JP2002079548A - Injection molding die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a runner lock member to be introduced into and removed from the interior of a die and a runner to be removed to the outside of the mold using the runner lock member. SOLUTION: In the injection molding die with a cavity, the runner is locked by means of the member which can be introduced into and removed from the die.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding die, and more particularly to an injection molding die having a runner lock mechanism in an injection molding die so that a runner can be taken out of the die. Things.

[0002]

2. Description of the Related Art In a conventional injection molding die, a method commonly used as a locking method for a sprue runner (hereinafter simply referred to as a runner) is, for example, as shown in FIG. Some use.

[0003] Such a conventional injection mold 100 is used.
Is a fixed side mounting plate 101 provided with a sprue bush 112 and a locating ring 114 for mounting the mold 100 on a molding machine (not shown), a stripper plate 102, and a cavity in which a molded product S of molten resin is formed. A fixed side mold plate 103 provided with a sprue runner 113 for injecting into the mold 111; a movable side mold plate 104 provided with a cavity 111 for a molded product S;
The movable side receiving plate 105 for receiving nests and the like placed in the fixed side template 103 and the upper and lower ejector plates 108 and 109 increase the rigidity of the ejector pins 1 and 2.
A spacer block 106 for forming a space for projecting the mold 10, a movable-side mounting plate 107 for mounting the mold 100 on a molding machine, an upper ejector plate 108 and a lower ejector plate 109 for holding an ejector pin 110, and a mold opening. And an ejector pin 110 for projecting the molded product S from the mold 100 later.

As shown, locate ring 114
Is mounted on the fixed side mounting plate 101, and the molding machine and the mold 1
A sprue bush 112 on which a primary sprue 113a is formed for positioning of the nozzle and a nozzle touch surface which is in contact with the molding machine nozzle and which is a passage of the molten resin.
Is provided. The fixed-side mold plate 103 is formed with a sprue runner 113 and a secondary sprue 113b.
A part of the shape of the molded product S is processed.

FIG. 8 shows a state in which the molten resin is injected into the cavity 111 in which the molded product S is formed via the sprue bush 112 and the sprue runner 113 with the mold 100 closed. In this case, the tip of the runner lock pin 115 is processed into an undercut shape, and the molten resin is cooled and solidified so as to surround the undercut shape portion.

This mold system is called a three-plate system, and a gate system is a pinpoint gate.

FIG. 9 is a view showing a state in which the conventional mold shown in FIG. 8 is opened and the runner lock is released. Mold 1
As the opening order of 00, the opening between the stripper plate 102 and the fixed-side mold plate 103 is opened by the opening force of the spring 121. At this time, the sprue runner 113 is fixed to the stripper plate 102 to be held by the runner lock pin 115, and the gate is cut. When the mold is further opened, the space between the stripper plate 102 and the fixed-side mounting plate 101 is opened by the puller bolt 120 incorporated into the fixed-side mold plate 103, and the opening amount is regulated by the stop bolt 119. Since the runner lock pin 115 is fixed to the fixed-side mounting plate 101, the runner lock pin 115 is forcibly extracted from the sprue runner 113 by the movement of the stripper plate 102.

As a result, the runner lock is released, and the sprue runner 113 is taken out of the mold 100 by a runner take-out machine or an ejector pin 110 incorporated in the mold.

[0009]

As described above, in the conventional mold, the runner lock pin 115 and the stripper plate 10 are used to lock the sprue runner 113.
2. Since the mold parts such as the puller bolt 120 and the stop bolt 119 are required, the mold structure is complicated as a whole. Further, the length of the sprue runner 113 forming the primary sprue 113a is increased by the thickness of the stripper plate 102, which requires more resin material. Further, in order to forcibly remove the undercut-shaped portion of the runner lock pin 115 from the sprue runner 113, there is generation of a shaved resin residue. It is one.

