KR20120095180A - A nozzle appratus with double valve pins for hot runner system of injection mould - Google Patents

Abstract

PURPOSE: A dual-valve pin nozzle device for a hot runner system of an injection forming mold is provided to prevent the interference of a valve pin and a melting resin by forming a valve pin passage and a resin pin passage in a nozzle separately. CONSTITUTION: A dual-valve pin nozzle device for a hot runner system of an injection forming mold comprises a fixed valve pin(110), a moving valve pin(120), a valve pin driving unit(100), and a nozzle(200). The fixed valve pin is coupled with the mold of a fixed part and projected to the inside of a cavity(400). The fixed valve pin is inserted in the longitudinal hole of the moving valve pin. The moving valve pin is moved along the fixed valve pin. The valve pin driving unit moves the moving valve pin up and down. The nozzle comprises a valve pin passage(212) and a resin passage(213). The fixed valve pin and the moving valve pin are inserted in the valve pin passage. The melting resin is supplied into the cavity.

Description

ANOZZLE APPRATUS WITH DOUBLE VALVE PINS FOR HOT RUNNER SYSTEM OF INJECTION MOULD}

The present invention relates to a nozzle device of a hot runner system of an injection molding die, and more particularly, a double valve pin installed at a lower part of a manifold of a hot runner system to inject molten resin into a cavity in a mold. It relates to a nozzle device having a.

In the case of a cold runner system in injection molding, the molten resin in the runner portion, which is the flow path of the molten resin in the mold, is cooled and solidified together with the molten resin in the cavity for forming the mold product. Taken out together, the runner portion is removed from the blown molded product and the removed runner portion is recycled again. This may result in waste of the resin and increases in the number and time of production processes. In contrast, the hot runner system is a system in which the molten resin of the runner portion is heated to about 200 ° C. to 400 ° C. by using electricity or steam to maintain the molten state at all times. As a result, productivity and ease of production automation, and the product has the advantages of improving the quality of the situation is a lot of research and development.

1 shows a conventional hot runner system as described above. Briefly, a clamping plate 1 is installed at an upper portion thereof, and a spacer plate 2 is disposed at a lower portion thereof. The holding plate 3 and the cavity plate 4 are sequentially installed, and the manifold block 5 is installed in the space between the clamping plate 1 and the holding plate 3. And all of them are fixed and fastened by a fastening bolt or the like to form a fixed side mold. In addition, a plurality of nozzles 20 are mounted below the manifold block 5, and electric or steam heaters 34 for heating are installed around the manifold block 5 and the nozzle 20.

When the movable mold 10 (not shown in detail in the drawing) comes into close contact with the fixed mold, that is, the cavity plate 4, a cavity 11 for forming a product is formed, and the molten resin is formed at the lower end of the nozzle 20. The valve pin hole 12 is injected into the cavity 11 through a gate.

Meanwhile, a passage 21 elongated in the longitudinal direction of the nozzle is formed in the central portion of the body of the nozzle 20, and the valve pin 33 is inserted in the passage 21 to enable vertical movement. The valve pin drive unit 30 for operating the valve pin 33 is installed on the nozzle 20, the valve pin drive unit 30 includes a cylinder 31 and a piston 32, the piston ( 32, the upper end of the valve pin 33 is fixed. Thus, when compressed air is supplied through the lower air passage 35, the piston 32 and the valve pin 33 fixed thereto are moved upwards, so that the valve pin hole 12 at the lower end of the nozzle 20, namely, When the cavity of the cavity is opened and compressed air is supplied through the upper air passage 36, the valve pin 33 moves downward to block the valve pin hole 12 and the gate of the cavity. Although the valve pin drive unit 30 is described herein as being operated by compressed air, it may be hydraulically or electrically operated instead of compressed air.

On the other hand, the upper side of the clamping plate (1) is equipped with a locating ring (6) supplied with molten resin from an injection molding machine (not shown), the molten resin supplied through the locating ring (6) is a manifold block ( 5 is injected into the cavity 11 through the runner portion 13 and the molten resin passage in the nozzle 20. At this time, the valve pin 33 is moved upward by the valve pin drive unit 30. When the injection of the resin is completed, as described above, the valve pin 33 moves downward by the valve pin drive unit 30 to block the valve pin hole 12 in communication with the cavity 11, that is, the gate of the cavity. Will block.

