KR20130119126A - Apparatus for injection molding comprising gas emitting means - Google Patents

Abstract

An injection molding apparatus having a gas exhaust means according to the present invention comprises: an injection unit having a fixed mold and a moving mold, and an injection for injecting a molten liquid as a molding material into the molding space when the molding space is formed in close contact with each other; And exhaust means including an exhaust runner for communicating the molding space with the outside in the fixed mold or the moving mold to discharge residual air in the molding space. As described above, the present invention, in the process of injection molding by injecting the molten liquid of the molding material into the molding space formed when the moving mold is in close contact with the fixed mold, the exhaust runner is configured to discharge the residual air existing in the molding space to the outside As a result, the quality of the injection molded product can be improved. Specifically, it is possible to prevent defects such as burn phenomenon, black streak phenomenon, etc. generated at the site where the air remains, and to prevent the overall quality degradation of the material and shape of the product generated by the residual air. In particular, it is possible to prohibit such a problem that the size, which is small in size, which has a greater influence on a complicated and precise product.

Description

Apparatus for Injection Molding Comprising Gas Emitting Means

The present invention relates to an injection molding apparatus, wherein the injection molding apparatus includes a gas exhaust means configured to discharge the residual air existing in the molding space to the outside.

In general, an injection molding apparatus is a device that obtains a product having a desired shape by injecting a molten resin in a high temperature state into a mold consisting of a fixed mold and a moving mold and cooling after a predetermined time.

A conventional injection molding apparatus will be described with reference to FIG. 1.

Conventional injection molding apparatus has a movable mold (1) to be moved by the operation of the cylinder (5), a fixed mold (2) in which the moving mold (1) is in close contact with the position fixed, and the fixed mold ( It consists of the injection 4 which inject | pours resin melt into the injection runner 2a of 2).

The movable mold 1 disposed on one side is moved to the other side by the operation of the cylinder 5, and when the rod 5a of the cylinder 5 extends, a driving link mounted at the end of the rod 5a (6), the upper cross link (7) sequentially connected to the drive link (6), the first connecting link (8), and the moving die plate (9) is moved to the other side, the moving die plate ( The moving mold 1 fixed to 9 is moved toward the fixed mold 2 of the other side.

As the moved mold 1 moves in close contact with the fixed mold 2, the space formed between the fixed mold 2 and the movable mold 1 is sealed by the fixed mold 2 and the movable mold 1. As a result, a closed molding space 3 for injection is formed. At this time, the molding space (3) is in communication with the injection runner (2a) of the fixed mold (2).

Then, when the resin melt is injected into the injection runner 2a of the stationary mold 2 by the injection 4, the resin melt is filled in the molding space 3, and when the proper time passes, the resin melt solidifies. After the moving mold 1 is moved to one side, the injection molded article is ejected to complete the injection molding.

In the conventional injection molding apparatus configured and operated as described above, the molten liquid is injected into the molding space 3 by injecting the molten liquid through the injection runner 2a through the injection 4. The existing air is discharged to the outside through the gap of the injection pin of the injection (4), at this time the air that does not come out will remain in the molding space (3).

In other words, the air remains at the point where air is difficult to escape, such as the depth of the product such as bosses, ribs and the weld portion.

In this way, when the flow rate of the air in the mold is slower than the inflow rate of the resin melt in the mold, and the air cannot be escaped, the remaining air is momentarily adiabatic and the resin burns out. Burn or black streak, a phenomenon in which black streaks occur in injection molded products. In addition to this, unmolded parts may be present, blistering may occur, weld line strength may be weakened, or surface gloss quality of the molded article may be deteriorated.

Along with this defect phenomenon, in terms of the quality of the product to be injection molded, there is a problem about the material and shape of the product generated by the residual air.

In particular, in the case of a small size, a complicated and precise product, the above problem is more affected.

Korea Patent Office Registered Patent Publication No. 10-0157226

The present invention has been made to solve the above problems, and an object thereof is to provide an injection molding apparatus having a gas exhaust means having an exhaust runner for discharging the residual air existing in the molding space to the outside. have.

