JPH0316875B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention relates to a method for manufacturing doll members made of synthetic resin.

(Prior art and its problems) In general, dolls for the purpose of emotional and intellectual education during the growth process of boys and girls are composed of several parts such as heads, arms, legs, and torsos, and usually these parts are the main parts. They are made from vinyl chloride resin and are manufactured using different manufacturing methods depending on the purpose. For example, the head is manufactured using rotation molding, the body using injection molding, and the arms and legs using slush molding.

However, in any case, the molded member is difficult to bend due to the hardness and softness of the material, or even if it is bent, it quickly returns to its original shape when the synthetic resin is used alone. As a result, the bending of joints such as elbows and knees becomes unnatural and lacks realism.Dolls are expected to have the same basic movement function as humans, in which each part of the body can bend and stretch, as well as maintain its bent state. ing.

As a solution to this problem, it has been proposed to embed a core metal inside the doll member and use the core metal to suppress the restoring force of the resin part and maintain the bent state of the molded object. executed by. After injecting the molten resin sol into the mold, the air bubbles in the sol are discharged, and after baking, the uncured vinyl chloride resin sol in the mold is discharged, and then the steel core is inserted into the mold. The core metal is embedded in the molded body by inserting it and then firing it,
A doll member in which a core material is embedded is manufactured through a cooling and removal process. However, this molding method had the following drawbacks.

(1) In the slush molding method, the molded body is hollow, so the core metal position tends to shift and the core metal cannot be held at the center of the molded body. For this reason, it is impossible to avoid the tendency for the bending and stretching to be deviated from the center.

(2) When a hollow molded body is bent, the bent portion deforms unnaturally.

(3) In the above molding method, the molded bodies are removed from the mold by being pinched with a tool and forcibly pulled out, so the dimensions are all different. For this reason, members that form pairs, such as arms and legs, must be sorted into similar groups, which is a cumbersome task.

(4) Productivity is low because there are many molding steps and the molding time takes about 270 seconds.

For this reason, it has been considered to produce a molded body containing a cored metal by injection molding, but carrying out this molding method involves the following technical difficulties.

(1) It is technically difficult to hold the core in the center of the mold. In other words, in the injection molding method, considerable resin flow pressure is generated when molten resin is injected into the mold, but in order to firmly hold the core in the same position against this resin flow pressure, the mold The problem is how and by what means to fix the core metal inside. If an attempt was made to hold this with a pin or the like, it would be technically possible, but the pin hole would remain in the doll member after molding, which would impair its commercial value.

(2) Even if the core metal can be retained, post-processing is required to remove it so that it does not protrude from the doll member, but in order to ensure safe removal,
It is not sufficient to simply remove the protruding portion from the molded doll member. This is because during use, the buried portion may break naturally or internally and protrude. Since product safety is an important issue related to the life of a company, it is an extremely difficult problem to configure a means to carry out this process efficiently and reliably.

(3) Since vinyl chloride resin has a high thermal shrinkage rate, dimensional shrinkage (5 to 20%) occurs after molding, resulting in variations in the dimensions of molded parts. Moreover, since the metal core metal has a small shrinkage rate, there is a possibility that the metal core protrudes from the molded member after molding. How to solve this problem is also an important issue.

Due to the many technical difficulties described above, molding of cored members by injection molding was conventionally abandoned.

(Objective of the invention) This invention solves the above problems, and uses a core material made of a composite material of metal and synthetic resin, and uses an injection molding method to achieve safety, uniform dimensions, and high productivity. The object is to provide a manufacturing method for manufacturing doll leg members made of synthetic resin.

(Structure of the Invention) In order to achieve the above-mentioned object, the method for manufacturing a synthetic resin doll member according to the present invention provides a core metal having a bent portion at one end and a meandering portion at the middle portion, and a tip end facing outward at the other end of the core metal. In the next step, a core material made by connecting synthetic resin aggregates with integrally protruding space-retaining protrusions is held in the molding space of a mold for injection molding of doll leg parts, and molded. Characterized by processing.

