KR101221408B1 - Injection mould with stacked type vent core - Google Patents

Abstract

The present invention relates to an injection molding mold configured to smoothly discharge the gas in the cavity, that is, the air and the gas of the molten resin, when the molten resin is injected into the cavity inside the mold, and according to the present invention, the laminated vent core is mounted. The injection molding die may include: a fixed side template into which molten resin is injected; A movable side template in close contact with the fixed side template to form a cavity of a product shape; And at least one stacked vent core mounted in the fixed side template or the movable side template to introduce gas in the cavity through a plurality of gaps formed at one side, and discharge the introduced gas through the other side. A plurality of vent pieces are stacked, and a plurality of gaps are formed between the stacked plurality of vent pieces, so that gas in the cavity can be smoothly discharged to the outside of the mold.

Description

Injection molding mold with stacked vent cores {INJECTION MOULD WITH STACKED TYPE VENT CORE}

The present invention relates to an injection molding mold, and more particularly, when a molten resin is injected into a cavity having a product shape formed in the mold, gas in the cavity, that is, air and gas contained in the molten resin are smoothly discharged to the outside of the mold. It relates to a configured injection molding mold.

In general, an injection molding mold basically includes a fixed side template and a movable side template, and when the movable side template is brought into close contact with the fixed side template (hereinafter referred to as "mold closed"), between the fixed side template and the movable side template, One or more cavities (hereinafter referred to as cavities) in which the molten resin is injected to form the product are formed, and the molten resin is molded by pressing the molten resin into the cavity, and when the molded product is cooled and solidified, the movable side template is formed. After being separated from the stationary template (called "opening"), the molded product is extracted. In order to produce a high-quality product, it is necessary to smoothly discharge the gas generated in the cavity and the molten resin to the outside of the mold when the molten resin is injected into the cavity. In particular, Air and gas degassing at the weld line portion is essential.

In particular, resins such as PMMA, PC, PPA, PPS, PA66, and PA6 should be injected at high speed. Even in this case, air and gas in the cavity should be discharged smoothly.

Particularly, when a high transparency is required or a product containing a large amount of glass components is used to form a product, such as a product molded from a light guide plate or a PC material, To the outside.

In a typical injection molding mold, there is a slight venting gap between the parting line where the stationary side and the movable side template meet each other for the discharge of gas, ie air and gas, in the cavity. Air vents are vented around the outside of the venting gaps to allow air and gas to be discharged.By increasing the venting gap between the stationary side and the movable side template, a burr (forming along the parting line) There are many occurrences of debris formed around the product, a problem that requires reworking of the product after molding, and a problem that waste of resin increases. Therefore, the venting gap is processed as small as possible, for example, about 10-30 μm, depending on the type of resin, especially the viscosity of the resin. However, depending on the shape of the product, it is difficult not only to process such bending gaps and venting grooves, but also to select and process the venting gaps according to the type of resin, in particular, the viscosity of the resin, and to produce such venting gaps and venting grooves. Due to the blockage, there is a problem that should be cleaned periodically the venting site.

Alternatively, particle cores may be installed under the cavity and a gap of about 0.01-0.05 mm may be generated on the sidewall of the particle core, or air and gas may be discharged through a minute gap between the ejector pin and the ejector pin. It is difficult to be installed to correspond to the weld line part or the place where the trap of air or gas is generated, and in particular, in the case of resin, which has a lot of gas, or formed of a light guide plate or PC material When molding a product that requires a high degree of transparency, such as a product, there is a problem that product defects frequently occur due to gas.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems, and when the molten resin is injected into the cavity inside the mold, an injection molding mold equipped with a laminated vent core which smoothly discharges the gas in the cavity, that is, the air and the gas of the molten resin, is provided. To provide.

Still another object of the present invention is to reduce or eliminate defects caused by gas, even in the case of resins with high gas generation or when molding transparent products.

Another object of the present invention is to forcibly discharge air and gas in the cavity when injecting the molten resin into the cavity inside the mold, so that the molten resin is evenly filled in all parts of the cavity even when the shape of the injected product is complicated. And to completely discharge the gas to improve the quality of the injection product.