In order to achieve the above object, the present invention provides a fixed mold and a moving mold to form a molding space, an injection unit having an injection for injecting a molten liquid as a molding material into the molding space; One side is connected to the molding space and the other side is an exhaust runner which is a passage formed in the stationary mold or the moving mold to be connected to the discharge flow path, and formed in the stationary mold or the moving mold, both ends are open and the other side of the exhaust runner is connected It provides an injection molding apparatus having a gas exhaust means comprising a; exhaust means consisting of a discharge flow path which is a passage connected to the flow generating means at one end.

In the above, the discharge flow passage is composed of a connecting portion connecting the two or more straight portion and the straight portion, the exhaust runner is connected to any one of the two or more straight portion, the straight portion that the exhaust runner is not connected to the exhaust runner to the discharge passage It is characterized in that it is located between the portion to be connected and the exhaust runner is connected to the molding space.

In the above, the exhaust flow path is characterized in that the venturi portion is formed in the portion connected to the exhaust runner.

In the above, the discharge flow path is formed as a tube on the outside, the end of the exhaust runner is characterized in that it is connected to the discharge flow path by an extension that is a pipe.

In the above, the exhaust runner is characterized in that it comprises a cooling portion formed to be spaced apart from the exhaust passage portion located between the portion connected to the exhaust runner and the exhaust runner is connected to the molding space.

In the above, the exhaust runner is characterized in that the cross section is reduced from the forming space to the end portion between the end portion.

In the above, the exhaust runner is characterized in that it has a bent portion between the end from the molding space.

In the above, the exhaust runner is characterized in that it comprises an expansion pipe portion having an increased cross-sectional area in which the melt flowing from the molding space solidifies at the end connected to the molding space.

In the injection molding apparatus having a gas exhaust means according to the present invention, the residual air existing in the molding space during injection molding by injecting a molten liquid, which is a molding material, into the molding space formed when the moving mold is in close contact with the stationary mold. As the exhaust runner is configured to discharge to the outside, it has an effect of increasing the quality of the injection molded product.

Specifically, it prevents defects such as burns, black streaks, unmolding, and blisterings that occur in areas where air remains, and at the same time, lowers the overall quality of the material and shape of products caused by residual air. It can prevent, and the strength of the weld line is improved.

In particular, it is possible to block the above problems, which have a larger impact on large products as well as small, complex and precise products in advance, and to allow the solution to flow to the expansion portion provided at the end of the exhaust loader. By solidifying in the pipe part can solve the unmolding problem, and there is an effect of determining the molding quality by the melt solidified in the expansion part.

1 is a view for explaining an injection molding apparatus according to the prior art,
Figure 2 is a schematic perspective view showing an injection molding apparatus having a gas exhaust means according to a preferred embodiment of the present invention,
3 is a perspective view showing a state in which a molding space is formed by moving a moving mold in close contact with a fixed mold in the injection molding apparatus including the gas exhaust means of FIG.
4 is an enlarged cross-sectional view illustrating a portion of an exhaust passage connected to an exhaust runner in the injection molding apparatus including the gas exhaust unit of FIG. 2;
FIG. 5 is a perspective view illustrating a discharge passage disposed outside in the injection molding apparatus including the gas exhaust unit of FIG. 2;
6 is an enlarged cross-sectional view of the exhaust runner in the injection molding apparatus including the gas exhaust means of FIG.
7 is a perspective view illustrating a process of discharging residual air in the injection molding process by the injection molding apparatus having the gas exhaust means of FIG.

In the injection molding apparatus having the gas exhaust means of the present invention, the injection molding unit is configured to inject the molten liquid, which is a molding material, into the molding space formed when the movable mold is in close contact with the stationary mold. The technical feature is that the exhaust runner is configured to discharge air to the outside. Residual air in the description of the present invention is a concept including the air remaining in the molding space and the gas generated from the melt.

Hereinafter, the present invention will be described in detail with reference to the drawings. In the description of the present invention, description of the cylinder 5, the link member, and the moving die plate, which are related to moving the moving mold, will be omitted.