However, the existing valve pin 33 is one-piece, so that when the valve pin 33 is moved upward to open the valve pin hole 12, that is, the gate of the cavity, molten resin is injected into the cavity through the gate. In this case, the molten resin is often not uniformly filled in the cavity. Particularly, when injection molding a rotating product, it is very important that the molten resin is uniformly filled. If the density of the molded product is not uniform, an unbalanced force is generated during rotation of the product, causing vibration and noise, and assembling. This is because the finished product will not function properly.

In addition, in the conventional nozzle 20, the inner diameter of the passage 21 of the valve pin 33 formed in the body of the nozzle is larger than the outer diameter of the valve pin 33, so that the molten resin passes through the inner wall of the passage 21 and the valve pin. (33) Through the outer wall to be injected into the cavity 11, the operation of the valve pin 33 may not be smooth due to the molten resin around the valve pin 33, and, as time passes, the valve pin ( 33) There is a problem in that the molten resin sticks around and the passage of the molten resin decreases, and the nozzle and the valve pin driving unit must be periodically disassembled and washed.

The present invention was created to solve the problems of the prior art as described above, and an object of the present invention is to provide a nozzle apparatus in which molten resin can be uniformly filled in a cavity.

Another object of the present invention is to prevent the operation of the valve pin from interfering with the molten resin, and to provide a nozzle device having a good flow of the molten resin.

Still another object of the present invention is to provide a nozzle device that is easy to process.

The double valve pin nozzle apparatus of the present invention for solving the above problems, the upper end is fixed to the fixed side mold, the lower end fixed valve pin protruding in the cavity in which the product is molded; A moving valve pin having a longitudinal hole in which the fixed valve pin is inserted therein, the movable valve pin being mounted to be movable up and down along the fixed valve pin; A valve pin driving unit for moving the moving valve pin up and down; And a nozzle having a valve pin passage through which the fixed valve pin and the moving valve pin are inserted, and a resin passage through which the molten resin is supplied into the cavity, wherein the molten resin is injected into the cavity through the resin passage of the nozzle. And the gate is opened or closed by the moving valve pin.

It is preferable that at least one resin passage of the nozzle is formed separately from the valve pin passage. Wherein the nozzle comprises a nozzle body; And a nozzle head assembled to a lower end of the nozzle body, wherein the valve valve passage is formed in a lengthwise direction of the nozzle body so that the moving valve pin can move up and down, and the valve body is formed in the nozzle body. At least one resin passage through which the molten resin can flow is formed in the longitudinal direction of the nozzle body, and the lower portion of the nozzle head is concentric with the valve pin passage so that the movable valve pin can be opened or blocked. A valve pin hole penetrated concentrically is formed, and the valve pin passage, the at least one resin passage, and the valve pin hole are preferably passed through each other.

On the other hand, the resin passage of the nozzle and the valve pin passage are formed in common, the fixed valve pin and the moving valve pin is placed in the resin passage of the nozzle, the resin passage inner diameter of the nozzle is the outer diameter of the moving valve pin Larger, the molten resin may be injected into the cavity through the inner wall of the resin passage of the nozzle and the outer wall of the moving valve pin.

In addition, the valve pin drive unit may be operated by compressed air, may be operated by an electromagnet, may be operated by hydraulic pressure.

The double valve pin nozzle apparatus according to the present invention provides the following effects.

-The molten resin is uniformly filled in the cavity, which enables injection molding of high grade rotating body products.

-When injection molding a rotating product, the center of the product is held at the center and the injection is possible.

-By separately forming the valve pin passage and the melt passage in the nozzle, interference between the valve pin and the melt can be prevented.

-By separating and processing the nozzle body and the nozzle head, and processing in a straight line without cross taper processing on the resin passage in the nozzle, the processing is easy and the precision of processing can be improved.

-Since the resin passage in the nozzle is inclined and there is no part where step is generated, it is possible to prevent discoloration by preventing the retention of resin.