In order to achieve the above object, the present invention, the stationary side template in which molten resin is injected; A movable side template in close contact with the fixed side template to form a cavity having a product shape; And at least one stacked vent core mounted in the fixed side template or the movable side template to introduce gas in the cavity through a plurality of gaps formed at one side and discharge the introduced gas through the other side. The stacked vent core is formed by stacking a plurality of vent pieces, and a plurality of gaps are formed between the stacked vent pieces so that the gas in the cavity can be discharged to the outside of the mold. An injection molding mold is provided.

Here, the vent piece includes an upper gap portion and a bottom contact portion, wherein the gap portion has a thickness smaller than that of the contact portion, and a vent groove through which gas passes is formed in an intermediate portion where the gap portion and the contact portion meet. When the plurality of vent pieces are stacked, a plurality of gaps are formed, and the plurality of gaps and the vent grooves communicate with each other, such that gas entering through the plurality of gaps may be discharged through the vent grooves. desirable. In addition, it is preferable that through vents are formed in each of the vent pieces, and when the vent pieces are stacked, respective through holes communicate with each other, thereby facilitating the discharge of gas.

In addition, a gas passage may be formed in the injection mold to allow gas to be discharged to the outside of the mold from the laminated vent core, and the gas passage may be connected to a vacuum pump to force the gas in the cavity to be forced out. It is desirable to have.

Here, the vacuum pump is preferably operated by a timer.

On the other hand, the gap (gap) of the gaps formed between the plurality of the plurality of vent pieces is preferably about 0.01-0.05mm, so that gas is introduced but molten resin is not introduced.

In addition, the injection molding mold further comprises a rim core, it is preferable that the laminated vent core is mounted in the rim core.

In addition, the laminated vent core may be disposed at a weld line portion where molten resins injected into the cavity meet each other, and a place where a trap of air or gas is likely to occur.

On the other hand, the above-described laminated vent core can be used as a means for discharging impurities of semiconductor equipment or fine particles.

In addition, the above-mentioned laminated vent core can also be used as a means for injecting gas between minute gaps.

An injection molding mold equipped with laminated vent cores according to the present invention provides the following effects.

-It is possible to smoothly discharge the gas in the mold cavity, that is, air and gas, so that a good quality product can be formed.

-Gas defects can be reduced or eliminated even when resins with high gas generation or when molding transparent products. In particular, in the case of products requiring a high degree of transparency, such as a product formed from a light guide plate or a PC material, or when the product is molded using a material containing a large amount of glass components, the effect is more significant.

-There is no need to process fine gaps in the parting line between the stationary side plate and the moving side template, and when mass-producing products in the past, there is no need to periodically clean the fine gaps of the parting line. As a result, the production of the mold is easy and the molding operation can be continuously performed, thereby increasing the productivity.

When the molten resin is injected into the cavity inside the mold, the air and gas in the cavity are forcibly discharged so that the molten resin is evenly filled in all parts of the cavity even when the shape of the injected product is complicated, and the gas is completely discharged. , Can improve the quality of injection products.

-The vent core according to the present invention is applicable to all kinds of injection molding molds, and its application range is wide.

1 is a schematic cross-sectional view of an injection molding die equipped with stacked vent cores in accordance with the present invention.
Figure 2a is a plan view showing a state in which laminated vent cores are disposed on the lower surface of the cavity in the injection molding mold according to the present invention (when the molded product is in the form of a frame).
Figure 2b is a plan view showing a state in which the laminated vent cores are disposed on the lower surface of the cavity in the injection molding mold according to the present invention (when the molded product is in a flat form).
3 is a schematic perspective view of one vent piece constituting the stacked vent core according to the present invention.
4A is a plan view of one vent piece according to the present invention.
4B is a side view along line II of FIG. 4A.
4C is a cross-sectional view taken along the line II-II of FIG. 4A.
5 is a perspective view illustrating a state in which a plurality of vent pieces of FIG. 3 are stacked.
6 is a view illustrating some examples when the stacked vent core according to the present invention is mounted to the edge core.

Hereinafter, with reference to the accompanying drawings, it will be described in detail a preferred embodiment of the present invention.

In Fig. 1, a cross-section of an injection molding mold equipped with stacked vent cores according to the present invention is shown illustratively and schematically. In a typical injection molding mold, the stationary side mold includes a stationary side mounting plate 11, a stationary side template (also called a top plate) 12, and a stationary side core (also called an upper core) 13, which are fastened. It is fixedly connected to each other by a bolt or the like. The movable side mold 21 includes a movable side mounting plate 21, a movable side template (also called a lower plate) 22, a movable side core (also referred to as a lower core) 23, and a spacer block 24. It is included, these are fixedly coupled to each other by a fastening bolt or the like. Here, the fixed side core 13 and the movable side core 23 may be omitted. Thus, the stationary side template used herein should be interpreted as a component comprising the stationary side core, and the movable side template should also be interpreted as a component comprising the movable side core.

