JPS6253331B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Object of the Invention) The present invention relates to a method for manufacturing a flanged bobbin, in which a synthetic resin flange is molded onto the end of a metal winding shaft.

An object of the present invention is to provide a flanged bobbin that has high strength in the axial direction and excellent balance performance.

(Prior Art) A bobbin in which a synthetic resin flange is molded at the end of a metal winding shaft is known. The bobbin is manufactured by the following method. The winding shaft is inserted into a mold, and molten synthetic resin material is injected into a cavity provided in the mold corresponding to the shape of the flange. The gate where synthetic resin material flows is
Provided in one or two locations not on the axis of the cavity, but offset from the axis of the cavity,
Since the synthetic resin material is injected into the cavity from one or two of the gates, a weld line is formed on the flange formed within the cavity, and a difference in density occurs due to a difference in injection pressure distribution. In the former case, the strength of the flange is significantly reduced at the weld line, and in the latter case, this causes flange deflection.

In particular, when a synthetic resin material reinforced with glass fiber or the like is used for the flange, the strength of the weld line portion is significantly reduced due to orientation.

Furthermore, in the case of water-absorbing synthetic resins, the difference in water absorption due to the difference in density immediately causes imbalance, and there is a drawback that they cannot withstand high-speed rotation. The difference in water absorption rate often changes during use of the bobbin, which has the disadvantage of causing flange runout and adversely affecting the twisted yarn.

When the twisted yarn wound around the bobbin is subjected to heat treatment, chemical treatment, etc., the above-mentioned drawbacks occur particularly markedly, so that it has been impossible to put it into practical use.

The occurrence of weld lines and differences in density has been an extremely difficult problem that cannot be easily solved by adjusting injection molding conditions.

(Structure of the Invention) In order to eliminate the above-mentioned drawbacks, the present invention provides an annular gate that communicates with a cavity formed in an annular shape on the outside of a metal winding shaft, and injects synthetic resin material radially from the gate. A cylindrical bearing body that is inserted into the metal winding shaft and serves as a bearing for a spindle of a yarn twisting machine, etc., and a cylindrical bearing body that is also inserted into the metal winding shaft and reinforced at the open end of the metal winding shaft. A cylindrical reinforcing member is molded from a synthetic resin material, and a cylindrical bearing body is inserted from the end of the metal winding shaft, and then a cylindrical reinforcing member is inserted and the cylindrical reinforcing member is molded from a synthetic resin material. The member and the flange, the cylindrical reinforcing member and the cylindrical bearing body are friction welded at the same time.

Embodiments of the present invention will be described below based on the drawings.

In FIGS. 1 to 5, the double flange bobbin 1 has a first flange 5 at the left end of a metal winding shaft 3 made of carbon steel, alloy steel, stainless steel, aluminum, aluminum alloy, etc., and a second flange 5 at the right end. The flange 7 is molded from thermoplastic synthetic resin.

Both ends of the metal winding shaft 3 are flanged to form outward flange portions 9, and through holes 11 are bored at a plurality of locations close to the flange portions 9.

The flange 5 at the left end of the winding shaft 3 is formed according to the following procedure. In Figure 2, the left end of the winding shaft 3 is
The mold 1 is charged into the mold 13 divided into two parts.
3, the winding shaft 3 is positioned. Molding mold 13
Inside the winding shaft 3, a cavity 15 corresponding to the flange 5 whose axis coincides with the axis of the winding shaft 3 is formed on the outside of the winding shaft 3, and a sprue 17 is formed so as to coincide with the axis. . A core metal 19 is inserted from the right end of the winding shaft 3, and the tip of the core metal 19 is brought close to the inner surface 21 of the molding die 13 with a predetermined gap.
A pool 23 is formed at the axial center of the tip of the core metal 19, and a gap formed between the center of the tip of the core metal 19 and the inner surface 21 of the molding die 13 becomes a runner 25, and the tip of the core metal 19 A gap formed between the outer peripheral portion and the inner surface 21 becomes the gate 27.

When the molten thermoplastic synthetic resin material is press-fitted from the sprue 17, the synthetic resin material flows into the runner 25,
It passes through the gate 27 and the through hole 11 and is injected radially toward the outer circumference, filling the cavity 15. Therefore, no weld lines occur. After a predetermined period of time has elapsed after injection molding, the synthetic resin material is cooled and the flange 5 is molded into the cavity 15.

