JPS62189150A - Manufacture of tape reel - Google Patents

Abstract

PURPOSE:To reduce internal strain, improve molding accuracy as well as workability and secure the good function of a spring receiver by a method wherein the position of a gate for pouring resin is set at the tip end part of a spring receiving boss and injection molding is performed, thereafter, the spring receiving boss is melted by heat and the trace of the gate is eliminated to reform smooth. CONSTITUTION:The position of a spring receiving boss 6, provided at the center of the outer surface of the axial one end of a cylindrical section 2 of a reel is set at a gate G. After molding the cylindrical section 2 of the reel, the spring receiving boss 6 is melted by heat to eliminate and reform the trace (a) of the gate smoothly. Here, a supersonic horn 18, having a recess 19 coinciding with the predetermined configuration of the sumit of the spring receiving boss 6, is employed as a means to eliminate and reform the trace (a) of the gate smooth by thermal fusion so as to be capable of generating heat in a very short period of time and effecting the melting and reforming works efficiently. On the other hand, in case a fusion welding pin 7 is projectedon an end surface having the spring receiving boss 6 of the cylindrical section 2 of the reel and is bonded to an upper flange 3 through caulking and fusion welding, the same supersonic horn 18 or a hot plate is employed for both works so that the caulking and fusion welding works of the fusion weldin pin 7 can be effected simultaneously with the eliminating and reforming works of the trace of the gate for the boss 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a plastic tape reel built into a tape cartridge.

[Conventional technology]

FIG. 4 illustrates a conventional tape cartridge with a built-in tape reel, and the tape reel 1 is composed of a reel body 2 with a lower flange and an upper flange 3 integrally connected to the reel body 2. The lower flange-equipped reel body 2 is formed into a double cylindrical shape having a drive shaft hole 4 with an open bottom, and is formed in such a manner that the upper end of the drive shaft hole 4 is closed with an upper end wall 5. A spring receiving boss 6 is integrally protruded from the center of the upper surface side, a plurality of welding pins 7 are integrally protruded around the spring receiving boss 6, and a lower flange 8 is integrally protruded from the outer periphery of the lower end of the reel body 2. It is formed into. On the other hand, the upper flange 3 is formed into a flat plate shape having a center hole 9 and a coupling hole 10 in which the spring receiving boss 6 and welding pin 7 are inserted. Thus, the upper flange 3
The center part of the welding pin 7 is placed on the upper surface of the upper end wall 5 of the reel body 2, the spring receiving boss 6 and the welding pin 7 are inserted into the holes 9 and 10, and the end of the welding pin 7 protruding from the hole 10 is heated. By crushing the J-flange 3, the J-flange 3 is integrally caulked and welded to the reel body 2.

Then, this tape reel 1 is rotatably inserted into the main body case 1) of the tape cartridge, but at this time, the spring receiving boss 6 is held by the reel holding plate spring 12 attached to the inner side of the main body case 1). Being pressed down, the tape reel 1 is regulated so that it does not unintentionally wobble in the thrust I direction within the main body case 1).

By the way, when injection molding the reel body 2 having the above shape from a plastic material, care is taken to ensure that no deformation or internal distortion remains in the reel body 2, which is a molded product.

In addition, it is necessary to pay attention to the gate position for resin injection in consideration of spoiling the appearance, etc., but in general.

As shown in FIG. 5, the gate G is set at the receiving pin 7 or at the center of the inner surface of the upper end wall 5 of the drive shaft hole 4. As shown in FIG.

[Problem that the invention seeks to solve] However, according to the former gate arrangement described above.

Welding bottle 7 is crushed by welding, so forming 1! /Although it has the advantage of not having to perform a gate removal process, since the welding bin 7, which is the gate part, is located off-center from the center of the reel body 2, the material may flow toward the cavity and cause molding defects. Easy to invite.

On the other hand, according to the latter gate arrangement, since the gate section is located inside the drive shaft hole 4, not only is there no need to perform special removal treatment for data marks, but also the gate section is located inside the drive shaft hole 4. Since it is located at the center in the i\ direction, there is an advantage that the material flows uniformly throughout the cavity without being biased toward the cavity. However, when the gate part is placed in the drive shaft hole 4 which has a double blind alley shape.

This makes it difficult to lower the temperature of the core block in which the drive shaft hole 4 is molded, resulting in a disadvantage that the molding cycle increases significantly.

Furthermore, since it is difficult to uniformly cool the core block, there is a disadvantage that internal distortion tends to remain in the reel body 2 due to the difference in shrinkage of the materials.

This invention was made to solve the above-mentioned conventional problems, and aims to improve molding accuracy, reduce internal distortion, and further improve productivity by devising the gate arrangement. 1 purpose.

A second object of the present invention is to improve the workability of gate processing and ensure a good spring receiving function by devising a gate processing method.

[Means for solving problems]

This invention takes the following measures to achieve the above object. That is, in order to achieve the first object, in the present invention, the spring receiving post 6 portion provided at the center of the outer surface of the reel body 2 in the axial direction m is positioned at the game 1-G.

In order to achieve the second object, in the present invention, after the reel body 2 is molded, the spring receiving boss 6 is thermally melted to smooth and eliminate the gate mark a.

Here, as a means of melting and smoothing the gate trace a of the spring receiver boss 6 by heat melting, a predetermined shape on the top of the tip of the spring receiver boss 6 is created so that heat is generated in a very short time so that the melting and shaping work can be carried out efficiently. It is preferred to use an ultrasonic horn 18 with conforming four parts 19, but there are also nine other parts, e.g.
It may also be a heating plate or the like that uses electric heat as a heat source.

