KR101339032B1 - A double injection mould having sliding cores for reinforcing structural weak parts in a mould - Google Patents

Abstract

According to the present invention, a sliding core is provided in the mold to reinforce structural weak parts in the mold, and the reinforced portion forms a primary cavity in which the primary product is molded, and when injection molding the secondary product, And a double injection mold having a sliding core capable of forming a secondary cavity in which a secondary product is molded. The double injection mold according to the present invention includes a primary upper mold with a primary nozzle, a secondary upper mold with a secondary nozzle, and a lower mold, and the lower mold is closed with the primary upper mold 1 A double injection mold for molding a secondary product, and the lower mold is closed with the secondary upper mold to form the secondary product. The lower mold includes a sliding core, and when the primary upper mold and the lower mold are mold closed, The sliding core of the lower mold is moved so that the primary upper mold is closed with the lower mold to form a primary cavity in which the primary product is formed, and when the lower mold is again closed with the secondary upper mold, the lower mold The sliding core is retracted to form a secondary cavity in which the secondary product is molded. In addition, the structurally weak part of the primary upper mold forming the mating surface and the lower mold is reinforced, and the reinforced portion of the primary upper mold is inserted into the space after the sliding core is moved to form a primary cavity. do.

Description

Double injection mold with sliding core to reinforce structural weak points in mold {A DOUBLE INJECTION MOULD HAVING SLIDING CORES FOR REINFORCING STRUCTURAL WEAK PARTS IN A MOULD}

The present invention relates to a double injection mold for injection molding the primary product, and then injection molding the secondary product on the primary product, and more particularly, a sliding core is installed in the mold to remove structural weak parts in the mold. The reinforcement part forms a primary cavity in which the primary product is molded, and when injection molding the secondary product, a sliding core capable of forming a secondary cavity in which the secondary product is molded is formed. It has a double injection mold having.

In general, injection molding involves injecting and filling a molten resin at a proper temperature and speed into a cavity in a mold having a product shape, and then cooling the mold after a certain amount of time. The molded product is taken out by molding.

In this case, double injection molds are frequently used for injection molding composite products having different types of resins or parts with different colors, and turn-table type and rotary type for double injection molds. There are a variety of die slide injection (DSI type), etc. In FIG. 1, a double injection mold of a turntable type is schematically illustrated to explain the double injection molding.

As shown in FIG. 1, the double injection mold of the turntable type includes a primary upper mold 10 having a primary nozzle 11 at a primary side, and a secondary side having a secondary nozzle 21 at a secondary side. An upper mold 20, and between the primary upper mold 10 and the secondary upper mold 20, the lower mold 30 consisting of the primary lower mold 31 and the secondary lower mold 32 Included. The primary lower mold 31 and the secondary lower mold 32 are formed symmetrically with each other, and may be rotated 180 degrees by a turn table.

Thus, as shown in (a), the primary molten resin is injected into the primary cavity between the primary upper mold 10 and the primary lower mold 31 through the primary nozzle 11 to form a primary When the product is molded, and as shown in (b), when the primary upper mold 10 and the primary lower mold 31 are opened, the primary molded product is attached to the primary lower mold 31. , The lower mold 30 is rotated 180 degrees by the turn table. Then, as shown in (c), the primary lower mold 31 is closely closed with the secondary upper mold 20 to form a secondary cavity for forming the secondary product. In order to mold the secondary product, the secondary molten resin having different physical properties or colors from the primary molten resin is formed between the secondary upper mold 20 and the primary lower mold 31 through the secondary nozzle 21. The secondary product is molded by injection into the secondary cavity, and at the same time, in the primary side mold, the primary side molten resin is rotated 180 degrees through the primary side upper mold 10 and the secondary side lower mold through the primary side nozzle 11. Injection is made into the primary cavity formed between the 32 to form the primary product. Then, as shown in (d), the molds are again opened and at the secondary mold side, the primary product and the secondary product are integrated and the finished product is taken out, and the lower mold 30 is again rotated by the turntable. It is also rotated to repeat the above process. Due to the double injection mold, it is possible to shorten the production time of the product, to produce a large amount of products in a uniform quality in a short time, and to obtain high productivity.