Subsequently, when the molding die 13 is divided and the core metal 19 is removed, the flange 5 is exposed on the outside of the winding shaft 3. At this time, the synthetic resin material cooled and hardened within the sprue 17, runner 25, and gate 27 remains connected to the flange 5 through the through hole 11, so it is cut off at the boundary between the gate 27 portion and the flange 5 in a subsequent process.

Next, the flange 7 at the right end of the winding shaft 3 is formed according to the following procedure. In FIG. 3, the right end of the winding shaft 3 is inserted into the two-split molding die 29, and the winding shaft 3 is positioned with respect to the molding die 29. Inside the molding die 29, there is a cavity 3 corresponding to the flange 7 whose axis is aligned with the axis of the winding shaft 3.
1 is formed on the outside of the winding shaft 3, and a cylindrical bearing body 3 is formed on the inside of the winding shaft 3, which serves as a bearing part for a spindle of a yarn twisting machine, etc.
A cavity 35 forming a part of the shaft 3 is formed, and a sprue 37 is provided in alignment with the axis.
Insert the core metal 39 from the left end of the winding shaft 3, and
9 is brought close to the inner surface 41 of the molding die 29 at a predetermined distance. A cavity 43 corresponding to the shape of the cylindrical bearing body 33 molded inside the winding shaft 3 and connected to the cavity 35 is formed at the tip of the core bar 39, and a synthetic resin is formed at the tip axis of the core bar 39. A pool 45 of material is recessed. Core metal 39
The gap 47 where the tip of the mold 29 is close to the inner surface 41 of the molding die 29 serves as a gate, and 49 serves as a runner.
A bearing bush 51 is attached in advance to the tip of the core metal 39, and the cylindrical bearing body 33 is molded in this state. This bearing bush 51 has a bush 55 inside a metal shell 53 that has excellent wear resistance and a small coefficient of friction.

When the molten thermoplastic synthetic resin material is press-fitted from the sprue 37, the synthetic resin material passes through the runner 49 and the gate 47, is injected radially toward the outer circumference, fills the cavities 35 and 43 inside the winding shaft 3, and is further transparent. It flows into the cavity 31 on the outside of the winding shaft 3 through the hole 11, flows radially toward the outer circumference, and fills the cavity 31. Therefore, no weld lines occur. After a predetermined period of time has elapsed after injection molding, the cylindrical bearing body 33 is integrally molded within the cavities 35 and 43, and the flange 7 is integrally molded within the cavity 31.

Subsequently, when the molding die 29 is divided and the core metal 39 is removed, the cylindrical bearing body 33 is exposed inside the right end of the winding shaft 3, and the flange 7 is exposed outside.
At this time, the sprue 37, runner 33 and gate 3
Since the synthetic resin material cooled and hardened in the gate 47 remains integrally connected to the cylindrical bearing body 33, the synthetic resin material cooled and hardened in the gate 47 is cut at the boundary with the cylindrical bearing body 33 in the subsequent process. drop

A cylindrical bearing body 57 into which a bearing bushing 51 identical to the bearing bushing 51 described above is inserted is attached to the winding shaft 3.
It is molded from thermoplastic synthetic resin so that it can be inserted into the winding shaft 3, and is press-fitted into the inside of the winding shaft 3, which has the flanges 5 and 7 molded on the left and right ends as described above, as shown in FIG. A tapered joint surface 59 is provided on the left end inner circumference of the cylindrical bearing body 57, and the inner diameter increases toward the open end. Since the joining surface 61 is formed in a tapered shape such that the joint surface becomes large, a cylindrical reinforcing member 67 having tapered joining surfaces 63 and 65 in close contact with the joining surfaces 59 and 61 on the outer periphery is made of thermoplastic material. The cylindrical reinforcing member 67, which is molded from resin, is inserted into the flange 5 and the cylindrical bearing body 57. Friction welding is performed while pressing the cylindrical reinforcing member 67 against the flange 5 and the cylindrical bearing body 57. This friction welding is performed while rotating either the cylindrical reinforcing member 67 or the winding shaft 3, or both. A double flange bobbin 1 in which the flange 5, the cylindrical bearing body 57, and the cylindrical reinforcing member 67 are integrated is obtained by friction welding.