Figure 2 is a schematic perspective view showing an injection molding apparatus having a gas exhaust means according to a preferred embodiment of the present invention, Figure 3 is a movable mold in the injection molding apparatus having a gas exhaust means of Figure 2 fixed mold Figure 4 is a perspective view showing a state in which a molding space is formed in close contact with, Figure 4 is an enlarged cross-sectional view showing a portion of the discharge passage connected to the exhaust runner in the injection molding apparatus having a gas exhaust means of Figure 2, Figure 5 Figure 6 is a perspective view showing that the discharge flow path is provided in the injection molding apparatus having a gas exhaust means of the outside, Figure 6 is an enlarged cross-sectional view showing the exhaust runner in the injection molding apparatus having a gas exhaust means of Figure 2, 7 is a perspective view illustrating a process of discharging residual air in the injection molding process by the injection molding apparatus having the gas exhaust means of FIG.

Referring to the drawings, the present invention is a fixed mold 30 and the movable mold 20 and the injection portion having an injection molding, the forming mold 40 is formed in close contact with each other, the fixed mold 30 or the movable mold 20 And exhaust means having an exhaust runner 60 therein. Injection is connected to the stationary mold (30).

The injection part is fixed to the fixed position 30, the movable mold 20 is moved to selectively contact with one surface of the fixed mold 30, the fixed mold 30 is connected to the movable mold 20 It consists of an injection (not shown) for injecting a molten liquid as a molding material into the molding space 40 formed in close contact with the fixed mold 30.

The injection mold is fixed to the fixed mold 30 and the movable mold 20 is moved in the injection portion, and the injection to inject a melt, such as a plastic resin solution into the main runner 31 of the fixed mold 30, the present invention Not limited by the above and any conventional configuration may be utilized, and furthermore, the specific configuration of the entire injection part is not limited by the present invention, of course.

In addition, the molten liquid, which is the molding material, may be any molding material for injection, such as not only a plastic resin melt but also a metal melt.

On the other hand, the molding space 40 is formed between the fixed mold 30 and the moving mold 20 is formed by moving the moving mold 20 in close contact with the fixed mold 30 in the injection molding.

As a specific example, the molding space 40 is formed with a molding groove in the fixed mold 30, the moving mold 20 is moved to the fixed mold 30 is a molding of the fixed mold 30 simply without a molding groove. Only a role of sealing the groove 30a may be performed.

On the contrary, the molding space 40 has a molding groove 20a formed in the moving mold 20, and the fixed mold 30 which is in close contact with the moving mold 20 is simply moved without a molding groove. It can only serve to seal the forming groove (20a) of (20).

By the way, in general, as having a certain degree of appearance on the front and rear or both sides of the product to be manufactured, forming grooves (20a, 30a) corresponding to the outer shape of the product is formed in each of the stationary mold 30 and the movable mold 20 Can be.

In addition, the molten liquid is injected and filled into the molding space 40 formed as described above, and at this time, the main runner, which is a passage through which the melt reaches the molding space 40, is also fixed mold 30 or a moving mold. 20 may be formed. In this case, the runner refers to a passage that is a passage through which the fluid injected by the injection flows into the molding space 40. In the drawing, the main runner 31 is formed in the stationary mold 30.

Here, as a representative example, as shown in FIGS. 2 to 7, forming grooves 20a and 30a are formed in the stationary mold 30 and the movable mold 20, respectively, and the main runner 31 is formed in the stationary mold 30. The exhaust means of the present invention will be described in detail on the premise that the injection part is formed.

The molding space 40 in the present specification means a space formed by molding grooves 20a and 30a formed in each of the fixed mold 30 and the moving mold 20 in close contact with each other, typically an injection molded product shape. Refers to the product forming space 40a, and further includes a connection runner 40b connected to the plurality of product forming spaces 40a from the main runner 31 when there are a plurality of product forming spaces 40a. do.

Accordingly, the exhaust runner 60 communicating with the molding space 40 may communicate with the product molding space 40a in the molding space 40 or may be in communication with the connection runner 40b. Of course, it may be connected to the main runner (31).

When the exhaust runner 60 is directly connected to the product forming space 40a, the exhaust runner 60 is connected to the site where the unmolding occurs, and the melt flows to the exhaust runner 60 connected to the unmolding part. An effect that can prevent the molding from occurring also occurs. An end portion of the exhaust runner 60 connected to the molding space 40 may be provided with an expansion pipe having an increased cross-sectional area. The exhaust runner 60 is connected to the site where the unmolding occurs, the expansion part is provided at the end, and the melt flows to the expansion part to solidify, thereby determining the molding quality by checking the solidified state in the expansion part after molding. can do.