On the other hand, the mold joining surface of the mold contacts the upper mold and the lower mold during injection molding, and sets an area in which the molded product is molded.The molding area and the fitting angle of the molding surface are the type of resin, the injection molding condition, and the injection machine tone. It depends on the number of tons and the like. In general injection mold, it is possible to set the mold area and mold angle as much as necessary, but in the double injection mold, the part corresponding to the joint surface where the primary product is in contact with the secondary product is the mold during the primary injection. It should be used as the mating surface of, and the secondary injection is subject to the constraint that the secondary product should be used as the molding surface. Due to these constraints, molds are manufactured without sufficient mold area and angle of fitting in double injection molds, resulting in poor quality of the product during mass production, and abrasion, deformation, Due to breakage, there is a problem that causes a serious increase in cost and productivity.

The above description has been made using the turntable type double injection mold as an example, but the same applies to other double injection molds such as a rotary type and a die slide injection type.

The present invention was created to solve the above problems,

It is an object of the present invention to provide a double injection mold capable of designing a mating surface of a mold having a sufficient mating area and a mating angle regardless of the shape of the joining surface of the primary product and the secondary product.

Another object of the present invention is to provide a double injection mold that can sufficiently reinforce structurally even if a structurally weak part occurs in the mold due to the shape of the joint surface of the primary product and the secondary product.

In order to achieve the above object, the double injection mold according to the present invention includes a primary upper mold with a primary nozzle, a secondary upper mold with a secondary nozzle, and a lower mold, the lower In the double injection mold in which the mold is closed with the primary upper mold to mold the primary product, and the lower mold is closed with the secondary upper mold to form the secondary product, the lower mold includes a sliding core, When the primary upper mold and the lower mold are closed, the sliding core of the lower mold is moved to form the primary cavity in which the primary upper mold is closed with the lower mold to form a primary product. ; When the lower mold is again closed with the secondary upper mold, the sliding core of the lower mold is in situ to form a secondary cavity in which the secondary product is molded.

In addition, the double injection mold is reinforced by the structurally weak part of the primary upper mold forming a mating surface and the lower mold, the reinforced portion of the primary upper mold is inserted into the space portion after the sliding core is moved primary The cavity can be formed.

Preferably, when the primary upper mold and the lower mold are opened, the sliding core is in the original position, and the sliding core includes an elastic member, and the sliding core is positioned by the elastic member on the forming surface of the secondary product. Is preferably deflected to Here, the elastic member may be a spring.

On the other hand, the primary upper mold and the secondary upper mold includes a cam core, respectively, when the primary upper mold and the lower mold is closed, the sliding core is moved by the cam core of the primary upper mold, When the lower mold and the secondary side upper mold are closed, the sliding core is fixed to the position of the molding surface of the secondary product by the cam core of the secondary side upper mold, and the sliding during injection molding of the secondary product. The core is not pushed, and the cam core of the primary upper mold, by completely moving the sliding core of the lower mold before the primary upper mold and the lower mold is completely closed, the primary upper mold And the sliding core of the lower mold is preferably formed so as not to collide.

In the double injection mold according to the present invention, it is possible to design a mold joining surface of a mold having a sufficient joining area and a joining angle, regardless of the shape of the joining surfaces of the primary and secondary products, and the primary and secondary products. Because of the shape of the joint surface of the structurally vulnerable part in the mold even if it can be sufficiently reinforced structurally.

FIG. 1 is a diagram illustrating a double injection mold of a turntable type to explain double injection molding. Referring to FIG.
2 is a view showing an example of a finished product molded using a double injection mold.
3 is a view showing only the primary product of the finished product of FIG.
Figure 4 shows the structural weaknesses of the lower mold and the primary upper mold, forming the primary product.
FIG. 5 shows the reinforcement of the structural weaknesses of the lower mold with the sliding core and the primary upper mold forming the primary product.
6 is a view showing a process in which the sliding core is moved while the primary upper mold and the lower mold are closed to mold the primary product.
FIG. 7 is a view illustrating a process of mold closing of a secondary upper mold and a lower mold to mold a secondary product.

Hereinafter, specific details of embodiments of the present invention will be described with reference to the drawings. The present invention is not limited thereto, and may be implemented in various forms by those skilled in the art to which the present invention pertains. The scope of the invention is defined by the claims.

As an example, Figure 2 shows a finished product molded by using a double injection mold, (b) is a state in which the product of (a) is upside down. In FIG. 3, only the primary product portion of the finished product of FIG. 2 is shown, wherein the primary product 1 has a stage 1a, and the secondary product 2 has a stage 2a. The secondary product 2 is configured to extend in contact with the left and right sides of the primary product 1 including the stepped portion 2a. Here, the primary product 1 and the secondary product 2 may be composed of resins having different physical properties or colors.