1 is a view of a conventional injection molding hot runner system.
FIG. 2 is a schematic view showing an open state of a double valve pin nozzle apparatus according to an exemplary embodiment of the present invention.
3 is a schematic diagram showing a closed state of a gate of a double valve pin nozzle apparatus according to a preferred embodiment of the present invention.
Figure 4 is a cross-sectional view before assembly of the assembled nozzle of the double valve pin nozzle apparatus according to a preferred embodiment of the present invention.
Figure 5 is a cross-sectional view after the assembly of the assembled nozzle of the double valve pin nozzle apparatus according to a preferred embodiment of the present invention.
6 is a cross-sectional view taken along line II of FIG. 5.
FIG. 7 is a schematic diagram illustrating an open state of a nozzle device having a double valve pin mounted to an existing nozzle according to another embodiment of the present invention.
FIG. 8 is a schematic view illustrating a state in which a gate is closed as a nozzle device having a double valve pin mounted to an existing nozzle according to another embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, it will be described in detail with respect to the double valve pin nozzle apparatus used in the hot runner system of the injection molding mold according to the present invention, which is illustrative and does not limit the present invention.

Figure 1 is for the prior art and has been described in the above [Background Art], so it is omitted here.

2 and 3 is a preferred embodiment of the present invention, schematically shows a double valve pin nozzle device equipped with a double valve pin in the assembled nozzle formed separately from the valve pin passage, the passage of the molten resin, FIG. 2 shows an open state of the gate, and FIG. 3 shows a closed state of the gate.

2 and 3, the double valve pin nozzle apparatus according to the present invention includes a fixed valve pin 110, a moving valve pin 120, a valve pin driving unit 100, and a nozzle 200. It is made to include.

The upper end 111 of the fixed valve pin 110 is fixedly fastened to the fixed side mold, and the lower end 112 protrudes in the cavity 400 in which the product is molded.

A fixed valve pin hole 123 in the longitudinal direction is formed in the inner center of the moving valve pin 120, and the fixed valve pin 110 is inserted into the fixed valve pin hole 123. Thus, the moving valve pin 120 is mounted to be movable up and down along the fixed valve pin (110).

The valve pin driving unit 100 includes a piston 130 and a cylinder 140, is installed on the upper side of the moving valve pin 120, the upper end 121 of the moving valve pin 120 on the piston 130. ) Is fixed and fastened. The lower air passage 151 and the upper air passage 152 are connected to the cylinder 140, and when compressed air is supplied to the lower air passage 151, the piston 130 moves upward, and the compressed air passes through the upper air passage. When supplied to the furnace 152, the piston 130 moves downward. When the piston 130 moves upward, the movable valve pin 120 fixed thereto is moved upward, and the molten resin is injected into the cavity 400 by opening the gate portion of the cavity 400, and the molten resin When the injection of the air is completed, the compressed air is supplied to the upper air passage 152 to move the piston 130 and the moving valve pin 120 fixed to it downward, thereby closing the gate portion of the cavity 400.

In this case, since the fixed valve pin 110 is fixedly fastened to the fixed side mold, the fixed valve pin 110 is always maintained in place regardless of the operation of the valve pin driving unit 100, and the lower end 112 of the fixed valve pin 110 is It protrudes outward through the lower end 122 of the moving valve pin 120 and protrudes into the cavity 400 through the gate of the cavity 400. The protruding length is preferably about 5 to 10 mm, but this may vary depending on the size of the molded article. Thus, when the molten resin is injected into the cavity 400, due to the fixed valve pin 110 protruding into the cavity 400, the molten resin is evenly injected into the cavity 400 to provide a product of uniform density It can be molded. This is particularly important when injection molding rotatable products.

Here, although the valve pin drive unit 100 has been described as operating by compressed air, it may be operated by an electromagnet or hydraulic.

On the other hand, the nozzle 200 is tightly coupled to the lower manifold block 160, the molten resin injected from the injection machine (not shown) through the runners in the manifold block 160, the resin in the nozzle 200 Through the passage 213, it is injected into the cavity 400 through the gate of the cavity 400. In the nozzle 200, a valve pin passage 212 into which the fixed valve pin 110 and the moving valve pin 120 are inserted, and a resin passage 213 through which molten resin is supplied into the cavity 400 are formed. 2 and 3, as a preferred embodiment of the present invention, the valve pin passage 212 and the resin passage 213 are separately formed so that the double valve pin is applied to the assembled nozzle communicating under the nozzle 200. A double valve pin nozzle arrangement is shown. Here, although one resin passage 213 is shown in the figure, two or more resin passages 213 may be formed according to the amount of molten resin injected per unit time.

However, in the double valve pin of the present invention, a valve pin is installed in a conventional nozzle (see FIG. 1), that is, a passage of the molten resin, that is, a passage of the molten resin and a valve pin passage, and the inner wall of the molten resin passage and the valve pin It can also be applied to nozzles through which melt flows through gaps between outer walls. This is illustrated in FIGS. 7 and 8.