As an example, in the drawings of the present invention, the exhaust runner 60 is configured to communicate at a point before branching from the main runner 31 to the plurality of product forming spaces 40a among the various points of the connection runner 40b. .

The exhaust runner 60 may be formed in the fixed mold 30 or the moving mold 20 to communicate with the molding space 40. As an exemplary embodiment, the exhaust runner 60 is formed in the fixed mold 30. Can be. A part of the end of the exhaust runner 60 may be formed as a recess in the stationary mold 30 or the movable mold 20, and may be formed as a passage when the stationary mold 30 and the movable mold 20 come into contact with each other. .

Such an exhaust runner 60 is a passage connected to the molding space 40 to one side and a discharge passage 70 to be described later to the other side, and serves as a flow path through which residual gas in the molding space 40 is discharged to the outside. do. The exhaust runner 60 may be formed in the stationary mold 30 or the movable mold 20.

In the conventional injection molding apparatus, as shown in FIG. 1, in the process of injecting the molten liquid into the injection runner 2a through the injection 4 and filling the molten liquid into the molding space 40, in the molding space 3. The existing air comes out to the injection pin gap of the injection (4), etc. At this time, the air that did not come out will remain in the molding space (3).

In other words, air remains at the point where air is hard to escape, such as deep parts of the product such as bosses, ribs, or weld parts. Thus, the air flows out due to the slow flow rate of air in the mold compared to the inflow rate of the melt. If it does not go out and remains, black streaks (black), which is a phenomenon in which residual air is momentarily compressed by adiabatic compression and the resin burns out, or black streaks are formed in the injection molded product streak), blistering, unmolding, and the strength of the weld line is reduced.

As such, in terms of the quality of the product to be injection molded, there is a problem about the material and shape of the product generated by the residual air.

In particular, in the case of a large product or a small size, a complex and precise product, the above problem has a greater effect. In order to prevent such a problem, in the present invention, an exhaust runner, which is a passage communicating with the molding space 40, is used. 60 is provided.

In addition, the exhaust means further includes a discharge passage 70 connected to the exhaust runner 60 as a flow passage of the outside air. The discharge passage 70 is a passage through which the outside air supplied from the flow generating means 80 flows, and has a structure in communication with the exhaust runner 60, thereby forming the molding space 40 through the exhaust runner 60. Provides exhaust force for residual air inside.

The discharge passage 70 is a passage connected to the other side of the exhaust runner 60 and may be formed in the stationary mold 30 or the moving mold 20. One side of the discharge passage 70 is connected to the flow generating means 80 through a pipe (not shown), the solenoid valve for opening and closing the flow between the flow generating means 80 and the discharge passage (70) ( 90). The flow generating means 80 may be a blower or a compressor having a function of supplying air to the discharge flow path 70. The solenoid valve 90 is electrically connected to a controller (not shown) to control the gas flow of the discharge flow path 70 by the user. Of course, in this case, the flow generating means 80 may also be electrically connected to the control unit and operated together with the solenoid valve 90.

The discharge passage 70 is a passage formed in the stationary mold 30 or the movable mold 20, both ends of which are opened, and a flow generating means 80 is connected to one side, between both ends of the discharge passage 70. The exhaust runner 60 is connected. The flow generating means 80 is connected to the discharge flow path 70 through a pipe.

As the discharge passage 70 flows outside air supplied by the flow generating means 80 therein, a relatively low pressure is formed in comparison with the molding space 40 in the stationary mold 30, and one side is molded. The other side is connected to the space 40 and the other side is sucked out of the remaining air in the molding space 40 through the exhaust runner 60 connected to the discharge flow path 70 to be discharged to the outside. Therefore, in the discharge passage 70, the outside air is supplied by the flow generating means 80 at one side, and the remaining air and the outside air supplied by the flow generating means 80 are discharged together at the other side.

The exhaust passage 70 may be preferably formed with a venturi portion 70a such that a negative pressure is formed at a portion where the exhaust runner 60 is connected. The venturi portion 70a is a portion having a smaller cross-sectional area than the other portions in the discharge passage 70 and has a structure such that a flow rate of gas flowing therein becomes relatively faster.