1 and 2, the primary product 1 is molded between a primary side mold, ie, a primary upper mold 10 and a primary lower mold 31, and then the primary lower mold. The 31 is rotated 180 degrees to be closed with the secondary upper mold 20 to form the secondary product 2. At this time, the secondary product 2 should be molded in succession in contact with the side of the primary product (1). That is, the primary lower mold 31 is closed with the secondary upper mold 20 to form the secondary product 2 so as to form a secondary cavity C2 in which the side of the primary product 1 extends ( It should have the same shape in the lateral direction of the primary product 1 so that it can be formed (see FIG. 7).

Referring to FIG. 3, the primary product 1 of FIG. 2 is shown, wherein the primary product 1 is molded between the primary side mold, ie, the primary upper mold 10 and the primary lower mold 31. In order to achieve this, the side 1b including the stepped portion 1a of the primary cavity C1 (see FIG. 6) in which the primary product 1 is molded must be closed by the primary upper mold 10. . In other words, the side face 1b of the primary product 1 should be a mating surface. On the other hand, when the primary side lower mold 31 is rotated by 180 degrees with the primary product 1 attached to mold the secondary product 2, and closed with the secondary upper mold 20, the primary The side 1b of the product 1 should be the forming surface of the secondary product 2 so that the secondary product 2 can be contacted and subsequently formed.

FIG. 4 is a view showing structural weaknesses of the lower molds 31 and 32 and the primary upper mold for forming the primary product. FIG. 4A shows the primary product 1 in the lower molds 31 and 32. ) Is shown, the lower mold (1) in order for the side 1b of the primary product 1 to be in contact with the secondary product 2, that is, to be the forming surface of the secondary product 2. In order to mold the end portions 1a of the products 31 and 32, the end portions 31a and 32a which extend along the cross section of the primary product side surface 1b should be formed, and the primary product 1 The side 1b of the primary product 1 must be sealed by the primary upper mold 10 as a mating surface in order for the) to be molded. A part of the structure of the primary upper mold 10 for sealing the side 1b of the primary product 1 is shown in (b), as shown in the figure, the ends of the lower molds 31 and 32. In order to be inserted into the ridges 31a and 32a to seal the side 1b of the primary product 1, a stepped protrusion 10a must be formed in the primary upper mold 10. However, such protrusions 10a are structurally fragile and can be easily worn or broken, resulting in a poor quality of the product. It is to be understood that in practice, the hatched side 10b of (b) is in close contact with the opposite side of the hatched side 1b of (a) (not shown in figure).

In order to solve this problem, a double injection mold according to the present invention, in which the sliding core 40 is mounted on the lower molds 31 and 32, is illustrated in FIG. 5 by way of example. ) Shows the state with the lower molds (31, 32) in place to form the forming surface of the secondary product (2), (b) shows that the sliding core 40 is moved back from the position (C) shows a part of the primary upper mold (10) forming a primary cavity (C1) to be molded with the lower mold (31, 32), the primary product 1 is molded have.

As shown in FIG. 5A, in the lower molds 31 and 32, the sliding core 40 is mounted, and in the end portions 31a and 32a of the lower molds 31 and 32, When injecting the secondary product 2, the primary cavity C1 on which the primary product 1 is molded and the secondary cavity C2 on which the secondary product 2 is molded (upper and lower part in the drawing) sliding core ( As the 40 is connected, it forms the forming surface of the secondary product 2. However, in the injection molding of the primary product 1, the sliding core 40 moves back and forth at the above-mentioned (a) degree, and in the empty space 41 after the sliding core 40 moves, ( C) The protrusion 10d of the primary upper mold 10 shown in the drawing is inserted, and the side surface 10c hatched in the drawing forms a mating surface with the lower molds 31 and 32 to form the primary cavity C1. Seal the sides. By doing so, it is possible to structurally strengthen the structurally weak part as shown in FIG. 4B.

