JPH11314246A - Molded product having movable part and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molded product having a movable part capable of being reduced in production cost by performing the in-mold assembling of the movable part by a general-purpose injection molding machine and a method for producing the same. SOLUTION: The first cavity 10 corresponding to the shape of a part main body and the second cavity 11 corresponding to the shape of a lid 3 are provided to a mold 9. A slide core 13 is provided in a movable mold 9b at the position corresponding to the leading end part of the lid 3 in the second cavity 11 so as to be capable of being projected and retracted. A resin is poured into the second cavity 11 from a primary molding gate 14b to injection mold the lid 3 having a hole. Next, the mold is opened and the movable mold 9b is rotated centering around an axis X by 180 deg. and the slide core 13 is retracted from the hole. After mold clamping, the same resin is poured into the first cavity 10 to injection mold the part main body and the shaft part of the part main body is formed in the state inserted into the hole of the lid 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded article having a movable part and a method for manufacturing the same.

[0002]

2. Description of the Related Art In conventional injection molding, there is known a so-called two-color molding in which a movable portion is assembled in a mold so that assembly after molding can be omitted. Two-color molding is performed by using a two-color molding machine having two cylinders, injecting different synthetic resins melted from each cylinder, and as a result, a molded article made of two types of synthetic resins is produced. . In the two-color molding, two types of synthetic resins that do not adhere to each other (for example, a combination of an ABS resin and a POM resin) are used. Therefore, in a molded product manufactured by two-color molding, two types of synthetic resins do not adhere to each other, so that two components are connected to each other via a movable part so as to be relatively movable (assembled state). As a result, assembly after molding can be eliminated.

[0003]

However, two-color molding required a two-color molding machine having two cylinders as described above. Therefore, the two-color molding machine is more expensive than a general-purpose injection molding machine, and as a result, the production cost of molded articles has risen.

An object of the present invention is to provide a molded article having a movable part which can reduce the manufacturing cost by assembling the movable part in a mold using a general-purpose injection molding machine, and a method of manufacturing the same.

[0005]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, a primary molded product and a secondary molded product have a movable portion which is relatively movably connected via a connecting portion. In the method of manufacturing a molded article, when molding the primary molded article, a core member is disposed at a position corresponding to the connecting portion in a cavity for a primary molded article formed in a mold, and a first member is formed.
Injection molding a primary molded product having a hole in the support portion, when molding the secondary molded product, after retracting the core member from the hole of the primary molded product, to the same material as the primary molded product Injection molding of the secondary molded product
The gist of the present invention is a method for manufacturing a molded article having a movable portion, wherein the projection of the support section is formed so as to be fitted into the hole of the first support section of the primary molded article.

According to a second aspect of the present invention, there is provided a method of manufacturing a molded product having a movable portion in which a primary molded product and a secondary molded product are relatively movably connected via a connecting portion. After molding the primary molded product having the holes formed therein, the first support portion of the primary molded product is set in a state of being disposed in a cavity for a secondary molded product formed in a mold, and the primary molding is performed. Injection molding of the secondary molded article with the same material as the article, and forming the projection of the second support portion of the secondary molded article in a state of being inserted into the hole of the first support section of the primary molded article. The gist of the present invention is a method of manufacturing a molded article having a movable portion characterized by the following.

[0007] The third aspect of the present invention is the first or second aspect.
In the method for manufacturing a molded article having a movable portion according to the above, when molding the primary molded article, injection molding of a molten crystalline resin, when molding the secondary molded article, the molding of the primary molded article When the injection timing is different from the injection molding,
The gist of the invention is to perform injection molding of the same crystalline resin as the primary molded article.

According to a fourth aspect of the present invention, there is provided a method for manufacturing a molded article having a movable portion according to any one of the first to third aspects, wherein the primary molded article and the secondary molded article are connected via a connecting portion. A molded part having a movable part connected to be relatively movable, and a hole is formed in the primary molded part side of the coupling part, and is formed of the same material as the primary molded part of the coupling part. A protruding portion is formed on the side of the secondary molded product, and the protruding portion is fitted into the hole, and the gist is a molded product having a movable portion.