In some cases, the runner lock pins 115 obstruct the flow of the resin. That is, in order to take out the sprue runner 113 out of the mold 100 after the mold 100 is opened and the runner lock is released, the ejector pins 11 incorporated in the mold 100 are required.
There is a method of popping out the sprue runner-113 by 0 or the like. In this method, the sprue runner 11
3 jumps into the fixed side template 103 or puller bolt 1
It is often observed that the mold 100 is crushed by being caught by the support pins 20, the support pins, or the like and closing the mold 100, thereby interrupting the molding. Also, the sprue runner 11
Although there is a method of removing 3 with a runner take-out machine, an expensive runner take-out machine is required. Further, since the runner take-out machine operates after the mold 100 is opened, a molding cycle may be lengthened. .

Accordingly, an object of the present invention is to solve the above-mentioned problems by enabling the runner lock member to enter and exit the mold, and by using the runner lock member to move the sprue runner out of the mold. An object of the present invention is to provide a mold for injection molding that can be removed.

[0012]

In order to achieve the above-mentioned object, the present invention provides an injection molding die having a cavity, wherein the runner lock is provided by a member which can enter and exit the die. Is performed.

Further, the injection molding die of the present invention is characterized in that the runner is held by the runner lock member and can be taken out of the die.

Further, the injection molding die of the present invention is characterized in that the runner lock member and the runner are separated by the movement of the runner take-out member from the die to the outside of the die.

Further, the injection molding die of the present invention comprises:
It has a runner lock member formed with a runner lock mechanism using a runner withdrawal taper shape.

The injection molding die of the present invention is characterized in that it has a mechanism for positioning the runner lock member in the die and holding it so as not to move by the injection pressure.

Further, the injection mold of the present invention is characterized in that the runner lock mechanism has means for moving in the mold opening direction in order to extract the primary sprue.

Furthermore, the injection molding die of the present invention is characterized in that it has a means for pressing the runner lock member against the fixed side mounting plate when the gate is cut by opening the die.

Furthermore, the injection molding die of the present invention is characterized in that the runner has a trapezoidal cross-sectional shape having a tapered portion.

According to the injection molding die of the present invention, the runner lock member as a member which can be moved in and out of the die is processed into a fixed side mold plate by processing a part of the runner shape. One runner is used depending on the shape. At this time, the secondary sprue comes to a runner position formed on a runner lock member which is a member that can enter and exit. The runner has a trapezoidal shape having a tapered portion. A mechanism is provided for positioning the runner lock member at an appropriate position in the mold and preventing the runner lock member from being moved by the injection molding pressure.

Further, a mechanism for pressing the runner lock member against the fixed side mounting plate at the time of opening the mold may be provided. The runner lock member is connected to a moving means such as an air cylinder outside the mold, and one of them is for entering and exiting the mold, and the runner lock member can be moved in the mold opening direction as necessary. Connect with means.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION In the injection molding die of the present invention, when the runner lock member is formed into a runner shape, two
By positioning the next sprue portion, a force applied at the time of gate cutting is received, and a secondary sprue portion is subjected to a force for releasing from the mold, thereby performing the same function as the runner lock pin. At this time,
The runner can be held by the runner lock member by utilizing the tapered shape of the runner having a trapezoidal cross section.
In addition, a positioning pin is provided as a guide pin for positioning the runner lock member at an appropriate position in the mold to prevent interference between the fixed mold plate and the runner lock member, and at the same time, the runner lock is provided by injection molding pressure. It is necessary to prevent the resin from leaking from the part where the lock member and the fixed-side template are joined together.

At this time, a member incorporating a spring is disposed on the fixed side mold plate, and when the mold starts to open, the runner lock member is pressed against the fixed side mounting plate to cut the gate and release the runner. It is also possible to prevent the lock member from bending or the like.

In the case of a runner having a primary sprue, it is necessary to move the runner lock member in the mold opening direction to completely pull out the primary sprue from the sprue bush. There is also a need for a mechanism that can be moved. The runner lock member is pulled out of the mold by a connected air cylinder or the like, and at that time, as a method of removing the runner from the runner lock member, a block for runner separation is provided,
A part of the runner can be forcibly separated by hitting a part of the runner to the runner separation block by using the movement of pulling the runner out of the mold.