(a) inserting and holding the tip of the bent portion of the core metal into an insertion hole formed in the inner wall of the molding space of the mold, and sandwiching the free end of the aggregate between the joints of the mold; Furthermore, the core metal is arranged from the upper end of the leg formed in the molding space to the lower part of the knee, the meandering part is arranged at a part corresponding to the thigh part of the leg, and the straight part below the meandering part is arranged. The process of placing the on the knee.

(b) A step of injecting and molding molten vinyl chloride resin into the molding space.

(c) After taking out the molded leg member from the mold, a step of treating the end portion of the aggregate protruding from the leg member.

(Operations and Effects of the Invention) As described above, according to the present invention, first, the core material has a composite structure of a metal core bar and a synthetic resin aggregate;
To set this in a mold, it is only necessary to insert one end into the insertion hole of one of the molds and hold it there, and to hold the other end between the joints of the mold, so the work is very easy. Further, the aggregate is formed with a spacing protrusion, so that the inner wall of the mold and the aggregate are always kept at the same distance, so that the core material is firmly held at the central position within the mold. In addition, since a meandering part is provided in the middle of the core metal, when molten vinyl chloride resin is injected into the mold, the intermediate meandering part of the core metal absorbs and softens the resin flow pressure. The material is held in a central position within the mold against the resin flow pressure. Therefore, it is possible to mold a doll member that can be bent naturally without being deviated from the center.

Furthermore, since the meandering portion is placed on the thigh portion, which has a large cross-sectional area, and the straight portion is placed on the knee portion, which has a small cross-sectional area, high processing accuracy of the core metal is not required.

In addition, since the aggregate is integrally provided with a spacing protrusion with a pointed tip protruding outward, the contact of the spacing protrusion with the inner wall of the mold is a point contact.
The molten resin also wraps around between the holding protrusion and the inner wall of the mold.

Next, the insertion end of the core metal protrudes from one end of the doll member taken out from the mold, and the clamping end of the aggregate protrudes from the other end, but since the aggregate is made of synthetic resin, In addition to being less dangerous than metal,
By providing a thin break-off part inside the doll member, complete removal can be carried out technically and easily. Removal of the aggregate ensures that the aggregate end of the doll member is safe. On the other hand, the ends of the core protrude outward, but the doll is constructed by connecting the head, arms, and one end of the legs to the body, and the connecting parts of each member are housed within the doll's body. , does not appear externally.
Therefore, by providing the insertion end of the core metal in the part of each member that corresponds to the connection part with other members, the end on the core metal side will fit inside the doll's body when connected, so it will not be exposed to the outside. However, safety can be fully guaranteed even if it is not completely processed. As a result, the safety of the final product is 100% satisfied.

Furthermore, regarding the shrinkage of the molded part after molding,
Since the core material is a composite structure material of a core metal and aggregate, it has many uneven parts, and these uneven parts become an obstacle to shrinkage, thereby suppressing the shrinkage of the vinyl chloride resin part. Similarly, since a meandering portion is formed on the core metal, this portion hinders resin shrinkage for the same reason. Furthermore, since the synthetic resin aggregate occupies a high proportion of the molded member, the proportion of the resin portion is relatively low, and the degree of shrinkage thereof can also be suppressed to a low level. These act synergistically to suppress shrinkage of the vinyl chloride resin portion, making it possible to obtain a molded member with high dimensional accuracy.

Furthermore, injection molding is safer in operation and requires fewer steps than slush molding, so overall productivity can be significantly improved.

(Example) Hereinafter, an example of manufacturing a leg member of a doll will be described with reference to the drawings.

First, the gist of this invention is to construct a core material in a composite manner from a metal core bar and a synthetic resin aggregate.Next, when molding doll parts, this composite core material is placed in the center of a mold. After positioning and fixing, molten synthetic resin is injected into the mold and injection molded, and finally the tip of the core material is post-treated.

Therefore, first, the structure of the core material will be explained, and then the molding method will be explained for the leg members of the doll.