According to the first aspect of the present invention, when a primary molded product is molded, injection molding is performed in a state where the core member is arranged at a position corresponding to the connecting portion of the primary molded product.
A primary molded article having a hole in the support is formed. Next, when the secondary molded article is molded, the secondary molded article is injection-molded with the same material as the primary molded article with the core member retracted from the hole of the primary molded article. Then, a secondary molded product including the second support portion having the projection fitted into the hole of the first support portion of the primary molded product is formed. That is, when molding a primary molded product and a secondary molded product, injection molding is performed using the same material. Therefore, it is not necessary to use a two-color molding machine, and a molding having a movable portion in which a primary molded product and a secondary molded product are relatively movably connected via a connecting portion by a single cylinder injection molding machine. An article is formed.

According to the second aspect of the present invention, a primary molded article having a hole formed in the first support portion is formed. Next, in a state where the first support portion of the primary molded product is disposed in the cavity for the secondary molded product formed in the mold, injection molding of the secondary molded product is performed using the same material as the primary molded product. Will be Then, a secondary molded product including the second support portion having the projection fitted into the hole of the first support portion of the primary molded product is formed. That is, when molding a primary molded product and a secondary molded product, injection molding is performed using the same material. Therefore, it is not necessary to use a two-color molding machine, and a molding having a movable portion in which a primary molded product and a secondary molded product are relatively movably connected via a connecting portion by a single cylinder injection molding machine. An article is formed.

According to the third aspect of the present invention, the molten crystalline resin, in this case, among the crystalline resins, in particular, when the injection timing is different, the crystalline resins which do not adhere to each other even if they are melted at the same temperature are formed by injection molding. A primary molded article is formed. Next, when the injection timing is different from that at the time of injection molding of the primary molded product, a secondary molded product is molded by injection molding the same molten crystalline resin as the primary molded product. Here, if the injection timings are different, injection molding is performed using a crystalline resin that does not adhere to each other even if it is melted at the same temperature, so that the primary molded product and the secondary molded product do not adhere to each other. Accordingly, a molded article having a movable portion in which the primary molded article and the secondary molded article are relatively movably connected via the connecting section is formed.

According to the fourth aspect of the present invention, the protrusion of the secondary molded product is inserted into the hole of the primary molded product. In other words, the molded article having a movable part is not necessary to assemble after molding because the primary molded article and the secondary molded article are connected so as to be relatively movable via the connecting portion, and the molded article is sent to the next step as it is. Can be. Therefore, the manufacturing process can be simplified.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a hinge-shaped part 1 as a molded article having a movable part has a component body 2 as a secondary molded article and a lid 3 as a primary molded article via a hinge 4 as a connecting part. And are connected so as to be relatively rotatable. The hinge part 4 includes a second support part 5 formed on the component body 2 and a first support part 6 formed on the lid 3.

The component body 2 is formed in a substantially cylindrical shape, and a second support portion 5 is provided on one end surface thereof. The second support portion 5 is formed so as to protrude from one end surface of the component body 2,
The tip 5a of the second support 5 is formed in a columnar shape.
The shaft 5 as a projection is provided on both end surfaces of the tip 5a.
b is projected. The component body 2 is provided with the first engagement portion 7 at a position 180 degrees opposite to the position at which the second support portion 5 is provided around the center axis α of the component body 2.

The lid 3 is provided with a first support portion 6 on its outer peripheral surface. The first support portion 6 is formed so as to project in a direction substantially perpendicular to the outer peripheral surface of the lid 3. Two tip portions 6a of the first support portion 6 are provided so as to sandwich the tip portion 5a of the second support portion 5 when the component body 2 and the lid 3 are connected. The tip 6a is formed in a cylindrical shape having a hole 6b. The lid 3 is provided with a second engaging portion 8 at a position 180 degrees opposite to the position where the first support portion 6 is provided around the center axis β of the lid 3.

The component body 2 is inserted into the two holes 6b of the lid 3.
Of the hinge-shaped part 1 and the lid 3 are connected so as to be relatively rotatable. The second engaging portion 8 is fitted to the first engaging portion 7 by rotating the lid 3 toward the component main body 2, and the hinge-shaped component 1 is in a closed state.