FIG. 6 is a view illustrating a process in which the sliding core 40 moves while the primary upper mold 10 and the lower molds 31 and 32 are closed to mold the primary product 1. As shown in the figure, the sliding core 40 is biased to the left in the drawing by a spring 42 made of metal. The spring 42 may be replaced with other elastic bodies. The cam core 50 may be fixedly attached to the primary upper mold 10. In this case, the reference numerals for the same components are represented only in (A). Referring to (b), when the primary upper mold 10 is lowered, the cam core 50 of the primary upper mold 10 enters the groove 40a of the sliding core 40, thereby sliding the core 40. Start to move to the right on the drawing. (C) also shows that the primary upper mold 10 is further lowered, so that the sliding core 40 is moved to the right as much as possible. At this time, the height "H" of the straight portion of the cam core 50 is larger than "h" indicated on the protrusion 10d of the primary upper mold 10, so that the protrusion 10a of the primary upper mold 10 slides. It is important to avoid colliding with the core 40. (D) also shows a state in which the primary upper mold 10 is completely lowered, and closed with the lower molds 31 and 32. In the empty space 41 after the sliding core 40 is moved, It can be seen that the protrusion 10a of the vehicle upper mold 10 is inserted. Thus, a primary cavity C1 is formed between the primary upper mold 10 and the lower molds 31 and 32, and a molten resin is injected into the primary cavity C1 so that the primary product 1 is formed. Molded.

In FIG. 7, after the primary product 1 has been molded, the primary upper mold 10 and the lower molds 31 and 32 are opened, and the primary product 1 is attached to mold the secondary product. The lower molds (31, 32) is a view showing the process of closing the secondary upper mold (20). Here, the sliding core 40 is closely biased to the left side in the drawing by the spring 42, and the shape of the cam core 60 of the secondary upper mold 20 is the cam core of the secondary upper mold 20 Even if 60 enters the groove 40a of the sliding core 40, the sliding core 40 is formed not to move. As shown in Fig. 3 (c), when the secondary upper mold 20 and the lower molds 31 and 32 are closed to form a secondary cavity C2 in which the secondary product 2 is molded, the molten resin The cam core 60 of the secondary upper mold 20 is formed to closely press the sliding core 40 to the left side in the drawing so that the sliding core 40 is not pushed to the right side in the drawing due to the injection pressure.

Although the above description has been mainly described as a turntable type double injection mold as an example, as mentioned above, the present invention is not only a turntable type double injection mold, but also other double injection mold such as a rotary type and a die injection type. The same can be applied to.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, And it is also within the scope of the present invention.

1: Primary Product 1a: Section of Primary Product
1b: Side of Primary Product 2: Secondary Product
2a: Second part of secondary product 10: Primary upper mold
10a: projection 10b: side
10c: side 10d: protrusion
11: primary nozzle 20: secondary upper mold
21: secondary nozzle 30: lower mold
31: Primary lower mold 31a: Primary part of lower mold
32: lower secondary mold 32a: lower stage of secondary lower mold
40: sliding core 40a: groove
41: empty space 42: spring
50: cam core 60: cam core
C1: Primary Cavity C2: Secondary Cavity

Claims (7)

A primary upper mold with a primary nozzle, a secondary upper mold with a secondary nozzle, and a lower mold, wherein the lower mold is closed with the primary upper mold to form a primary product, and again In the double injection mold in which the lower mold is closed with the upper mold of the secondary side to mold the secondary product,
The lower mold includes a sliding core, and the structurally weak portion of the upper upper mold forming the mold surface with the lower mold is reinforced, and when the primary upper mold and the lower mold are closed, the lower mold A sliding core is moved and a reinforced portion of the primary upper mold is inserted into a space portion after the sliding core is moved to form a primary cavity in which a primary product is formed;
And when the lower mold is closed with the secondary upper mold, the sliding core of the lower mold is in situ, thereby forming a secondary cavity in which the secondary product is molded.
delete The method of claim 1,
When the primary side upper mold and the lower mold is opened, the double injection mold, characterized in that the sliding core is in place.
The method of claim 1,
The sliding core includes an elastic member, characterized in that the sliding core is biased by the elastic member to the position of the molding surface of the secondary product.
5. The method of claim 4,
Double injection mold, characterized in that the elastic member is a spring.
The method of claim 1,
Each of the primary upper mold and the secondary upper mold includes a cam core, and when the primary upper mold and the lower mold are closed, the sliding core is moved by the cam core of the primary upper mold. When the lower mold and the secondary side upper mold are closed, the sliding core is fixed to the position of the molding surface of the secondary product by the cam core of the secondary side upper mold, and the sliding during injection molding of the secondary product. A dual injection mold, characterized in that the core is not pushed.
The method according to claim 6,
The cam core of the primary upper mold moves the sliding core of the lower mold completely before the primary upper mold and the lower mold are completely closed, so that the sliding core of the primary upper mold and the lower mold does not collide. Double injection mold, characterized in that not formed.

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