In the figure, numeral 1 indicates a core material. This core material 1
As shown in Figures 1 and 2, the metal core 2
It is a composite material consisting of a synthetic resin aggregate 3 and a synthetic resin aggregate 3. In this example, the core metal 2 is preferably one with small spring back, high mechanical strength, and good thermal conductivity.In this example, a metal core made of a special aluminum alloy is used, one end 4 of which is bent, and approximately the middle A meandering part 5 is formed at one end, and a hook-shaped bent part 6 is formed at the other end.
is formed.

The aggregate 3 is preferably one that has a higher heat deformation temperature than vinyl chloride resin and has excellent mechanical strength.
In this example, one made of polyacetal resin was injection molded. The aggregate 3 is composed of a core holding portion 7 and a core portion 8. A core metal holding groove 9 is formed in the core metal holding portion 7 and is open on the top surface and one side surface. On the opposing inner walls of the side opening 9a of the holding groove 9, protrusions 10, 10 are provided facing each other so that the distance between them is slightly smaller than the diameter of the core bar 2. Further, the same inner walls are connected at the lower part by a connecting piece 12, and a receiving hole 13 for receiving the bent part 6 of the core bar 2 is formed at the lower end of the holding groove 9 by the connecting piece 12. . The size of this receiving hole 13 is slightly larger than the diameter of the core metal 2. Then, the receiving hole 1 in the holding groove 9
The opposite side to 3 is open. The core part 8 is formed into a plate shape, and reinforcing ribs 14 are provided on both sides of the upper part.
14 is formed, and a thin break-off portion 15 is formed at the bottom. Furthermore, a pair of protruding spacing protrusions 16, 16 are formed protruding outward from both opposing sides of the core metal holding part 7 and the core part 8. These holding protrusions do not necessarily need to be provided in pairs, nor do they need to face in the same direction.

When forming the core 1 from the core 2 and the aggregate 3, as shown in FIG. Part 9a
Insert the facing protrusion 10 diagonally from the
When the core bar 2 is pushed into the holding groove 9 from between the two opposing protrusions 10, the core bar 2 rotates around the part that abuts the connecting piece 12, and the distance between the facing protrusions 10, 10 is determined by the elasticity of the aggregate 3. Since the core bar 2 is held in the retaining groove 9, the core bar 2 is held in the retaining groove 9, and at the same time, the bent part 6 at the lower end
is inserted into the receiving hole 13 of the aggregate 3. As a result, the metal core 2 in the holding groove 9 does not come off from the upper opening, and since the metal core 2 in the holding groove 9 receives resistance from the facing protrusions 10, 10 at the side opening, it cannot easily come off. Therefore, the core metal 2 is well held within the holding groove 9 of the aggregate 3. Note that since the size of the receiving hole 13 is slightly larger than the diameter of the core metal 2, a clearance is created between the bent portion 6 of the core metal 2 and the receiving hole 13.

Next, a method of molding the leg members of a doll by injection molding using the core material having the above structure will be described.

First, as shown in Fig. 3, the injection mold 2
0 and 21 are formed with a molding space S for the doll's leg members, an insertion hole 22 is formed in one of the molds 20 at the upper end, and both molds 2 are formed at the lower end.
A clamping portion 23 is formed at the seam of 0 and 21.

Therefore, the core material 1 having the above structure is set in the molding space S of the molds 20 and 21. In this case, mold 2
0 and 21, one end of the core bar 2 has a bent part 4.
is inserted into the insertion hole 22 formed in the inner wall 20a of the mold 20 and held therein, while the core 8 of the aggregate 3
The tip 8a of the mold 20, 21 is held by
be held in between. Further, the core metal 2 is arranged from the upper end of the leg formed in the molding space to the lower part of the knee, the meandering part 5 is arranged at a part corresponding to the thigh of the leg, and the meandering part 5 is By arranging the lower straight part 5a at the knee part, the core material 1 is placed in the molding space S.
It is held and fixed in the center position. The time required to set the core material 1 is about 5 seconds, and the work is very easy.