In addition, a locating ring 2 and a sprue bush 3 to which the nozzle (not shown) of the injection molding machine is connected are fixedly mounted to the stationary mold.

When the stationary side mold and the movable side mold are in close contact, a parting line is formed between the stationary side template 12 and the movable side template 22, and the movable side template 22 is connected to the stationary side template 12. When the mold is closely closed, a cavity 1 of a product shape is formed between the stationary side core 13 and the movable side core 23 in which a product is molded. Then, when the molten resin is injected from the nozzle (not shown) of the injection molding machine (in the direction of arrow "A" in the drawing), the molten resin is sprue bush 3, runner portion 4 and gate 5 When the molten resin is injected into the cavity 1 through the molten resin passage to form a product, and the molding in the cavity 1 is cooled and solidified, the fixed side mold and the movable side mold are separated, that is, opened and molded. The finished product comes out of the mold.

 When the molten resin is injected into the cavity 1, the resin is not evenly filled in the cavity 1 unless the gas generated in the air and the molten resin (herein referred to as gas) in the cavity 1 is smoothly discharged. Otherwise, a burn mark occurs in the molded product to produce a defective product. Therefore, in order to produce a high quality molded product, it is necessary to smoothly discharge the gas in the cavity 1, that is, the gas generated from the air and the molten resin, and in particular, the molten resin injected through the gate 5 is the cavity 1. The release of air and gas at the sites where they meet each other, i.e., the weld line, is very important. In particular, in the case of products requiring a high degree of transparency, such as a product formed of a light guide plate or a PC material, or when molding a product using a material containing a large amount of glass components, air and gas emissions are more important.

 In order to smoothly discharge the gas in the cavity 1 to the outside of the mold, in FIG. 1 and FIG. 2A, a laminated vent core according to an embodiment of the present invention is applied to a case in which a product having a frame shape having an empty central portion is molded. The gas passages 101 formed at the bottom of the cavity 1, in particular in the weld line portion or at the site where a trap of air or gas can be formed, are formed in the movable side core 23 and the movable side template 22. It is connected to the, and the gas in the cavity 1 is to be smoothly discharged to the outside of the mold. Here, the stacked vent core 100 is shown to be mounted in the rim core 121 (see FIG. 6) and fixed in the movable side core 23 by the fixing bolt 122, without the rim core 121. The stacked vent core 100 may be mounted directly in the movable side core 23. The stacked vent core 100 will be described in detail with reference to FIGS. 3 to 5.

In addition, the gas passage 101 formed in the mold may be connected to a vacuum pump to more actively discharge the gas in the cavity 1 to the outside of the mold.

At this time, the vacuum pump may be automatically controlled by a timer (timer) installed in the control panel of the injection molding machine.

On the other hand, reference numeral 27 is a blowout block, which is mounted on the movable side plate 22 so as to slide up and down, and when the mold is opened after the molded product in the cavity 1 is solidified, a separate hydraulic device (not shown) is provided. By this, the molded product in the cavity 1 can be pushed up and extracted from the movable side mold. In addition, in the spacer block 24 between the movable side mounting plate 21 and the movable side template 22, the ejector upper plate 25 and the ejector lower plate 26 are provided to be movable up and down, and the description thereof is omitted. Let's do it.

2a shows a case in which the product shape is a frame having an empty central portion, the stacked vent cores 100 according to the present invention are disposed below the cavity 1 (8 are arranged in the drawing), and FIG. 2b In the case where the product shape is a surface form such as a lamp cover, the stacked vent cores 100 according to the present invention are shown in a state disposed below the cavity (9 are arranged in the drawing), which is intended to help understanding In the drawings, the quantity and position of the laminated vent core 100 actually arranged will vary depending on the shape of the product and the type of resin, and it is particularly important to place the weld line portion or a place where traps of air or gas are likely to occur.

3 and 4a to 4c shows one vent piece 110 constituting the stacked vent core 100 according to an embodiment of the present invention, Figure 3 is a schematic perspective view of the vent piece, 4A is a plan view of the vent piece, and FIGS. 4B and 4C are side and cross-sectional views taken along the line II and the line II-II of FIG. 4A, respectively.

When a plurality of these vent pieces are stacked, a stacked vent core 100 according to an embodiment of the present invention, as shown in FIG. 5, is formed.

In one vent piece 110 shown in FIG. 3, the front surface 1111 in the upper portion (herein, referred to as “gap portion” because the gap is formed in the upper portion (117 of FIG. 5)) 111 is illustrated in FIGS. 4A through 4A. As shown in FIG. 4C, the upper portion (here the lower portion is in close contact with each other when the vent pieces are stacked and thus referred to as "close contact") is entered by "g" than the front surface 1121 in the upper portion (gap). The left and right side surfaces 1112 in the upper part 111 are also "g" larger than the left and right side surfaces 1122 in the lower part (close part) 112, so that the vent pieces 110 are stacked and edged. When mounted to the core (121 in FIG. 7) or the movable side core (23 in FIG. 1), the front and side surfaces of the upper portion (gap portion) 111 have as much gaps as there are gaps "g" (117 in FIG. 5). Is formed, gas in the cavity 1 may be discharged through the fine gaps 117.

Meanwhile, in the middle portion where the upper portion (gap portion) 111 and the lower portion (contact portion) 112 meet each other, as shown in FIGS. 3 and 4A to 4C, the front surface of the lower portion (contact portion) 112 is shown. And grooves 113 and 114 having a depth “a” are formed from the side surfaces, and as shown in FIG. 3, the groove 115 having a depth “a” is also formed on the front surface of the lower portion (contact portion) 112. (Herein, they are referred to as "vent grooves"). The fine gaps 117 and the vent grooves 113, 114, and 115 are in communication with each other, and when the vent core 100 having the vent pieces 110 stacked thereon is mounted in a mold, a gas passage formed in the mold (FIG. Through 101 of 1, gas in the cavity 1 can be discharged out of the mold.

Wherein the fine gap "g" is a very fine gap of about 0.01-0.05mm, so that only the gas can be introduced without entering the molten resin, and the depth "a" of the vent grooves is about 0.4-0.8mm It is preferable. As described above, the "g" value and the "a" value are very small, but it is understood that the drawings are exaggerated for clarity.

Although the cross-sections of the vent grooves 113, 114, and 115 of the vent piece 110 are illustrated in a rectangular shape in the drawing, they may be processed into various shapes such as a triangle or a semi-circle shape, and the shape of the vent piece 110 is shown. It may also be modified in various forms. In addition, in each of the vent pieces 110, as shown in FIGS. 4B and 4C, through holes 116 are formed, and when the respective vent pieces 110 are stacked, the respective through holes 116 communicate with each other. This may further promote the release of gas.

5 illustrates a state in which the vent pieces 110 are stacked according to an embodiment of the present invention. The stacked state forms one stacked vent core 100 according to the present invention. At least one of the laminated vent cores 100 is disposed in a mold according to the shape of a cavity having a product shape, and is particularly disposed at a weld line portion and a portion where a trap of air or gas may occur, such that a molten resin is disposed in the mold. When injected, the gas in the cavity can be smoothly discharged out of the mold.

6, these stacked vent cores 100 are mounted in different types of edge cores 121 so that the edge cores 121 are mounted in a fixed side template or a fixed side core, or a movable side template or a movable side core. Without the edge core 121, the stacked vent pieces 110, ie, the stacked vent core 100 itself, may be directly in the stationary side template or the fixed side core in the mold, or directly in the movable side template or the movable side core. It may be mounted. Although only two forms of the edge core 121 are illustrated in FIG. 6, these edge cores 121 may be modified in various forms according to the position and state of the stacked vent core 100.

The above-described laminated vent core 100 may be used in all fields of a mold for molding a plastic product, and may be used in an industrial field for discharging impurities of semiconductor equipment or fine particles.

Meanwhile, the stacked vent core 100 described above has been described as being used for the purpose of discharging gas, but may also be utilized in an industrial field in which gas is injected between minute gaps.

The above description has been described by way of example of the present invention, the present invention is not limited to this, and those skilled in the art to which the present invention pertains without departing from the technical spirit of the present invention claimed in the claims. Obvious modifications are possible and such modifications are within the scope of the present invention.