If the injection timings of the component body 2 and the lid 3 are different, a crystalline resin that does not adhere to each other even if they are melted at the same temperature is used. In this embodiment, a polyacetal resin is used for both.

Next, a method of manufacturing the hinge-shaped component 1 configured as described above will be described. The hinge part 1 is shown in FIG.
As shown in the figure, the mold is manufactured using a mold 9 composed of a fixed mold 9a and a movable mold 9b and an injection molding machine (not shown). The movable mold 9b is configured to be rotatable about the axis X. The mold 9 has a first cavity 10 as a cavity for a secondary molded product corresponding to the shape of the component body 2 and a cavity for a primary molded product as a space corresponding to the shape of the lid 3. The second cavity 11 is provided. In the mold 9, 1 around the axis X.
A first cavity 10 which is a space corresponding to the shape of the component body 2 and a second cavity 11 which is a space corresponding to the shape of the lid 3 are provided at positions symmetrical by 80 degrees. Further, a slide core 13 as a core member is provided in the movable mold 9 b so as to be able to protrude and retract at a position corresponding to the hinge part 4 of the primary molded product in the second cavity 11. The slide core 13 is formed in a column shape.

The injection molding machine is provided with a single cylinder (not shown), and the resin (polyacetal resin in this embodiment) melted from the cylinder is sprue 1
2. Injected through runners 14a, 15a and gates 14b, 15b.

The hinge-shaped part 1 is manufactured by molding a lid 3 as a primary molded article and then molding a component body 2 as a secondary molded article. In the following method of manufacturing the hinge-shaped part 1, for convenience of explanation, the right side of FIG.
4), the right side of FIG. 4, the left side of FIG. 5, the left side of FIG.
Although the description will be made in the order of the left side of FIG. 3 and the left side of FIG. 4, the work is actually performed simultaneously on the opposite side in FIGS.

First, as shown on the right side (primary molding side) of FIG. 3, a resin is poured from the primary molding gate 14b into the second cavity 11, and the lid 3 is injection molded. At this time, as shown in FIG.
3 is disposed, and the distal end portion 6a of the first support portion 6 of the lid 3
Is formed with a hole 6b.

Next, the movable mold 9b is opened and brought into a state shown on the right side of FIG. At this time, the lid 3 is moved downward with the movable mold 9b. Then, as shown in FIG.
After rotating the movable mold 9b by 180 degrees about the axis X, the movable mold 9b is clamped to join the fixed mold 9a and the movable mold 9b to obtain the state shown in FIG.

Then, as shown in FIG. 8, the slide core 13 in the second cavity 11 is moved to both sides of the first support portion 6, and the slide core 13 is retracted from the hole 6b. In this state, when the resin is poured from the secondary molding gate 15b into the first cavity 10, the state shown in the left side (secondary molding side) of FIG. 3 is reached, and the component body 2 is injection molded.
At this time, as shown in FIG. 8, the resin is introduced into the hole 6b, and the distal end portion 5a of the second support portion 5 of the component body 2 has the hole 6b.
Is formed.

Here, if the injection timing is different for the materials of the lid 3 and the component body 2, a crystalline resin that does not adhere to each other even if they are melted at the same temperature (in this embodiment, both polyacetal resins) is used. Therefore, the lid 3 and the component body 2
Are not fixed to each other, and the lid 3 and the component main body 2 are formed so as to be relatively rotatably connected via the hinge 4.

Next, when the movable mold 9b is opened, FIG.
As shown on the left side of the figure, the hinge-shaped part 1 after molding is protruded from the movable mold 9b by an extrusion pin (not shown) inserted into the movable mold 9b. Therefore, the second support 5 and the first
The hinge-shaped part 1 connected to the supporting part 6 so as to be relatively rotatable can be manufactured.

When the lid 3 is injection-molded on the right side (primary molding side) in FIG. 3, at the same time, on the left side (secondary molding side) in FIG. The component body 2 is injection-molded with respect to 3. That is, the mold 9
In the inside, what is called setting is performed in which different shapes are formed in the same mold. Then, as shown on the left side of FIG.
When the movable mold 9b is opened, the hinge-shaped part 1 described above is opened.
The hinge-like part 1 which is one before is taken out. FIG.
When the component body 2 is injection-molded on the left side (secondary molding side), the lid 3 that is one step behind the lid 3 is injection-molded on the right side (primary molding side) in FIG.

