown in FIG. At the joint corner between the boss 5 and the flange surface 4a,
An annular convex positioning portion 7 that fits into the step-shaped positioning portion 6 of the hub 2 is formed. Then, an end surface of the flange 4 parallel to the flange surface 4a of the positioning portion 7 becomes a positioning surface. Further, an annular lower end surface of the boss portion 5 is formed in the welding portion 9.

To weld the hub 2 and the flange 4, the boss 5 of the flange 4 is inserted into the inner peripheral surface 2 b of the hub 2, and the weld 9 at the tip of the boss 5 is attached to the weld 8 of the hub 2. At the same time, it comes into contact with the tip of the welding rib 8a, and the positioning part 7 of the flange 4 is fitted and assembled with the positioning part 6 of the hub 2. In the assembled state before welding, the positioning end surface of the positioning portion 7 of the flange 4 and the positioning end surface of the positioning portion 6 of the hub 2 are separated by the fusion height (welding margin) of the welding rib 8a of the welding portion 8. I have.

Then, ultrasonic vibration is applied while pressing the flange 4 (boss portion 5) near the upper side of the welding rib 8a with the annular tip surface of the welding horn from above, so that the welding rib 8a is melted and The welding portion 9 and the welding portion 8 of the hub 2 are welded, and the positioning portion 7 of the flange 4 and the positioning portion 6 of the hub 6 come into contact with each other as the height of the welding rib 8a decreases due to the melting of the welding rib 8a. The welding is completed in the positioning state.

According to the present embodiment, the positioning portion 6 is provided on the end surface of the hub 2, and the positioning portion 7 is provided on the corresponding end surface of the flange 4, while the welding portion 8 is provided on the tip of the reinforcing rib 10 of the hub 2. The welding portion 9 is provided on the end face of the boss portion 5 of the flange 4 corresponding to this, and the positioning portion and the welding portion are separated from each other. The surface runout accuracy can be improved with good positioning, and the welding strength against bending deformation of the flange 4 is increased because the welding portions 8 and 9 are located in the middle portion in the hub. In addition, the melting height of the welding rib 8a is finally determined in a positioned state, so that the flange 4
The tape reel 1 after fixing can be formed with the dimensional accuracy corresponding to the molding accuracy without causing deformation of the fixing of the hub 4, and the flange 4 is fixed to the rotation axis S of the hub 2. When the tape reel 1 is rotated to feed or wind the magnetic tape, the flange 4
, The fluctuation of the running magnetic tape in the width direction is small and the positional accuracy is good, the influence on the recording / reproducing characteristics is small, and it is possible to cope with high density.

In the above embodiment, the welding rib 8a
Is formed at the end of the reinforcing rib 10 of the hub 2, but a welding rib extending in the radial direction is provided at a position corresponding to the reinforcing rib 10 of the hub 2 on the end welding portion 9 side of the boss 5 of the flange 4. Similarly, welding may be performed.

FIG. 4 shows another embodiment.
The welding ribs are provided on both sides of the welding portion, and other positioning portions 6, 7 and the like are provided in the same manner as in FIGS.

The welding portion 8 at the tip of the reinforcing rib 10 of the hub 2 has a welding rib 8a extending in the radial direction as shown in FIG.
Further, an annular welding rib 9a extending in the circumferential direction is provided on the annular welding portion 9 at the lower end of the boss portion 5 of the flange 4. The welding of the welding portions 8 and 9 is performed in a point-like manner at the intersection of the tips of the welding ribs 8a and 9a.

According to this embodiment, the hub 2 and the flange 4
The welding ribs 8a,
9a is formed and welded in a point-like manner at the intersection thereof, whereby a sufficient melting height can be secured, and some of the welding ribs 8a,
It is possible to prevent the welding from being performed in a state where the positioning portions 6 and 7 of the hub 2 and the flange 4 are not in contact with each other due to insufficient melting of 9a, so that welding can be performed uniformly over the entire circumference.

FIG. 5 shows still another embodiment, in which positioning portions 16 and 17 are provided on the inner peripheral side and welded portions 18 and 19 are provided on the outer peripheral side. It is provided similarly to.

That is, on the end face of the hub 2 to which the flange 4 is fixed, there is provided a stepped welded portion 18 which is annularly concave so that the portion on the inner peripheral surface 2b side is lowered. An upper end surface of the rib 10 is formed on the positioning portion 16. On the other hand, the flange 4 is formed with an annular convex welding portion 19 that fits into the step-like welding portion 18 of the hub 2,
A welding rib 19 extending in the circumferential direction is provided on an end face of the welding portion 19.
a is provided, and an annular lower end surface of the boss portion 5 is formed on the positioning portion 17.