1: cavity 2: locating ring
3: sprue bush 4: runner part
5 gate 11 fixed side mounting plate
12: fixed side template (upper plate) 13: fixed side core (upper core)
21: movable side mounting plate 22: movable side template (lower plate)
23: movable side core (lower core) 24: spacer block
25: ejector top plate 26: ejector bottom plate
27: extraction block 100: stacked vent core
101: gas passage 110: vent
111: gap 112: close contact
113: front vent groove 114: side vent groove
115: vertical vent groove 116: through hole
117: fine gap 121: edge core
122: fixing bolt 1111: the front of the gap portion
1112: side of the gap portion 1121: front side of the contact portion
1122: close contact side

Claims (12)

A fixed side template into which molten resin is injected;
A movable side template in close contact with the fixed side template to form a cavity having a product shape;
And at least one stacked vent core mounted in the fixed side template or the movable side template to introduce and discharge gas in the cavity.
The stacked vent core is formed by stacking a plurality of vent pieces, and a plurality of gaps are formed between the stacked plurality of vent pieces to discharge gas in the cavity to the outside of the mold,
The vent piece includes an upper gap portion and a bottom contact portion, wherein a thickness of the gap portion is smaller than a thickness of the contact portion, and a horizontal vent groove is formed between the gap portion and the contact portion, When a plurality of vent pieces are stacked and a plurality of vent pieces are stacked, a plurality of minute gaps of 0.01 mm to 0.05 mm are formed so that the gas escapes and the molten resin does not flow in, and the plurality of gaps and the horizontal gaps are formed. Directional vent grooves and longitudinal vent grooves are in communication with each other, the gas entering through the plurality of gaps can be discharged to the outside of the mold through the vent grooves, injection molding mold equipped with a laminated vent core.
delete The method of claim 1,
Each of the vent pieces is provided with a through hole, and when the vent pieces are stacked, the respective through holes communicate with each other, so that gas is promoted.
The method of claim 1,
In the injection molding mold, a gas passage is formed so that gas can be discharged from the laminated vent core to the outside of the mold, injection molding mold equipped with a laminated vent core.
5. The method of claim 4,
The gas passage is connected to a vacuum pump, characterized in that the gas in the cavity can be forced out, injection molding mold equipped with a laminated vent core.
The method of claim 5,
And the vacuum pump is operated by a timer.
delete The method of claim 1,
The injection molding mold further comprises a rim core, characterized in that the laminated vent core is mounted in the rim core, injection molding mold equipped with a laminated vent core.
The method of claim 1,
The laminated vent core is disposed in the weld line (weld line) where the molten resin is injected into the cavity, it characterized in that the injection molding mold equipped with a laminated vent core.
A multilayer vent core that can be used as a means for discharging impurities in fine particles in a semiconductor device, wherein the multilayer vent core includes:
A plurality of vent pieces are stacked, a plurality of gaps are formed between the stacked plurality of vent pieces, to introduce and discharge impurities,
The vent piece includes an upper gap portion and a bottom contact portion, wherein a thickness of the gap portion is smaller than a thickness of the contact portion, and a horizontal vent groove is formed between the gap portion and the contact portion, A vertical vent groove is formed, and when a plurality of vent pieces are stacked, a plurality of gaps are formed, and the plurality of gaps, the horizontal vent grooves, and the vertical vent grooves communicate with each other, through the plurality of gaps. Stacked vent core, characterized in that the introduced impurities can be discharged through the vent grooves.
A laminated vent core that can be used as a means for injecting gas between minute gaps, the laminated vent core,
A plurality of vent pieces are stacked, a plurality of gaps are formed between the stacked plurality of vent pieces, injecting gas through the gaps,
The vent piece includes an upper gap portion and a bottom contact portion, wherein a thickness of the gap portion is smaller than a thickness of the contact portion, and a horizontal vent groove is formed between the gap portion and the contact portion, A vertical vent groove is formed, and when a plurality of vent pieces are stacked, a plurality of gaps are formed, and the plurality of gaps and the horizontal vent grooves and the vertical vent grooves communicate with each other, such that the vent grooves and the plurality of vent grooves are in communication with each other. Stacked vent core, characterized in that the gas can be injected through the gaps.
12. The method according to any one of claims 10 to 11,
Each of the vent pieces is provided with a through hole, and when the vent pieces are stacked, the respective through holes communicate with each other, so that the discharge of impurities or injection of gas is promoted.

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