Next, a single flange bobbin 71 shown in FIG. 6 is also manufactured in the same manner as the bobbin 1 described above. That is, a metal winding shaft 77 has a flange portion 73 and a through hole 75 at both ends.
After forming a flange 79 on the outer periphery of the left end of the winding shaft 7
A flange 81 and a cylindrical bearing body 83 are molded on the right end of the winding shaft 77, and a cylindrical bearing body 85 previously molded from thermoplastic synthetic resin is inserted and press-fitted into the left end of the winding shaft 77, and further molded in advance from thermoplastic synthetic resin. cylindrical reinforcing member 8
7 and perform friction welding. A tapered joint surface 89 is formed on the inner periphery of the cylindrical bearing body 85, and the inner diameter becomes larger toward the open end.A tapered joint surface 91 is formed on the inner periphery of the flange 79, and the inner diameter becomes larger toward the open end. A joint surface 93 corresponding to the joint surface 89 and a joint surface 95 corresponding to the joint surface 91 are formed on the outer periphery of the cylindrical reinforcing member 87.
9 and the joint surface 95, and the joint surface 91 and the joint surface 93 are friction welded, respectively.

In addition, the through holes 11, 75 formed in the winding shafts 3, 77
is not limited to the illustrated oval shape, but may be formed into a polygonal shape as well as a triangular or rectangular shape.

(Effects of the Invention) Since the present invention has the above configuration, it has the following advantages.

Since the molten synthetic resin material is injection molded from the axis of the winding shaft to the concentric cavity, weld lines, which were unavoidable in conventional injection molding, are eliminated. At the same distance from the axis, the orientation density of the synthetic resin material during injection molding is uniform, and flange runout, unbalance, etc. do not occur. Therefore, the roundness is high and the strength is improved, and stable rotation with high balance performance at high speed rotation can be obtained. As a result, it is possible to provide resource-saving bobbins that do not cause uneven yarn twisting, reduce power consumption, and allow for large packages.In addition, it is possible to perform heat treatment, chemical treatment, etc. while the yarn is wound around the bobbin. It has the great effect of making it possible.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of both flange bobbins obtained by implementing the present invention, FIGS. 2 to 5 are sectional views of the main parts showing the implementation procedure of the present invention, and FIG. 6 is a front sectional view of both flange bobbins obtained by implementing the present invention. It is a front sectional view of the single flange bobbin obtained by. (Explanation of symbols of main parts) 1, 71... Bobbin, 3, 77... Winding shaft, 5, 7, 81... Flange,
9, 73...Flange part, 33, 57, 83, 85
... Cylindrical bearing body, 67, 95 ... Cylindrical reinforcement material, 59,
61, 63, 65, 89, 91, 93, 95... joint surface.

Claims (1)

[Claims] 1. A method for manufacturing a bobbin having a synthetic resin flange at the end of a metal winding shaft, the winding shaft being inserted into a mold provided with a sprue aligned with the axis of the winding shaft. , a thermoplastic synthetic resin material is injected radially from the sprue toward the outer circumference to form a flange, and then a cylindrical bearing body made of thermoplastic resin is inserted into the winding shaft, and then a cylindrical bearing body made of thermoplastic resin is inserted into the winding shaft. A method for manufacturing a flanged bobbin, comprising inserting a reinforcing material and friction-welding the cylindrical reinforcing material to the flange and the cylindrical bearing body. 2. A tapered joint surface is formed on the inner periphery of the flange so that the inner diameter increases toward the open end, and a tapered joint surface that increases in inner diameter toward the open end is formed on the inner periphery of the cylindrical bearing body. A joint surface corresponding to the joint surface of the inner periphery of the flange and the joint surface of the cylindrical bearing body is formed on the outer periphery of the reinforcing member, and the joint surface of the outer periphery of the cylindrical reinforcing member is formed between the joint surface of the inner periphery of the flange and the joint surface of the cylindrical bearing body. 2. The method for manufacturing a flanged bobbin according to claim 1, wherein the flanged bobbin is friction-fused by contact pressure with the peripheral joint surface.