In the assembled state before welding, the positioning portion 17 of the flange 4 and the positioning portion 16 of the hub 2 are separated by the fusion height of the welding rib 19a of the welding portion 19, and the welding horn When ultrasonic vibration is applied while pressing at the distal end surface, the welding ribs 19a are melted and both welding portions 1 are welded.
8 and 19 are welded and the positioning portions 16 and 17 come into contact with each other, and the welding is completed in this positioning state.

The welding ribs 19a may be provided on the welding portion 18 side of the hub 2 or may be formed in the radial direction, and are formed so as to intersect both the welding portions 18 and 19. You may.

FIG. 6 shows another embodiment, in which positioning portions 26 and 27 and welding portions 28 and 29 are provided on an annular end face portion so as to be separated in the circumferential direction. .

That is, an annular step is formed on the end surface of the hub 2 to which the flange 4 is fixed, so that the portion on the inner peripheral surface 2b side is lowered. And a welding portion 28 are provided, and the welding portion 28 is formed in a concave shape lower than the positioning portion 26. This welding portion 28
Are formed at substantially equal intervals in the circumferential direction of the hub 2.
On the other hand, the flange 4 is formed with an annular convex shape that fits into the step of the hub 2, and the convex portion is provided with a positioning portion 27 and a welding portion 29 alternately in the circumferential direction. It is formed in a convex shape higher than the portion 27 and can be fitted to the welding portion 28 of the hub 2. A welding rib 29a extending in the circumferential direction is provided on an end face of the welding portion 29.

Then, the boss portion 5 of the flange 4 is inserted into the inner peripheral surface 2b of the hub 2, and the welded portion 29 is assembled so as to fit in a circumferential position with the welded portion 28 of the hub 2, and is welded. When ultrasonic vibration is applied while pressing with the tip of the horn, the welding rib 29a is melted to weld the welding portions 28 and 29, and the positioning portions 26 and 27 come into contact with each other. In this positioning state, welding is completed.

The welding rib 29a may be provided on the welding portion 28 side of the hub 2 or may be formed in the radial direction, and is formed so as to intersect both the welding portions 28 and 29. You may. Further, the reinforcing rib 10 as described above may be formed on the inner peripheral surface 2b of the hub 2.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a tape reel according to one embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG. 1;

FIG. 3 is an enlarged perspective view of a welded end of a reinforcing rib of FIG. 1;

FIG. 4 is an essential part cross-sectional view showing a state before welding of a tape reel according to another embodiment.

FIG. 5 is an essential part cross-sectional view showing a state before welding of a tape reel according to still another embodiment.

FIG. 6 is a partial perspective view showing a tape reel according to another embodiment in a state before welding, which is partially welded;

FIG. 7 is a sectional view showing a main part of a conventional tape reel welding structure before and after welding.

[Explanation of symbols]

 1 Tape reel 2 Hub 2a Outer surface 2b Inner surface 3 Flange part 4 Flange 4a Flange surface 5 Boss part 6,7,16,17,26,27 Positioning part 8,9,18,19,28,29 Welding part 8a , 9a, 19a, 29a Welding rib 10 Reinforcing rib S Rotating shaft

Claims (3)

[Claims] 1. A tape reel in which a disc-shaped flange is welded to an end of a cylindrical hub around which a tape is wound around an outer peripheral surface, wherein the hub and the flange are welded via a welding rib and a welding rib. A tape reel characterized in that a welding part is provided separately from a welding part to be welded, and the welding part is welded in a state where the positioning part is in contact with the tape reel. 2. The hub has a positioning portion or a welding portion on an end face, and has a welding portion or a positioning portion at a tip portion of a low-height reinforcing rib provided on an inner peripheral surface, while the flange is provided on the hub. A flange or a welded portion is provided on an end surface of the flange abutting on the end surface, and a welded or positioned portion is provided on an end surface of a boss extending in the rotation axis direction on the inner peripheral portion and abutting on a tip of the reinforcing rib. Item 2. A tape reel according to Item 1. 3. The positioning means and the welding part are provided separately on the end face of the hub, and the positioning part and the welding part are provided separately on the flange end face abutting on the end face of the hub. The tape reel according to claim 1, wherein: