JP2004050557A - Injection molding mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an injection molding mold which can mold a plurality of moldings by one shot, is good in maintenance properties, controls the occurrence of a trouble with respect to production, and is capable of executing high efficiency production. <P>SOLUTION: In the injection molding mold 1, a fixed mold 2 mounted on the surface of a fixed platen 4, a movable mold 3 which forms cavities between it and the fixed mold 2 by being mold-closed in relation to the fixed mold 2, and a hot runner 19 for supplying a molten resin into the cavities are provided, and the cavities are formed independently in the opening/closing surfaces of the fixed mold 2 and the movable mold 3. In the fixed mold 2 and the movable mold 3, a plurality of partial molds 8 and 9 which form each cavity separately are installed attachably/detachably to/from the side of the opening/closing surfaces. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding die for injection molding a resin, and more particularly to an injection molding die capable of taking a plurality of molded products by one injection.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in the production of injection molded products such as thermoplastic resins, injection molding dies capable of taking a plurality of molded products by one injection have been employed in order to increase production efficiency. As such a mold, one having a configuration as shown in FIG. 7 is generally known.
[0003]
The injection mold 100 shown in FIG. 7 includes a fixed mold 101 and a movable mold 102 which are mutually moved and separated from each other. The fixed mold 101 is attached to a fixed board 103, and the movable mold 102 is mounted on a movable board (not shown). Installed. On each surface of the fixed mold 101 and the movable mold 102 on the mold opening / closing surface of the fixed mold 101 and the movable mold 102, a cavity forming mold 106 having four independently formed cavity forming portions 104 and 105 for forming a cavity described later. , 107 are provided. In this configuration, when the movable mold 102 rises and enters the mold closed state, four cavities 108 are formed between the fixed mold 101 and the movable mold 102 for independently injecting the molten resin to form an injection molded product. It is configured to be formed.
[0004]
Here, in each of the four cavity forming portions 104 independently provided on the surface of the cavity forming die 106 provided on the surface of the fixed die 101, a hot nozzle 109 is provided just above a substantially central portion of the upper surface thereof. Is provided. The hot nozzle 109 includes a nozzle body 110 formed in a cylindrical shape, a heater 111 provided below the nozzle body 110, and a supply passage 112 provided in the nozzle body 110 to extend in the axial direction. Have. The supply passage 112 is opened at the upper end surface and the lower end surface of the hot nozzle 109, respectively, and the opening at the lower end surface is configured to communicate with a gate 113 provided to be opened on the upper surface of the cavity forming portion 104. I have.
[0005]
Here, the fixed platen 103 and the fixed die 101 are fastened by fastening means (not shown), and the upper end surface of the hot nozzle 109 is in contact with the lower end surface of the fixed platen 103. The opening of the supply passage 110 at the upper end surface of the hot nozzle 109 is configured to communicate with a branch supply passage 114 provided inside the fixed platen 103. As shown in FIG. 8, the branch supply passage 114 is provided for each cavity 108 and communicates with a main supply passage 115 extending upward inside the fixed platen 103. .
[0006]
In this configuration, since the molten resin is introduced into the cavity 108 through the long path of the main supply path 115, the branch supply path 114, and the supply path 110 of the hot nozzle 109, the heaters 111 and 116 are arranged at necessary positions in the path. , A hot runner 117.
[0007]
[Problems to be solved by the invention]
By the way, according to the conventional injection mold, four cavity forming portions 104 and 105 are formed independently on the surface of each cavity forming die 106 and 107, respectively. That is, since a plurality of cavity forming portions 104 and 105 are formed in the same cavity forming molds 106 and 107, any one of these cavity forming portions 104 and 105 may be damaged during production operation. When a problem occurs, it is necessary to replace and mount the entire cavity forming dies 106 and 107 even if it is one of the cavity forming portions 104 and 105. For this reason, there is a problem that the replacement efficiency is increased and the operation becomes inoperable during this time, resulting in poor production efficiency.
[0008]
In the same situation as above, if it is desired to give priority to production over replacement of the cavity forming dies 106 and 107, resin is similarly supplied into the defective cavity 108 to produce defective molding. It is necessary to take measures such as continuing the production, or stopping the heater 111 of the hot nozzle 109 connected to the cavity 108, and curing the resin in the hot nozzle 109 to produce the resin.
[0009]
In the former case, there is a problem that the resin material is wasted wastefully and the production cost is increased in order to continuously produce defective moldings. Further, there is a problem that the production efficiency is poor because it is necessary to remove the defective product from the molded product. In the latter case, the resin existing in the portion from the main supply passage 115 to the supply passage to the defective cavity 108 is constantly heated and seizure occurs, and the burnt resin flows back to the normal cavity side. In some cases, causing a problem in manufacturing.
[0010]
The present invention has been made in view of such circumstances, and in an injection molding die for molding a plurality of injection molded products by one injection, maintenance performance is good and there is a problem in manufacturing. It is an object of the present invention to provide an injection mold capable of suppressing the occurrence and enabling highly efficient production.
[0011]
[Means for Solving the Problems]
In order to solve the above problems and achieve such an object, the present invention proposes the following means.
The injection molding die of the present invention is a movable die which is provided on the surface of a fixed platen and which is provided on the surface of a movable platen and forms a cavity between the fixed die by being closed with respect to the fixed die. A mold, a hot runner for supplying a molten resin into the cavity, an injection mold provided with a plurality of cavities independently in the opening and closing surfaces of the fixed mold and the movable mold, At least one of the fixed mold and the movable mold is provided with a plurality of partial molds for individually forming the cavities, which are detachably provided from the opening / closing surface side.
[0012]
In this injection mold, a plurality of cavities are independently provided in the open / close surfaces of the fixed mold and the movable mold, and at least one of the fixed mold and the movable mold has a plurality of cavities each of which is separately formed. The configuration has a partial mold. Therefore, when any of the plurality of cavities has a defect such as scratches, it is possible to selectively replace and attach only the partial molds constituting the cavities. In addition, since the partial mold is configured to be detachably provided from the opening / closing surface, it is possible to easily replace and attach the partial mold, and it is possible to reduce the number of maintenance steps. Become.
[0013]
Further, in the injection mold of the present invention, the hot runner is provided with an opening / closing mechanism capable of individually opening / closing a supply passage of the molten resin into each of the cavities, and an operation unit of the opening / closing mechanism is exposed to the outside. It is characterized by doing.
[0014]
This injection molding die has a configuration in which an opening and closing mechanism that can individually open and close the supply path of the molten resin into each cavity is provided. Only the supply path of the molten resin to the cavity is completely closed, and only the supply of the molten resin into the cavity can be selectively stopped. In this case, even during the repair of the defective cavity, the production can be continued in the other cavities similarly without wasting the resin. In addition, the resin existing in the portion reaching the supply passage to the defect-producing cavity is constantly heated and seizure occurs. However, the burnt resin does not flow backward to the normal cavity side. This makes it possible to provide an injection mold that has good maintainability and that can achieve high-efficiency production without producing a manufacturing defect even if the above-mentioned problem occurs.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of an injection mold according to the present invention will be described with reference to FIGS.
The injection mold 1 shown in FIG. 1 includes a fixed mold 2 and a movable mold 3 which are brought into contact with and separated from each other. The fixed mold 2 is attached to a fixed board 4 and the movable mold 3 is attached to a movable board (not shown). Installed. When the movable mold 3 rises to the mold closed state, cavities 30 to 33 for injecting a molten resin to form an injection molded product between the fixed mold 2 and the movable mold 3, as shown in FIG. The configuration is such that four are formed independently.
[0016]
Here, four recesses are provided on the surface of the fixed mold 2 (hereinafter referred to as the surface) of the mold opening and closing surfaces of the fixed mold 2 and the movable mold 3, and each of the recesses has a cavity forming mold (partial mold) 8. Are provided respectively. In this configuration, on the surface of each cavity forming die 8, a cavity forming portion 6 for forming the cavities 30 to 33 described above is provided so as to open to the surface.
[0017]
Similarly, a concave portion is provided on the surface of the movable die 3 (hereinafter referred to as a surface) in the mold opening / closing surface, and a cavity forming die (partial die) 9 is provided in each concave portion. . In this configuration, four cavity forming portions are provided on the surface of the cavity forming die 9 corresponding to the arrangement positions of the cavity forming portions 6 provided in the fixed mold 2 with respect to the direction along the mold opening / closing surface. 7 is provided so as to be convex with respect to the surface.
[0018]
In the above configuration, as shown in FIG. 1, two cavity forming dies 8 and 9 are provided in parallel, and one each is provided in series with each other. That is, when the mold is in the closed state, the four cavities 30 to 33 are formed independently in the arrangement as shown in FIG.
[0019]
In each of the surfaces of the cavity forming dies 8, 9, a through hole and a counterbore hole having a diameter larger than that of the through hole and formed coaxially are formed outside the cavity forming portions 6, 7. A bolt 10 is inserted into the portion and screwed into a female screw provided in the fixed mold 2 and the movable mold 3 to hold the cavity forming molds 8 and 9 in the fixed mold 2 and the movable mold 3. ing.
[0020]
Here, hot nozzles 11 are provided just above substantially the center of the upper surface of the cavity forming portion 6 provided on the surface of each cavity forming die 8. The hot nozzle 11 includes a nozzle body 12 formed in a cylindrical shape, a heater 13 provided below the nozzle body 12, and a supply passage 14 provided in the nozzle body 12 to extend in the axial direction. ing. The supply passage 14 opens at the upper end surface and the lower end surface of the hot nozzle 11, and the opening at the lower end surface communicates with a gate 15 that is opened on the upper surface of each cavity forming portion 6. ing.
[0021]
Here, the fixed platen 4 and the fixed mold 2 are fastened by fastening means (not shown), and the upper end surface of the hot nozzle 11 is in contact with the lower end surface of the fixed platen 4. The opening of the supply passage 14 at the upper end surface of the hot nozzle 11 is configured to communicate with a branch supply passage 16 provided inside the fixed platen 4. As shown in FIG. 3, the branch supply passages 16 are provided for each of the cavities 30 to 33. These branch supply passages 16 are connected to the fixed platen 4 through the sub supply passages 25 as shown in FIG. It is configured such that it communicates with a main supply passage 17 extending upward and provided inside.
[0022]
In this configuration, in order to guide the molten resin into the cavities 30 to 33 through a long path of the main supply passage 17, the branch supply passage 16, the sub supply passage 25, and the supply passage 14 of the hot nozzle 11, the heater 13 is provided at a necessary portion of the passage. The hot runner 19 is formed by disposing 18.
[0023]
Here, on the front surface of the fixed mold 2, a through hole and a coaxial hole having a diameter larger than that of the through hole are provided at central portions between the cavity forming dies 8 provided in parallel shown in FIG. Counterbore holes are provided. Further, a hole which is coaxial with the through hole provided in the fixed die 2 and has substantially the same diameter is provided on a surface of the fixed platen 4 facing the fixed die 2. Opening / closing pins 20 are fitted into the holes provided in the fixed mold 2 and the fixed platen 4 respectively. Each of the opening / closing pins 20 includes a flange portion 21 that comes into contact with a bottom portion of the counterbore hole, and a main body portion 22 that has a smaller diameter than the flange portion 21 and is inserted into the through hole.
[0024]
As shown in FIG. 2, a hexagonal hole (operation portion) 23 provided around the axis of the opening / closing pin 20 on the surface of the flange portion 21 and four through holes provided approximately every 90 ° around the axis. It has a hole and a counterbore hole having a diameter larger than that of the through hole and provided coaxially. A bolt 24 is fitted into each of the through hole and the counterbore hole, and the bolt 24 is screwed into a female screw provided inside the fixed mold 2, and the opening / closing pin 20 is held by the movable mold 2. Has become.
[0025]
In this configuration, the upper end of the main body 22 of the opening / closing pin 20 has a configuration in which a branch supply passage 16 provided inside the fixed platen 4 is divided as shown in FIG. A hole having a cross section substantially the same as the cross section of the branch supply passage 16 is formed so as to communicate with each other. As shown in FIG. 3, the holes are open in a direction perpendicular to the outer peripheral surface of the main body 22, and have a configuration in which branch holes 26 to 28 branching in three directions communicate with each other. The branch holes 26 to 28 are provided in the outer peripheral surface of the main body 22 at intervals of 90 ° with respect to the axial direction of the opening / closing pin 20. In the case shown in FIG. 3, all the branch holes 26 to 28 are configured to communicate with the branch supply passage 16 or the sub supply passage 25.
[0026]
A method for forming an injection-molded article by using the thus-configured injection mold 1 will be described. The movable mold 3 is raised with respect to the fixed mold 2, and molten resin injected from one injection cylinder (not shown) is hot-filled in four cavities 30 to 33 formed on the mold opening and closing surfaces of the two molds 2 and 3. By filling the resin from each supply passage 16 while branching through the runner 19 and pressing the filled resin, four injection molded products are formed at the same time.
[0027]
Next, a description will be given of a countermeasure in a case where a defect such as a scratch is generated in the cavity forming portions 6 and 7 while the injection molding die 1 is in operation.
First, a case where a problem occurs in the cavity forming portions 6 and 7 forming the cavity 32 shown in FIG. 4 will be described. In order to stop the supply of the molten resin into the cavity 32, in FIG. 2, the bolt 24 provided on the flange portion 21 of the opening / closing pin 20 is removed, and a hexagon wrench or the like is fitted into the hexagon hole 23, as shown in FIG. Then, the opening / closing pin 20 is rotated counterclockwise by about 90 ° with respect to the axis of the opening / closing pin 20, and the opening / closing pin 20 is similarly rotated.
[0028]
Thereby, the branch hole 26 is communicated with the sub-supply passage 25, the branch hole 27 is communicated with the branch supply passage 16 communicating with the cavity 31, and the branch supply passage 16 communicating with the cavity 32 is The main body 22 is blocked by the outer peripheral surface. Here, since four through holes and counterbore holes provided in the flange portion 21 of the opening / closing pin 20 are provided about every 90 ° around the axis of the main body portion 22, the rotation is performed. Also, the opening / closing pin 20 can be held on the fixed mold 2 by the bolt 24 as before the rotation.
[0029]
Next, the cavity forming dies 8 and 9 having the cavity forming portions 6 and 7 in which the above-mentioned problem has occurred are removed from the fixed mold 2 and the movable mold 3 by removing the bolts 10. As described above, the supply of the molten resin to the defective cavity 32 is stopped, and the production is continued in the same manner by the remaining cavities 30, 31, and 33 with the cavity forming dies 8, 9 forming the cavity 32 being removed. It becomes possible to do.
[0030]
Next, a case where a problem occurs in the cavity forming portions 6 and 7 that form the cavities 31 and 32 will be described with reference to FIG. In this case, the opening / closing pin 20 is further rotated about its axis by about 90 ° from the state shown in FIG. As a result, the branch supply passage 16 communicating with each of the cavities 31 and 32 does not communicate with the sub supply passage 25. That is, the sub supply passage 25 is blocked by the outer peripheral surface of the main body 22 of the opening / closing pin 20, and the supply of the molten resin into the cavities 31 and 32 is stopped. Thereafter, in the same manner as described above, the cavity forming dies 8, 9 for forming the cavities 31, 32 are removed, and in this state, the production can be continued with the remaining cavities 30, 33 in the same manner.
[0031]
Next, a case where a problem occurs in the cavity forming portions 6 and 7 forming the cavity 31 will be described with reference to FIG. In this case, the opening / closing pin 20 is further rotated about its axis by about 90 ° from the state shown in FIG. Thereby, the branch hole 28 communicates with the sub supply passage 25, the branch hole 27 communicates with the branch supply passage 16 communicating with the cavity 32, and the branch supply passage 16 communicating with the cavity 31 is As a result, the supply of the molten resin into the cavity 31 is stopped. Thereafter, by performing the same operations as described above, it is possible to continue production with the remaining cavities 30, 32, and 33 in a state where the cavity forming dies 8, 9 that form the cavities 31 are removed.
[0032]
As described above, according to the injection molding die according to the present embodiment, the plurality of cavities 30 to 33 are independently provided in the open / close surfaces of the fixed mold 2 and the movable mold 3, and the fixed mold 2 and the movable mold 3 are movable. The mold 3 has a configuration in which a plurality of cavity forming dies 8 and 9 for separately forming the cavities 30 to 33 are provided. Therefore, when any of the cavities 30 to 33 has a defect such as a flaw, it is possible to selectively replace only the cavity forming dies 8 and 9 constituting the cavities 30 to 33. Become. Further, since the cavity forming dies 8 and 9 are provided so as to be detachable from the opening / closing surface, the dies 8 and 9 can be easily replaced and mounted, and the number of maintenance steps can be reduced. Can be achieved.
[0033]
Further, since the opening / closing pins 20 are provided for individually opening and closing the branch supply passages 16 for supplying the molten resin to the cavities 30 to 33, when a failure occurs in any of the cavities 30 to 33, Only the branch supply passage 16 communicating with the cavity can be fully closed, and the supply of the molten resin into the cavity can be selectively stopped. In this case, even during the repair of the defective cavity, the production can be continued in the other cavities similarly without wasting the resin. Further, the resin existing in the branch supply passage 16 leading to the supply passage 14 to the above-mentioned defective cavity is always heated and seizure occurs. However, the burnt resin does not flow back into the normal cavity. As described above, it is possible to provide an injection mold having good maintainability and capable of realizing high-efficiency production without causing a manufacturing defect even if the above-mentioned problem occurs.
[0034]
The technical scope of the present invention is not limited to the above-described embodiment, and various changes can be made without departing from the spirit of the present invention. For example, in the present embodiment, a configuration in which four cavities 30 to 33 are provided has been described. However, the configuration is not limited to four and may be a configuration having two or more cavities.
[0035]
【The invention's effect】
As is apparent from the above description, according to the injection molding die of the present invention, when any of the cavities provided has a defect such as scratches, the partial mold constituting the cavity Only the replacement can be selectively installed. In addition, since the partial mold is configured to be detachably provided from the opening / closing surface, it is possible to easily replace and attach the partial mold, and it is possible to reduce the number of maintenance steps. Become. Further, since an opening / closing mechanism that can individually open and close the supply passage communicating with each cavity is provided, even if the above-described problem occurs, the production can be performed without causing a manufacturing problem by another normal cavity. It is possible to continue.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an injection mold according to an embodiment of the present invention.
FIG. 2 is a view taken along line X1-X1 in FIG.
FIG. 3 is a sectional view taken along line X2-X2 of FIG.
4 is a cross-sectional view taken along the line X2-X2 of FIG. 1 showing a state where the opening / closing pin (main body 22) in FIG. 3 is rotated counterclockwise by about 90 ° from a position around the axis.
5 is a cross-sectional view taken along the line X2-X2 of FIG. 1 and showing a state where the opening / closing pin (main body 22) in FIG. 4 is rotated counterclockwise by about 90 ° from a position around the axis.
6 is a cross-sectional view taken along the line X2-X2 of FIG. 1, showing a state where the opening / closing pin (the main body 22) in FIG. 5 is rotated counterclockwise by about 90 ° from a position around the axis.
FIG. 7 is a cross-sectional view showing an injection mold in a conventional example according to the present invention.
FIG. 8 is a sectional view taken along line YY of FIG. 7;
[Explanation of symbols]
Reference Signs List 1 injection molding die 2 fixed die 3 movable die 4 fixed plate 8, 9 cavity forming die (partial die)
16 branch supply passage 17 main supply passage 19 hot runner 20 opening / closing pin (opening / closing mechanism)
25 auxiliary supply passage 23 hexagonal hole (operation part)
30-33 cavity

Claims (2)

A fixed die provided on the surface of the fixed platen, a movable die provided on the surface of the movable platen and closed with the fixed die to form a cavity between the fixed die, and a molten resin in the cavity. And a hot runner for supplying an injection mold, wherein the plurality of cavities are independently provided in a plurality of opening and closing surfaces of the fixed mold and the movable mold,
Injection molding dies, characterized in that at least one of the fixed mold and the movable mold is provided with a plurality of partial molds for individually forming the cavities, which are detachably provided from the opening / closing surface side. The injection mold according to claim 1,
The hot runner is provided with an opening and closing mechanism capable of individually opening and closing a supply path of the molten resin into each of the cavities, and an operation unit of the opening and closing mechanism is exposed to the outside. Type.

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