By the structure of the venturi portion 70a configured to gradually narrow the cross-sectional area in the inner passage of the discharge passage 70 and widen again, the flow rate of the gas flowing through the portion is increased, whereby the gas in the portion The pressure acting on it will be lowered.

As the negative pressure lower than atmospheric pressure is formed in the venturi part 70a of the discharge passage 70, the residual air in the molding space 40 is more effectively sucked and discharged to the outside.

Accordingly, when the molten liquid is injected into the molding space 40, the flow generating means 80 and the solenoid valve 90 are operated to supply external air to the discharge passage 70, thereby remaining air in the molding space 40. It can be discharged to the outside efficiently.

On the other hand, the above-described discharge passage 70 may be formed as a passage in the fixed mold 30 or the moving mold 20, or may be formed as a tube on the outside.

That is, the discharge passage 70 may be formed in the stationary mold 30 or the moving mold 20. As an example, as shown in FIGS. 2 to 4, the discharge passage 70 may be provided by forming a passage in the stationary mold 30. Can be.

In another embodiment, the discharge flow path 70 may be disposed outside without being formed in the fixed mold 30 or the moving mold 20, as shown in FIG. 5, a predetermined distance from the fixed mold 30. It can be formed by a tube member such as a tube on the outside.

Of course, when the discharge passage 70 is disposed outside, the exhaust runner 60 may further include an extension part 60a that is a pipe connected to the discharge passage 70.

In this way, the discharge passage 70 is a flow passage of the outside air and has a structure in communication with the exhaust runner 60, it is only configured to provide the exhaust force for the remaining air of the molding space 40, its position and specific shape Of course, the present invention is not limited to the present invention, and any position and shape may be taken.

'자형으로 형성될 수 있다. 상기에서 2개 이상의 직선부를 연결하는 연결부는 굴곡된 형태로 형성할 수도 있고 직선으로 형성할 수도 있다. 상기 2개 이상의 직선부는 서로 평행하게 형성될 수도 있고, 경사지게 형성될 수도 있다. 2개 이상의 직선부가 경사지게 형성될 때 서로 예각을 가지도록 형성될 수 있다.The discharge passage 70 may be formed to have one or more connecting portions and two or more straight portions, and thus the discharge passage 70 may have a 'U' shape or '

'Can be shaped. The connecting portion connecting two or more straight portions in the above may be formed in a curved form or may be formed in a straight line. The two or more straight portions may be formed parallel to each other or may be formed to be inclined. When two or more straight portions are formed to be inclined, they may be formed to have an acute angle with each other.

Residual gas in the forming space 40 is also discharged to the exhaust runner 60 connected to the discharge passage 70, but since the melt is also flowed through the exhaust runner 60, the melt that has flowed to the exhaust runner 60 rapidly. The portion of the discharge passage 70 downstream from the portion where the exhaust runner 60 is connected to the discharge passage 70 is adjacent to the exhaust runner 60 such that the exhaust runner 60 is connected to the discharge passage 70 so as to solidify at the inflow to prevent the excessive melt from being discharged. It is formed to be located.

The exhaust runner 60 includes an expansion pipe having an increased cross-sectional area at an end connected to the molding space 40. The melt flowing to the exhaust runner 60 is solidified in the expansion part provided at the end of the exhaust runner 60 and no longer flows along the exhaust runner 60.

The discharge flow path 70 is formed in a 'U' shape, the exhaust runner 60 is connected to one straight portion (hereinafter referred to as a 'first straight portion'), and the other straight portion (hereinafter referred to as 'first') 2 straight line portion ") is positioned between the portion where the exhaust flow path 70 and the exhaust runner 60 are connected and the portion where the exhaust runner 60 is connected to the molding space 40, so that the exhaust runner 60 It may be formed so as to be adjacent to the discharge passage (70). The discharge flow path 70 is positioned adjacent to the expansion pipe of the exhaust runner 60, that is, the distance between the discharge flow path 70 and the expansion pipe of the exhaust runner 60 is made as small as possible. As the outside air flows, the expansion pipe is effectively cooled, so that the melt solidifies in the expansion pipe.