Therefore, according to the present embodiment, the following effects can be obtained. (1) In the present embodiment, when the lid 3 is formed,
Injection molding is performed with the slide core 13 disposed at a position corresponding to the distal end 6a of the first support portion 6 of the first support portion 6.
A lid 3 having a hole 6b in a was formed. Next, the component body 2
When the slide core 13 was retracted from the hole 6b of the lid 3, the component body 2 was injection-molded using the same material (polyacetal resin) as the lid 3. And
The component main body 2 including the second support portion 5 having the shaft portion 5b fitted in the hole 6b of the first support portion 6 of the lid 3 was formed. Accordingly, when the lid 3 and the component body 2 are molded, the same material is used for the injection molding, so that an expensive two-color molding machine does not need to be used, and an inexpensive general-purpose injection molding machine having one cylinder is used. Thus, the hinge-shaped component 1 in which the lid 3 and the component main body 2 are relatively rotatably connected via the hinge portion 4 can be formed.

(2) In the present embodiment, first, the lid 3 was formed by injection-molding a molten polyacetal resin. Next, when the injection timing was different from that at the time of injection molding of the lid 3, the component main body 2 was molded by injection molding the same molten polyacetal resin as the lid 3. Here, if the injection timing is different, the polyacetal resin does not adhere to each other even if it melts at the same temperature, so that the lid 3 and the component body 2 do not adhere to each other. Therefore, the hinge-shaped component 1 in which the lid 3 and the component main body 2 are relatively rotatably connected via the hinge portion 4 can be formed.

(3) In the present embodiment, the hinge-shaped part 1 with the shaft part 5b of the part main body 2 fitted in the hole 6b of the lid 3 is manufactured. That is, the hinge-shaped part 1 does not need to be assembled after molding because the lid 3 and the component main body 2 are connected to each other via the hinge part 4 so as to be relatively rotatable. Can be. Therefore, the manufacturing process can be simplified, and the hinge-shaped part 1 can be provided at low cost.

(4) In the present embodiment, the second
The first support portion 6 of the lid 3 sandwiches the distal end portion 5a of the support portion 5.
Was formed. Therefore, when forming the shaft portion 5b having the same strength, it is easier to introduce the resin into the hole 6b when two short shaft portions 5b are formed than when one long shaft portion is formed. The shaft portion 5b can be easily formed.

(5) In the present embodiment, the mold 9 is composed of a fixed mold 9a and a movable mold 9b. After the lid 3 is injection-molded, the movable mold 9b is opened together with the lid 3 to form a mold. After rotating the movable mold 9b around the axis X by 180 degrees, the movable mold 9b was clamped to join the fixed mold 9a and the movable mold 9b, and the component body 2 was injection-molded. Therefore, it is easy to move the lid 3 integrally with the movable mold 9b, and the lid 3 can be easily sent to the injection molding step of the component body 2.

(6) In the present embodiment, while the lid 3 of the hinge-shaped part 1 is injection-molded, another hinge-shaped part 1 is simultaneously formed.
Was molded by injection molding. Thereafter, the component body 2 of the hinge-shaped part 1 is injection-molded and at the same time the next hinge-shaped part 1 is formed.
Was molded by injection molding. Here, the polyacetal resin was injected from one cylinder of the injection molding machine to simultaneously form the lid 3 and the component body 2. Therefore, since the polyacetal resin for the lid 3 and the component body 2 is injected from one cylinder, the molding conditions (temperature, pressure, etc.) for molding the lid 3 and the component body 2 are the same. As a result, the lid 3 and the component body 2 can be maintained with a certain quality.

Further, while manufacturing the lid 3 of the hinge-shaped part 1,
The component body 2 of another hinge-shaped component 1 was manufactured at the same time. That is, it is possible to perform a so-called setting in which different shapes are molded in the same mold.

The embodiment of the present invention may be modified as follows. In the above embodiment, the materials of the lid 3 and the component body 2 are polyacetal resin, but PA (polyamide resin), P
If injection timings such as BT (saturated polyester resin) are different, crystalline resins that do not adhere to each other even when melted at the same temperature may be used. In this case, the effects described in (1) to (6) in the embodiment can be obtained.

In the above embodiment, the hinge 3 is a molded product having a movable portion in which the lid 3 and the component body 2 are relatively rotatably connected via the hinge 4. The molded article and the secondary molded article may be a slide part as a molded article having a movable part slidably connected via a connecting part. In this case, a hole or a groove is formed in the primary molded product, and a slide member that slides along the hole or the groove is provided in the secondary molded product. In such a case, (1) to (3), (5),
The effect described in (6) is obtained.

Further, in the above embodiment, the movable mold 9
b is rotatable about the axis X, but the fixed mold 9a
May be configured to be rotatable about the axis X. In this case, after the lid 3 is injection-molded, the movable mold 9b is opened. Then, the fixed mold 9a is rotated by 180 degrees about the axis X. Thereafter, the movable mold 9b is clamped to join the fixed mold 9a and the movable mold 9b, and the component body 2 is injection-molded. In such a case, the effects described in (1) to (4) and (6) in the embodiment can be obtained.

Furthermore, in the above embodiment, the hinge-shaped part 1 was manufactured by rotating the movable mold 9b to injection-mold the component body 2 after the lid 3 was injection-molded. It is good also as a structure which can manufacture the hinge-shaped part 1 without rotating. That is, the mold 9 has a first cavity 10 and a second cavity 11, so long as the resin does not enter the first cavity 10 when the lid 3 is manufactured.

For example, a cavity in which the first cavity 10 and the second cavity 11 communicate with each other via a position corresponding to the hinge 4 is formed in a mold, and the slide core 13 is disposed at a position corresponding to the hinge 4. Then, at the time of molding the lid 3, the lid 3 having the hole 6b is injection-molded by disposing a separation wall for preventing the resin from entering the first cavity 10. Next, after the slide core 13 was retracted from the hole 6b and the separation wall was removed, injection molding of the component main body 2 was performed, and the shaft portion 5b of the component main body 2 was inserted into the hole 6b of the lid 3. Form into a state. In this case, in addition to the effects described in (1) to (4) and (6) in the embodiment, the size of the mold can be reduced, and the operation of rotating the movable mold 9b can be performed. The effect that it becomes unnecessary is obtained.

In the above-described embodiment, the lid 3 and the component body 2 are molded by one mold 9, but the mold for molding the lid 3 and the mold for molding the component body 2 are separately provided. Alternatively, the component body 2 may be molded in a state where the lid 3 is incorporated in a mold for molding the component body 2. In this case, in addition to the effects described in (1) to (4) in the embodiment, the size of the mold can be reduced, and the operation of rotating the movable mold 9b is not required. The effect is obtained.

Further, in the above embodiment, the hinge-shaped part 1 is constituted by the lid 3 as a primary molded part and the component body 2 as a secondary molded part. However, the hinge-shaped part 1 is a part as a primary molded part. It may be composed of the main body 2 and the lid 3 as a secondary molded product. In this case, a hole is provided in the distal end portion 5a of the second support portion 5 of the component body 2, and the distal end portion 6a of the first support portion 6 of the lid 3 is provided.
Is provided with a projection. In this case, the effects described in (1) to (6) in the embodiment can be obtained.

Next, technical ideas other than those described in the claims which can be grasped from the embodiment and other examples will be described below together with their effects. (1) In the method for manufacturing a molded article having a movable portion according to claim 1 or 3, the mold is composed of a fixed mold and a movable mold, and after injection molding of the primary molded article, the movable mold is formed. Open the mold with the primary molded product, rotate the movable mold around the axis, then clamp the movable mold, join the fixed mold and the movable mold, and inject the secondary molded product It is characterized by being molded. Therefore, according to the invention described in (1), it is easy to move the primary molded article integrally with the movable mold, and the primary molded article can be easily sent to the injection molding step of the secondary molded article. it can.