In addition, when a welding pin 7 is provided protrudingly on the end surface of the reel body 2 having the spring receiving boss 6 and is crimped and welded to the upper flange 3, the crimping and welding operation of the welding pin 7 is performed on the spring receiving boss 6. It is more preferable to use the same ultrasonic horn 18 or hot plate for both processes so that the process can be carried out simultaneously with the process for eliminating gate marks.

Furthermore, there is a recess 19 of the ultrasonic horn 18 in which the gate mark of the spring receiving boss 6 is removed.

It can be said that it is preferable to provide a small protrusion 21 so that only the gate m at the tip of the spring receiving boss 6 can be locally strongly pressed, in order to more reliably eliminate gate marks.

[Effect]

In this case, during injection molding of the reel body 2, the molten resin is injected from the radial center position of the entire reel body 2, so that the resin is uniformly flowed throughout the cavity without drifting. Further, since the gate G is disposed outside the drive shaft hole 4 of the reel body 2, it is possible to pass the cooling circuit 17 through the core block 16 for forming the drive shaft hole.

The cooling power 'R1) is carried out efficiently and uniformly, making it possible to speed up the molding cycle and reduce internal strain.

Scratch marks from the gate cut portion that are formed on the spring receiving boss 6 after molding can be easily and reliably eliminated by melting the spring receiving boss 6 and shaping it, and the reel presser plate spring 12 can be stably removed. I will accept and support it.

〔Example〕

Two embodiments of the present invention will be described below with reference to FIGS. 1 to 3. The structure of the target plastic tape reel itself is almost the same as the conventional one described above, so the same reference numerals are given and the explanation thereof will be omitted.
Only the differences from conventional manufacturing methods will be explained.

Figure 1 shows the structure of the molding die for the reel body 2 with a lower flange, where 13 is a fixed die, ]4 is a movable die, and +5 is a fixed die.
is a cavity, and G is a gate, which are set at a position corresponding to the tip top of the spring receiver 1.3 housing 6 at the center of the upper surface of the second end wall 5 of the reel body 2, which is the molded product, on the fixed mold 13 side. . Then, on the movable mold 14 side, the reel body 2
A cooling circuit 1 is installed in the core block 16 for forming the drive shaft.
7 is included.

In this manner, molten resin is injected into the cavity 15 through the gate G to form the lower flange round body 2 having the spring receiver LJ boss 6 and the welding bottle 7.

At this time, since the game 1-G is located at the radial center position of the reel body 2, the molten resin is uniformly flowed into the cavity 15. Then, when the molded product is taken out, it is cooled and solidified.
At this time, the inner surface of the cul-de-sac shaped glue body 2 is uniformly cooled and solidified in a short time by the cooling circuit 17 in the core block 16.

Next, the scratch mark a of the gate cut portion remaining at the tip of the spring receiver boss 6 is removed and shaped by the ultrasonic horn 18 shown in FIG.

-1- The flange 3 is caulked and the welding pin 7 is welded to the reel body 2, thereby performing the work of integrally joining the two together. That is, a recess 19 that matches the shape of the top of the tip of the spring receiving boss 6 is provided at the tip of the ultrasonic horn 18;
The ultrasonic pawn 18 mechanically vibrates the spring receiving boss 6 and the welding bottle 7 to generate heat, thereby crushing the welding pin 7. The gate mark a is crushed and made smooth, and the locking pin 7 is caulked and welded. In addition.

If a small protrusion 21 is provided in the recess 19 of the ultrasonic horn 18 to prevent the gate trace a from being pushed locally,
As shown in FIG. 3, the gate trace portion at the tip of the spring receiver boss 6 is shaped into a depressed shape to more completely eliminate the gate trace.

〔Effect of the invention〕

As explained above, according to the present invention, the reel body 2
2 quality because the reel body 2 is injection molded with the reel body 2 positioned at a location corresponding to the tip of the spring receiving boss 6 that is protruded and retracted into the radial center of the reel body 2.

Accuracy can be improved and productivity can be significantly improved. Moreover, the gate vI at the top of the tip of the spring receiver boss 6
Fa can be easily and reliably eliminated by smooth melting and shaping with heat melting, and has the advantage that it can stably contact the reel presser plate spring 12 and ensure a good receiving function.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing the configuration of a molding die used directly in carrying out the present invention, Fig. 2 is a cross-sectional view showing a part of the ultrasonic horn and tape reel used for gate processing, and Fig. 3 is a cross-sectional view showing a part of the ultrasonic horn and tape reel used for gate processing. It is a sectional view showing a spring receiving boss after processing. FIG. 4 is a sectional view of a tape cartridge incorporating a conventional tape reel, and FIG. 5 is a sectional view of a reel body with a lower flange of the tape reel. 1...Tape reel. 2...Reel body. 3...Top flange. 4... Drive shaft hole. 5...Top end wall. 6...Spring receiver boss. 7...Welding bottle. 8...Lower flange, 18...Ultrasonic horn. 19...Four parts. a...Day 1-trace. G...Gate. Inventor Tatsuo Araki = 91 et al.

Claims (2)

[Claims] (1) When manufacturing a plastic tape reel in which the spring bearing boss 6 is integrally protruded from the center of the outer surface of one axial end of the reel body 2, resin is injected into the tip of the spring bearing boss 6. A method for manufacturing a tape reel, comprising the steps of positioning a gate G for injection molding, and after the molding, thermally melting the spring bearing boss 6 to smooth and eliminate the gate mark a. (2) An ultrasonic horn 18 having a concave portion 19 that matches the shape of the tip of the spring receiving boss 6 is used as a means for eliminating and shaping the gate trace a of the spring receiving boss 6 by thermal melting. ) The method for manufacturing the tape reel described in item 2.