JPS60246072A - Tape reel and its production - Google Patents

Abstract

PURPOSE:To obtain a light-weight tape reel with low cost by providing equidistantly plural pieced holes which are tapered toward the outer surface from the inner surface of flange of a reel main body, and reducing the heat shrinkage and improving the molding accuracy. CONSTITUTION:The outer surface of a hub 2 of a reel main body 1, an inner surface 6a of a flange 6, a pierced hole 16 and a molding projection 18 are formed with a female metallic mold 8. While a hub hole 3, a hub pawl 4 and a flange outer surface 6b are formed with a male metallic mold 9. Thus the main body 1 is formed. The flange 6 has plural pierced holes 16 formed equidistantly, therefore the thickness of the flange 6 is reduced in its diameter direction T. In such a way, the effect of the heat shrinkage to the hub outer circumferential surface 12 is reduced, and the surface 12 can have a real circular shape. In addition, no flash is produced inside the reel sine the mold matching is carried out at the outside 6a of the flange 6. Then the weight of the reel is reduced to eliminate the function of the force of inertia and also to reduce the cost.

Description

[Detailed description of the invention] (a) Purpose of the invention (industrial application field)
This article concerns the synthetic resin tape reel built into the cassette case of a recorder and its molding method.The tape winding involves molding the outer peripheral side of the hub, which is the surface, into a more perfect circle, and making it more cost-effective. The purpose is to form.

(Prior art) A tape reel is built inside a cassette case so that it can rotate left and right, and consists mainly of a synthetic resin reel body with a flange on one side of the hub, and a separate resin flange that is ultrasonically welded on the other side of the hub. A hub hole opening in the axial direction is provided in the center of the hub, hub claws are protruded at equal intervals on the inner circumferential surface of the hub hole, and clamp holes are provided at points on the outer circumferential side of the hub. A clamp piece is fitted and locked into the clamp hole, the end of the tape is fixed with the piece fitted into the clamp hole, and the magnetic tape is wound around the outer periphery of the hub. And Chi 7°
The reel is stable in winding and unwinding the magnetic tape and in running, and does not adversely affect the electromagnetic conversion characteristics, and after the start operation,
It is considered best if the time it takes to reach a predetermined speed and the time it takes to come to a complete stop after a stop operation is short. However, when a reel body with uneven wall thickness in the radial direction was molded in one batch, a heat shrinkage change occurred on the outward side surface of the hub around which the tape was wound, that is, a sink mark adversely affected the tape. As a means to reduce the occurrence of sink marks, attempts have been made to mold with synthetic resins that have less heat shrinkage.

(Problems to be Solved by the Invention) Even if the reel body is molded from a synthetic resin with low heat shrinkage, the occurrence of sink marks cannot be completely prevented. , becomes heavier and the inertia increases,
There were problems such as reduced speed of starting and stopping.

(B) Structure of the Invention (Means for Solving Problems) Therefore, the present invention provides at least one through hole at equal intervals in the flange of the main reel, thereby making the tape reel light and inexpensive. In addition, by forming the through holes, thermal shrinkage can be reduced, and the molding accuracy of the outer peripheral side surface of the pub can be improved.

(Example) Next, the structure of the reel of the present invention and its molding method will be explained with reference to the drawings of the example.
) The reel body (1) has a flange (6) integrally molded on one end of the hub (2) with the molded side of the flange (6) facing down.
) A drive shaft insertion hub hole (3) that opens downward in the center of the
and several hub claws (4) on the inner peripheral surface of the no-pu hole (3).
are provided protrudingly at equal intervals, and a clamp hole (5) that opens toward the outer circumference is provided in the axial direction at one location on the outer peripheral side surface (2) of the hub above the flange (6), and the molded side of the flange (6) and The point that several protrusions (protrusions) are provided upwardly at the center of the opposite hub end surface (2) and its surface is basically the same as the conventional reel body, but in the case of the present invention, the reel The flange (6) of the main body (1) has a unique design as described below.

Immediately, the inner surface (6) is attached to the flange (6) of the reel body (1).
At least one Taper through hole α that tapers slightly toward the outer surface (6/l) is drilled in a balanced manner, or an annular edge (6C) is formed at the outer peripheral end of the flange outer surface (6/l). established,
In addition to forming square teeth (E) up to 60 on the edge (60), reinforcing ribs (6 frames) formed on the flange (6) with a part thereof protruding outward are arranged in several rows at equal intervals in the radial direction from the inner circumference. established,
A through hole OQ that tapers toward the outer surface (6/) is bored in the flange between the 6ψ and the rib (6 frame. Also, in the protrusion of the reel body +1) It is not necessarily necessary to provide a through hole (17) in the separate flange (7) attached to the hub end face (2→) provided with a through hole (η), but if a through hole (η is provided), From the outer surface (7
It is provided so that it tapers slightly toward zero.