(2) In the method of manufacturing a molded article having a movable part according to any one of claims 1 to 3, the first support of the primary molded article is sandwiched by the second support of the secondary molded article. The parts are arranged. Therefore, according to the invention described in (2), when forming the protrusions having the same strength, it is better to form two short protrusions than to form one long protrusion so that the resin in the hole is formed. Because it is easy to be introduced,
An effect is obtained that the protrusion of the second support portion of the secondary molded product is easily formed.

[0043]

As described in detail above, according to the first to third aspects of the present invention, the primary molded product and the secondary molded product can be formed by an inexpensive general-purpose injection molding machine without using an expensive two-color molding machine. It is possible to mold a molded article having a movable portion connected to the molded article via a connecting portion so as to be relatively movable.

According to the fourth aspect of the present invention, it is possible to provide a molded product having a movable portion at low cost.

[Brief description of the drawings]

FIG. 1 is a perspective view of a hinge part.

FIG. 2 is a schematic sectional view in a mold.

FIG. 3 is a schematic cross-sectional view of a molded state of primary and secondary molded products.

FIG. 4 is a schematic cross-sectional view when the mold is opened after forming the primary and secondary molded products.

FIG. 5 is a schematic sectional view when the movable mold is inverted.

FIG. 6 is a schematic cross-sectional view when the movable mold is clamped after the movable mold is inverted to join the movable mold and the fixed mold.

FIG. 7 is a partial schematic cross-sectional view of a primary molded product in a molded state.

FIG. 8 is a partial schematic cross-sectional view of a secondary molded article in a molded state.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Hinge-shaped part as a molded product with a movable part, 2 ... Component body as a secondary molded product, 3 ... Lid as a primary molded product,
4 Hinge as connection part 5 Second support 5b Shaft as protrusion 6 First support 6b Hole 9 Mold and cavity for secondary molded product 1st cavity as a cavity, 11... 2nd cavity as a primary molded product cavity
Cavity, 13 ... Slide core as core member.

Claims (4)

[Claims] 1. A method of manufacturing a molded article having a movable part in which a primary molded article (3) and a secondary molded article (2) are relatively movably connected via a connecting part (4), When molding the primary molded product (3), the core member (13) is arranged at a position corresponding to the connecting portion (4) in the cavity (11) for the primary molded product formed in the mold (9). When the primary molded product (3) having the hole (6b) in the first support portion (6) is injection-molded, and the secondary molded product (2) is molded, the core member (13) is attached to the primary molded product (3). After retreating from the hole (6b) of the molded article (3), the secondary molded article (2) is subjected to injection molding with the same material as the primary molded article (3), and the secondary molded article (2) is formed. Forming the projection (5b) of the second support portion (5) into the hole (6b) of the first support portion (6) of the primary molded product (3). Method for producing a molded article having a movable portion to symptoms. 2. A method of manufacturing a molded article having a movable part in which a primary molded article (3) and a secondary molded article (2) are relatively movably connected via a connecting part (4), (1) After molding the primary molded product (3) in which the hole (6b) is formed in the support portion (6), the first molded product (3)
The support part (6) is set in a state where it is arranged in the cavity (10) for the secondary molded product formed in the mold (9), and the secondary molding is performed using the same material as the primary molded product (3). Injection molding of the product (2) is performed, and the second support portion (5) of the secondary molded product (2) is formed.
The protrusion (5b) of the first support (6) of the primary molded product (3)
Forming a molded product having a movable portion, wherein the molded product is formed so as to be fitted into the hole (6b). 3. The method of manufacturing a molded article having a movable part according to claim 1, wherein when the primary molded article (3) is molded, a molten crystalline resin is injection-molded. When the secondary molded article (2) is molded, the same molten crystalline resin as the primary molded article is injection-molded when the injection timing is different from the injection molding time of the primary molded article. Method for manufacturing molded products with parts. 4. A manufacturing method of a molded article having a movable part according to any one of claims 1 to 3, wherein the primary molded article (3) and the secondary molded article (2) are connected to each other. 4) a molded product having a movable portion connected so as to be relatively movable via a primary molded product (3) side of the coupling portion (4).
b) is formed, and a projection (5b) is formed on the side of the secondary part (2) made of the same material as the primary part (3) of the connecting part (4). A molded product having a movable part, wherein the projection (5b) is fitted into the hole (6b).