'자형으로 형성되는 경우, 양측 중 어느 일측 직선 부분(이하에서 '제1 직선 부분'이라 한다)에 배기런너(60)가 연결되도록 하고, 나머지 직선 부분(이하에서 '제2 직선 부분'이라 한다)은 배출유로(70)와 배기런너(60)가 연결되는 부분과 배기런너(60)가 성형공간(40)에 연결되는 부분 사이에 위치되도록 하여, 배기런너(60)가 배출유로(70)에 인접하게 위치하도록 형성할 수 있다.Discharge flow path (70)

'When formed in a shape, the exhaust runner 60 is connected to any one straight portion (hereinafter referred to as a' first straight portion ') of both sides, and the remaining straight portion (hereinafter referred to as a' second straight portion '). ) Is positioned between the portion where the discharge passage 70 and the exhaust runner 60 are connected and the portion where the exhaust runner 60 is connected to the molding space 40, so that the exhaust runner 60 is the discharge passage 70. It may be formed so as to be adjacent to.

In addition, the exhaust runner 60 may be provided to be positioned adjacent to the discharge passage 70, and may be provided with a cooling unit 60b which is spaced apart from the discharge passage 70 and surrounds the discharge passage 70. When the discharge flow path 70 is formed in a 'U' shape, the cooling unit 60b of the exhaust runner 60 extends while surrounding the second straight portion of the discharge flow path 70 to form the discharge path 70. 1 It is connected by a straight part.

The cooling unit 60b serves to block the subsequent discharge of the melt in the molding space 40 while the residual air is discharged into the discharge passage 70.

By forming the discharge flow path 70 and the exhaust runner 60 adjacent to each other, or by providing the cooling runner 60b in the exhaust runner 60, the low temperature discharge flow path 70 and the exhaust runner 60 through which the outside air flows. Heat exchange between the two) is further activated to effectively cool the exhaust runner (60).

In other words, in the process of discharging the remaining air in the molding space 40 to the outside through the exhaust runner 60 and the discharge passage 70, the molten liquid filled in the molding space 40 may be discharged accordingly, the solution In order to prevent this excessive discharge, the cooling unit 60b is configured.

To this end, the cooling unit 60b has a structure that surrounds the discharge flow path 70, thereby cooling the heat exchanger 60 by heat exchange with the discharge flow path 70 having a relatively low temperature due to the flow of external air. The molten liquid flowing along can be solidified.

Of course, when the discharge passage 70 is disposed outside, the section surrounding the discharge passage 70 in the extension portion 60a of the exhaust runner 60 corresponds to the cooling unit 60b.

In addition, the exhaust runner 60 may be configured to increase the flow resistance of the melt flowing from the molding space 40 to prevent the discharge of the melt as described above.

As a preferred example, as shown in FIG. 6, the exhaust runner 60 may have a structure in which a cross-sectional area is reduced between an end portion and a portion connected to the molding space 40 while extending from the molding space 40. The exhaust runner 60 may be formed in a shape in which the cross-sectional area decreases from the portion connected to the forming space 40 toward the end portion.

As described above, as the cross-sectional area of the exhaust runner 60 gradually decreases, the cross-sectional area through which the melt can flow while maintaining the residual air exhaust function is reduced, thereby making the flow of the viscous melt more difficult.

In addition, the exhaust runner 60 may have a curved shape while extending from the forming space 40. Since the flow of the molten liquid is not smooth due to the curved structure which makes the direction change several times instead of the linear direction, the flow resistance of the molten liquid can be further increased.

The cross section of the exhaust runner 60 may be formed in a circular shape, or may be formed in a polygonal shape such as a triangle or a square to increase flow resistance.

Of course, the specific shape of the curved structure of the exhaust runner 60 is not limited by the present invention as long as it has a proper shape within a range that does not interfere with other components.

Then, the process of discharging air remaining in the molding space 40 when filling the molten liquid 11 as a molding material in the molding space 40 will be described with reference to FIG. 7.

First, prior to filling the molten liquid 11 in the molding space 40, the closed molding space 40 is formed by bringing the moving mold 20 into close contact with the fixed mold 30.

Next, as the injection (not shown) is operated to inject the melt 11, which is a molding material, through the main runner 31, the melt 11 is filled in the molding space 40.