Next, the mold 2 is molded according to the usual injection molding method.
Inject molten vinyl chloride resin at 170° to 180°C within 0.21°C. At this time, considerable resin flow pressure is applied to the core material 1 within the molding space S. However, since the core material 1 is held by the molds 20 and 21 at its upper and lower ends, and the bent portion 4 at the end on the resin inflow side is held at right angles to the resin flow, it cannot sufficiently resist the flow pressure. obtain. Furthermore, since the meandering portion 5 is formed on the core bar 2, this meandering portion 5 acts as a resistance to the resin flow pressure and relieves it, so that the resin flow pressure on other parts is alleviated. In addition, against the resin flow pressure acting on the aggregate 3, the tips of the spacing protrusions 16, 16 are always in contact with the mold inner walls 20a, 21a, and the aggregate 3 is constantly
and the mold inner walls 20a, 21a. Therefore, the position of the core material 1 hardly shifts due to the resin flow pressure.

Mold inner walls 20a, 2 of spacing protrusions 16, 16
Since the contact with 1a is point contact, the molten resin contacts the holding protrusions 16, 16 and the mold inner walls 20a, 21a.
It also goes around between. Further, since the aggregate 3 has a high molding temperature, it does not deform at all when the molten resin is injected. Furthermore, since the core metal 2 of the core material 1 is made of a special aluminum alloy with good thermal conductivity, no temperature difference occurs between it and the surrounding molten resin. Similarly, since the aggregate 3 has a high heat deformation temperature, it will not be deformed at all by the injection of molten resin.

The time required for the above injection molding process is 50 to 60 seconds.

Next, after the molding is completed, the molds 20 and 21 are removed and the doll member is taken out. As a result, it is possible to obtain a doll leg member 25 in which the core material 1 is embedded.
At this time, the end of the core metal 2 protrudes from the bent portion 4 at one end of the leg member 25, and the tip 8a of the aggregate 3 protrudes from the end on the leg tip side. Tip 4 of core bar 2
When connecting to the body part (not shown) when assembling the doll,
Since it fits within the body and is not exposed to the outside, it is safe even without cutting. Aggregate tip 8a
When the leg member 25 is gate cut, the break-off portion 1
Just break it off from 5. Since the break-off portion 15 is provided inside the leg member 25, the tip of the broken-off remaining portion remains inside the doll member 25 and does not protrude to the outside, so it is safe. This process of taking out the molded member and treating the aggregate can be carried out in as little as 10 seconds.

By the way, after the molding is completed, the vinyl chloride resin in the leg members 25 contracts. However, in the part of the leg member 25 where the aggregate 3 is buried, the ratio of the aggregate 3 to the resin part is large, so the resin content is relatively small, and the degree of shrinkage is also small. In addition, a wall perpendicular to the longitudinal direction of the leg member 25 is formed between the core bar holding part 7 and the core part 8, and this wall prevents the resin from shrinking. Resin shrinkage is minimized. In addition, in the part of the leg member 25 in which the core metal 2 is buried, a meandering part 5 that meanders in the longitudinal direction of the leg member 25 is formed approximately in the middle of the core metal 2. Suppresses resin shrinkage in the direction. Therefore, the dimensional accuracy of the leg member 25 is extremely high. In addition, since a clearance is formed between the tip bent portion 6 of the core metal 2 and the receiving hole 13 of the aggregate 3, distortion due to differences in thermal conductivity and thermal contraction rate due to molding heat during molding can be avoided. It is absorbed and there is no risk of cracking or the like occurring in the leg member 25.

The leg member 25 obtained in this way has a core metal 2
is buried, so by bending this, the core bar 2 of the core member 1 will also bend, but the core bar 2 will not fit into the leg member 2.
5, the bending and returning directions will not be unnaturally biased. Since the core metal 2 is made of a special aluminum alloy with small springback,
When the leg member 25 is bent, the bent state of the leg member 25 can be maintained by suppressing the elastic restoring force of the vinyl chloride resin portion. Although the aggregate 3 of the core material 1 does not bend, it does not cause any inconvenience because it is placed in the part of the leg member 25 that does not require bending. Therefore, a doll member having bending performance that approximates human movement can be obtained.