On the other hand, Figures 4 to 6 are shown for the above-described assembled nozzle 200, Figure 4 is a cross-sectional view before the assembled nozzle 200, Figure 5 is a prefabricated nozzle 200 This is a cross-sectional view after assembling, and FIG. 6 is a cross-sectional view taken along the line II of FIG.

As shown in FIGS. 4-6, the assembled nozzle 200 includes a nozzle body 210 and a nozzle head 220, which are processed separately and then assembled to form the nozzle 200. do. As a result, in the conventional integrated nozzle, in order to form the resin passage separately from the valve pin passage, cross taper processing in which the resin passages meet inclined to each other inside the nozzle body is required. It is easy to process because it is not necessary, and the precision of the degree of processing can be improved. In addition, various problems associated with cross tapering of inclined resin passages intersecting with each other, for example, the tip diameter of the nozzle tip valve pin hole becomes larger than the valve pin diameter, the problem of lowering the machining accuracy, the inclined intersection of the inclined resin passage It is possible to solve the problem of step difference.

In the inner center of the nozzle body 210, a straight valve pin passage 212, which allows the moving valve pin 120 to move up and down to block the injection of the molten resin into the cavity in the mold in which the product is molded, has a nozzle body ( Resin passage 213 is formed in the longitudinal direction of the nozzle body 210 perpendicular to the cross-section of the 210, and slightly apart from the valve pin passage 212, the molten resin flows in the longitudinal direction of the nozzle body 210, Is formed. Unlike the valve pin passage 212, the resin passage 213 in the longitudinal direction is shown to be slightly inclined in the cross section of the nozzle body 210, but similarly to the valve pin passage 212 in the cross section of the nozzle body 210. It may be formed vertically.

Although one resin passage 213 is illustrated in the drawing, the number of resin passages 213 may be increased according to the injection amount of the molten resin.

On the other hand, the lower portion of the nozzle head 220, that is, the front end of the nozzle head, concentric with the valve pin passage 212 of the nozzle body 210, that is, coincident with the center line of the valve pin passage 212, the moving valve pin ( A valve pin hole 222 through which the flow of the molten resin can be opened or blocked by the 120 is formed therethrough, and a recessed portion 221 is formed at a portion coupled to the nozzle body 210 to form a nozzle body corresponding thereto. The protrusion 211 of the 210 may be tightly inserted into the recess 221, and the nozzle body 210 and the nozzle head 220 may be assembled to each other.

In addition, the lock pin grooves 214 and 224 are formed on the edge surfaces 216 and 226 in contact with the nozzle body 210 and the nozzle head 220 to correspond to each other, so that the lock pins may be formed in the lock pin grooves 214 and 224. 231 may be fitted to assemble the nozzle body 210 and the nozzle head 220. Coupling pin holes 215 and 225 are formed in the protrusion 211 and the recess 221 to correspond to each other, so that the protrusion 211 of the nozzle body 210 is recessed 221 of the nozzle head 220. After inserting it in, a separate coupling pin (232 of FIG. 6) is inserted and fixed firmly.

Although the lock pins 231 and the coupling pins 232 are shown to be fastened by two, respectively, in the drawings, the number thereof may vary depending on the size of the nozzle and the like. In addition, the coupling of the nozzle body 210 and the nozzle head 220, the protrusion 211 of the nozzle body 210 is inserted into the depression 221 of the nozzle head 220 is coupled by the coupling pin 232 Although shown, other methods may also be used, such as flange coupling, screw coupling, and the like.

On the other hand, as shown in Figures 4 to 6, the inner surface of the nozzle head 220 that meets the resin passage 213 of the nozzle body 210, as shown in the figure to smooth the flow of the molten resin It is preferable that the same rounding part 223 is formed. In addition, in order to facilitate the flow of the molten resin in the protrusion 211 of the nozzle body 210, it is preferable that the rounded protrusion 217 as shown in the figure is formed. Here, although the rounding part 223 and the rounding protrusion 217 are illustrated as curved surfaces having curvatures, the rounding part 223 and the rounding protrusions 217 may be formed in an inclined straight line without curvature for convenience of processing.

On the other hand, Figure 7 and 8, as another embodiment of the present invention, it is shown that the double valve pin of the present invention is applied to the existing nozzle that the passage of the molten resin and the valve pin passage in common, Figure 7 The gate of the cavity 400 is open, and FIG. 8 shows the gate of the cavity 400 is closed.