As such, when the molten liquid 11, which is a molding material, is filled in the molding space 40 or before filling, the external air flows in the discharge passage 70. For this purpose, the solenoid valve 90 is controlled to be opened and flow is generated. Activate (80).

In the process of filling the molten liquid 11 into the molding space 40, the remaining air remaining in the molding space 40 is discharged to the outside through the exhaust runner 60 and the discharge passage 70.

Next, when the molten liquid 11 is filled in the molding space 40, the flow generating means 80 is stopped and the solenoid valve 90 is closed-controlled.

In this process, the molten liquid 11 filled in the molding space 40 may flow from the molding space 40 to the outside through the exhaust runner 60, in which case the exhaust runner 60 surrounding the exhaust flow path 70. As the molten liquid 11 introduced into the exhaust runner 60 is cooled and solidified by the cooling unit 60b, the discharge to the outside is blocked.

According to the present invention constituted as described above, in the process of injecting a molten liquid, which is a molding material, into the molding space 40 formed when the movable mold 20 is in close contact with the fixed mold 30, the molding space 40 is formed. As the exhaust runner 60 is configured to discharge residual air existing therein, the quality of the injection molded product may be improved.

Specifically, it is possible to prevent defects such as burn phenomenon, black streak phenomenon, etc. generated at the site where the air remains, and to prevent the overall quality degradation of the material and shape of the product generated by the residual air.

In particular, it is possible to prohibit such a problem that the size, which is small in size, which has a greater influence on a complicated and precise product.

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. It is to be understood that various changes and modifications may be made without departing from the scope of the appended claims.

20: moving mold 30: fixed mold
20a, 30a: molding groove 31: main runner
40: molding space 40a: product molding space
40b: connection runner 60: exhaust runner
60a: extension part 60b: cooling part
70: discharge passage 70a: venturi portion
80: flow generating means 90: solenoid valve

Claims (8)

An injection unit including an injection mold for injecting a molten liquid, which is a molding material, into the fixed mold 30, the movable mold 20, and the molding space 40 to form the molding space 40; One side is connected to the molding space 40 and the other side is a passage formed in the fixed mold 30 or the movable mold 20 to be connected to the discharge flow path 70 and the fixed mold 30 Or an exhaust means formed on the movable mold 20 and having an end flow path 70 formed at both ends thereof and connected to the other side of the exhaust runner 60 and connected to the flow generating means 80 at one end thereof. Injection molding apparatus having a gas exhaust means characterized in that. According to claim 1, The discharge flow path 70 is composed of a connecting portion connecting two or more straight portion and the straight portion, the exhaust runner 60 is connected to any one of the two or more straight portion, exhaust runner 60 ) Is not connected to the straight line gas exhaust means characterized in that the position between the exhaust runner 60 is connected to the discharge flow path 70 and the exhaust runner 60 is connected to the molding space 40 Injection molding apparatus provided. The injection molding apparatus according to claim 1, wherein the exhaust passage (70) has a venturi portion (70a) formed at a portion to which the exhaust runner (60) is connected. According to claim 1, wherein the discharge passage 70 is formed as a tube on the outside, the end of the exhaust runner 60 is connected to the discharge passage 70 by an extension portion (60a) which is a pipe. Injection molding apparatus comprising a means. The exhaust runner of claim 2, wherein the exhaust runner 60 is disposed between a portion where the exhaust runner 60 is connected to the discharge flow path 70 and a portion where the exhaust runner 60 is connected to the molding space 40. Injection molding apparatus having a gas exhaust means characterized in that it comprises a cooling unit (60b) formed so as to be spaced apart from the passage (70). 7. The gas exhaust means according to any one of claims 1 to 6, wherein the exhaust runner 60 has a portion in which the cross-sectional area decreases from end to end between the molding space 40. Injection molding machine. 7. The injection molding apparatus according to claim 6, wherein the exhaust runner (60) has a bent portion between the end portions of the molding space (40). 3. The gas exhaust means according to claim 2, wherein the exhaust runner (60) has an expansion section having an increased cross-sectional area through which the molten liquid flowing from the molding space (40) solidifies at an end connected to the molding space (40). Injection molding apparatus having a.

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