In addition, the core material 1 uses a special aluminum alloy as the core metal 2, and the bending part at the tip of the core metal 2 is hooked into the receiving hole 13 of the aggregate 3, so the repeated bending and undoing ability is extremely high. . As a result of a 90 degree bending test at one second intervals, the conventional steel core became unusable after 10 to 15 cycles, but the core bar 2 of this example was confirmed to have 10 to 12 times the bending performance.

To summarize the effects of the above-mentioned molding methods,
It is as follows.

(1) Simplify the molding process and improve productivity.

Since molding can be performed using injection molding, the number of steps is approximately 3 compared to the conventional slush molding method.
The molding time could be reduced to 1/3 to 1/4. Furthermore, the core material can be easily and reliably set into the mold during molding, and the injection molding method is safer to work with than the slush molding method. Therefore, overall productivity was significantly improved.

(2) Ensuring the safety of molded parts.

Since the core material is constructed as a composite core material in which a metal core metal and a resin aggregate are connected, the core metal and the aggregate protrude from the doll member. However, if the core metal is placed in the connecting part with other doll parts in the molded part, and the aggregate is placed on the other side, the core metal will be housed inside the doll's body and will not be exposed to the outside. Since the projecting ends of the aggregate can be broken off from inside the molded part, the molded part is completely safe.

(3) Improving the performance and dimensional accuracy of molded parts.

Since the central position of the core material within the molded member is maintained during injection molding, the bending direction of the molded member is not biased and a natural bending state can be maintained, resulting in the molded member having excellent bending performance. In addition, shrinkage after molding can be effectively suppressed, resulting in excellent dimensional accuracy.
In addition, the repeated bending ability is good, and it is possible to prevent cracks in the molded member due to differences in thermal shrinkage rates.

(4) Relaxation of machining accuracy Since the meandering part of the core metal is placed in the thigh area, which has a large cross-sectional area, and the straight part is placed in the knee area, which has a small cross-sectional area, high machining accuracy of the core metal is not required.

Although the above-mentioned embodiment relates to the leg members of the doll, the arms and body members can also be molded in the same manner as described above.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the core material used in this invention;
The figure is a vertical cross-sectional view of the core material, FIG. 3 is a vertical cross-sectional view of the mold showing the state in which the core material is set in the mold, and FIG.
Figures a and b are partial cross-sectional views of the leg members of the molded doll. Symbol S...molding space, 1... core material, 2... core metal, 3... aggregate, 4... bending part, 5... meandering part,
6...Bending part, 7... Core bar holding part, 8... Core part, 9... Holding groove, 13... Receiving hole, 15... Breaking part, 16... Spacing holding protrusion, 20, 21...
Mold, 22... insertion hole, 23... clamping part.

Claims (1)

[Scope of Claims] 1. Synthetic resin aggregate having one end bent and a core metal with a meandering part formed in the middle part, and a spacer retaining protrusion with a pointed tip protruding outward from the other end. A synthetic resin doll member, characterized in that the core material is connected to the core material to form a core material, and the core material is held in a molding space of an injection mold for a doll leg member and molded in the following process. manufacturing method. (a) inserting and holding the tip of the bent portion of the core metal into an insertion hole formed in the inner wall of the molding space of the mold, and sandwiching the free end of the aggregate between the joints of the mold; Furthermore, the core metal is arranged from the upper end of the leg formed in the molding space to the lower part of the knee, the meandering part is arranged at a part corresponding to the thigh part of the leg, and the straight part below the meandering part is arranged. The process of placing the on the knee. (b) A step of injecting and molding molten vinyl chloride resin into the molding space. (c) After taking out the molded leg member from the mold, a step of treating the end portion of the aggregate protruding from the leg member.