Here, the nozzle 300 is integrated, and a passage 310 having an inner diameter larger than the outer diameter of the moving valve pin 120 is formed inside the nozzle body. The fixed valve pin 110 and the moving valve pin 120 are installed in the passage 310, and the moving valve pin 120 moves up and down according to the operation of the valve pin driving unit 100 in the passage 310. Will be

As shown in FIG. 7, in a state in which the moving valve pin 120 is moved upward by the operation of the valve pin driving unit 100, the molten resin that enters through the runner in the manifold block 160 is passed through the passage 310. A gap between the inner wall and the outer wall of the moving valve pin 120 flows and is injected into the cavity 400 through the gate of the cavity 400. In this case, the fixed valve pin 110 maintains the state protruding into the cavity 400, thereby helping the molten resin to be uniformly injected into the cavity 400.

When the injection of the molten resin is completed, as shown in FIG. 8, the moving valve pin 120 moves downward by the operation of the valve pin driving unit 100 to block the gate of the cavity 400.

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: clamping plate 2: spacer plate
3: holding plate 4: cavity plate
5 manifold block 6 locating ring
11: Cavity 12: Valve Pin Hole
13: runner part 20: nozzle
21: passage 30: valve pin drive unit
31 cylinder 32 piston
33: valve pin 34: heater
35: lower air passage 36: upper air passage
100: valve pin drive unit 110: fixed valve pin
111: fixed valve pin upper end 112: fixed valve pin lower end
120: moving valve pin 121: the upper portion of the moving valve pin
122: lower portion of the moving valve pin 123: fixed valve pin hole
130: piston 140: cylinder
151: lower air passage 152: upper air passage
160: manifold block 200: nozzle
210: nozzle body 211: protrusion
212: valve pin passage 213: resin passage
214: lock pin groove 215: coupling pin hole
216: rim surface 217: rounding protrusion
220: nozzle head 221: depression
222: valve pin hole 223: rounding part
224: lock pin groove 225: coupling pin hole
226: rim surface 231: lock pin
232: coupling pin 300: nozzle
310: passage 400: cavity

Claims (7)

A double valve pin nozzle apparatus for a hot runner system of an injection molding die, the double valve pin nozzle apparatus comprising:
An upper end is fixed to the fixed side mold, the lower end fixed valve pin protruding in the cavity in which the product is molded;
A moving valve pin having a longitudinal hole in which the fixed valve pin is inserted therein, the movable valve pin being mounted to be movable up and down along the fixed valve pin;
A valve pin driving unit for moving the moving valve pin up and down; And
A valve pin passage through which the fixed valve pin and the moving valve pin are inserted, and a resin passage through which a molten resin is supplied into the cavity;
Double valve pin nozzle device characterized in that the gate in which the molten resin is injected into the cavity through the resin passage of the nozzle is opened or closed by the moving valve pin.
The method of claim 1,
Double valve pin nozzle apparatus, characterized in that at least one resin passage of the nozzle is formed separately from the valve pin passage.
The method of claim 2,
The nozzle comprises a nozzle body; And a nozzle head assembled to a lower end of the nozzle body, wherein the valve valve passage is formed in a lengthwise direction of the nozzle body so that the moving valve pin can move up and down, and the valve body is formed in the nozzle body. At least one resin passage through which the molten resin can flow is formed in the longitudinal direction of the nozzle body, and the lower portion of the nozzle head is concentric with the valve pin passage so that the movable valve pin can be opened or blocked. A valve pin hole penetrated concentrically is formed, wherein the valve pin passage, the at least one resin passage, and the valve pin hole are passed through each other.
The method of claim 1,
The resin passage of the nozzle and the valve pin passage are formed in common, and the fixed valve pin and the moving valve pin are placed in the resin passage of the nozzle, and the resin passage inner diameter of the nozzle is larger than the outer diameter of the moving valve pin. And a molten resin injected into the cavity through an inner wall of the resin passage of the nozzle and an outer wall of the moving valve pin.
The method of claim 1,
The valve pin drive unit is a double valve pin nozzle device, characterized in that for operating by compressed air.
The method of claim 1,
The valve pin drive unit is a double valve pin nozzle device characterized in that the operation by the electromagnet. The method of claim 1,
The valve pin drive unit is a double valve pin nozzle device characterized in that operated by hydraulic pressure.

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