Furthermore, the parting line of the male parallel mold (9) and female mold (8) for molding the reel body (1) of the present invention is located on the outer surface of the flange (
6/l or at a position that coincides with the outer surface of the flange edge (6C). ), then mold the hub hole (3), hub pawl (4), and flange outer surface (6/l) using the male mold (9), and mold the female mold (8).
The flange x hole forming protrusion O! G is provided, and this protrusion O fathom is made to be slightly tapered, so that the gaps in the molds (8) and (9) that cause the formation of gaps are removed from the reel body (1
) to prevent the formation of cracks on the inside of the reel body (1) on which the magnetic tape is wound. The inner surface of the flange (
Example 1 of the outer periphery of the hub (2) that protrudes vertically from 6ψ (2)
However, it is possible to form a more perfect circle with the same diameter from the base diameter (D) to the tip diameter to). In addition, the flange (6
) is not limited to a circular shape, but may be formed into an aesthetic fan shape, a rectangular corner with rounded corners, an arc shape, etc. to achieve the same purpose.

(Function) The reel base price (]) constituting the tape reel of the present invention is:
Since the flange (6) is provided with a plurality of through holes α, the radial wall thickness h) at the flange forming portion is thinner than that without the through holes a→, and the heat is reduced accordingly. The effect of shrinkage is reduced, especially on the outer peripheral side of the hub (
b) The impact on the base is halved. Further, by forming the through hole 0[9, the amount of material can be reduced accordingly, and the weight can be reduced accordingly. Furthermore, the mold for the reel body (1) (
8) In (9), the mold is matched on the outside of the flange (6) that is integrally molded on one end of the hub (2), so the tape end side of the reel base (1), that is, the inside of the reel base (1). Paris will never arise.

(c) Effects of the Invention Therefore, in the tape reel and the method for forming the same of the present invention, since the through-hole is provided in the flange of the main reel, the wall thickness in the radial direction at the flange forming part is thinned by the amount of the through-hole. As a result, the effect of heat shrinkage on the outer peripheral side surface of the hub is reduced by the amount of thinner wall. As a result, not only can the outer circumferential side of the hub be made more perfectly circular and more vertical than the flange, but by providing multiple through holes in the flange, the molding material for the reel can be saved accordingly, and the reel can be It is possible to reduce the weight and reduce the effect of inertial force. In addition, the parting line of the mold for forming the reel body is provided on the non-tape winding side that coincides with the outer surface of the flange, so that the molds can be matched on the non-tape winding side. The generated flash does not occur on the tape winding side of the inner surface of the flange. Moreover, even if a through hole is provided in the flange, it will not have a negative effect on the winding of the magnetic tape and will not make it difficult to form the reel body, so the present invention has a practical effect on improving the performance of tape reels. It is effective.

[Brief explanation of drawings]

Fig. 1 is a front view of the Q-pleel of the present invention, Fig. 2 is an exploded longitudinal sectional view thereof, Fig. 3 is a similar sectional view of a separate flange, Fig. 4 is a plan view thereof, and Figs. 5 to 7. is a plan view of a similar example of the reel body, FIGS. 8 to 10 are longitudinal sectional views thereof, and FIG.
13 are bottom views, FIG. 14 is a partially cutaway front view of the main reel, and FIG. 15 is a cross-sectional view of essential parts showing an example of the structure of the reel main stop molding. (1)...Reel body, (2)...Hub, (2(L)
・Hub end face, α bulge…outer periphery side, (Foundation)…protrusion, (
3)...Hub hole, (4)...Hub pawl, (5)...Clamp hole, (6)...Flange, (6→...Inner surface, (6/l)
・・Outer surface, (6C)・・Edge, (6 frames・・Rep, αQ・
・Through hole, (E)... Radial tooth, (7)...Separate flange, (8)...Female mold, θ line...Protrusion, (9)...Male die, (Tl... The radial thickness of the reel base, tc+...Hub tip diameter, fDl...Hub base diameter, 019...Clamp piece

Claims (1)

[Claims] 1) A tape reel consisting of a reel base (1) having a flange (6) integrally molded on one end of the hub (2), and a separate flange (7) attached to the other end of the hub. In,
A tape reel in which at least one through hole OQ is provided in the flange (6) of the reel body (1). 2) Flange (6) of single flange type reel body (1)
K, In order to drill a plurality of through holes QQ that taper toward the inner surface (6 → outer surface (6/l) in a well-balanced manner, the molds (8) and (9) for forming the reel main body are wound around the flange. The molds are matched on the take-up side to prevent the occurrence of cracks on the tape take-up side, while the through holes provided in the flange reduce the radial wall thickness (Tl) at the flange forming part and reduce the hub outer circumferential side (2). In addition to reducing the effect of heat shrinkage on
A method for forming a tape reel, which is characterized by making it possible to reduce the flfj and weight of the material.