Other objects, features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings.

(Embodiment 1) FIGS. 1 to 4 are drawings of a mold showing an embodiment 1 of an injection mold according to the present invention. FIG. 1 is a longitudinal sectional view showing the whole mold. 2 is a partially enlarged view of FIG. 1, and FIGS. 3 and 4 are views after opening the mold and discharging the sprue runner to the outside of the mold.

FIGS. 5 and 6 are enlarged views of the state of the runner lock.

As shown in FIG. 1, the injection mold 10 of the present invention comprises a fixed mold 11 and a movable mold 12, and the fixed mold 11 is fixed to a fixed mounting plate 13. The movable mold 12 includes a movable mold plate 15, a receiving plate 16, a spacer block 17, a movable mounting plate 18, upper and lower ejector plates 19 and 20, and ejector pins 21. It is schematically configured. The basic configuration of the injection mold 10 according to the present invention is substantially the same as that of the above-mentioned conventional general injection mold.

As shown, in this embodiment, the fixed side mounting plate 13 is provided with a sprue bush 26 and a locate ring 28, and the fixed side mold plate 14 is located between the fixed side mounting plate 13 and the fixed side mounting plate 13. A runner lock member 22 is provided. The runner lock member 22 includes a runner 27
The runner lock member 22 is connected to an air cylinder or the like (not shown) via a runner separation block 23, and the mold is activated by the operation of the air cylinder. It is configured to be able to enter and exit from 10,
It also serves as a runner take-out member.

As shown in FIG. 5, the runner lock member 22 is provided with a positioning hole 29 into which a positioning portion of the positioning pin 24 is fitted. The positioning pin 24 is inserted and fitted at the time of tightening. That is, as clearly shown in FIG. 2, the positioning pin 24 includes a pin portion as a positioning portion and a disk-shaped portion, and the positioning pin 24 is provided inside the stepped recess of the fixed side mold plate 14 so that the pin portion protrudes upward. It is attached so that it does not come off.

As shown, the sprue bush 26
Is injected into the mold 10 at a predetermined position,
After filling the runner-shaped portion formed on the runner lock member 22 held by the positioning pin 24,
The molded product S is injected into the cavity 30 in which the molded product S is formed through the gate 31 through the secondary sprue 27b. At this time, the positioning pin 24 has a function of holding the runner lock member 22 so as not to move outside the mold 10 due to the filling pressure, and also has a function of preventing the runner lock member 22 from bending. is there.

After the filled resin is cooled and solidified, the space between the fixed mounting plate 13 and the fixed mold plate 14 is opened (FIG. 3). At this time, the runner 27 is
2 is held by the tapered shape. The runner lock member 22 is pressed against the fixed mold plate 14 by the force of a pressing spring 25 incorporated behind the positioning pin 24. In this state, the gate 31 is cut by the mold opening operation. When the mold 10 is opened to a predetermined position, the runner lock member 22 holding the runner 27 is moved in the mold opening direction by a spring, an air cylinder, or the like, so that the primary sprue 27a portion is separated from the sprue bush 26. Remove completely outward.

Next, the moving means such as an air cylinder connected to the runner lock member 22 is operated to move the runner lock member 22 out of the mold 10. At this time, the runner separation block 2 installed outside the mold 10
The runner 27 is forcibly separated by the runner lock member 22 by applying a part of the runner 27 to the runner 27. Thus, after the runner 27 is removed, the runner lock member 22 is moved into the mold 10. When the mold 10 is closed, the positioning portion of the positioning pin 24 provided on the fixed side mold plate 14 jumps into a positioning hole 29 formed in the runner lock member 22 and is positioned and held at a predetermined position. .

(Embodiment 2) FIG. 6 is a view showing another embodiment of the injection mold of the present invention. As shown,
In this embodiment, the injection mold 10 ′ is a fixed mold 1.
A hot sprue bush 26a is used instead of the sprue bush, and a hot sprue bush spacer 13a for the hot sprue bush 26a is provided. Is different from that of the first embodiment,
Other configurations are substantially the same as those of the first embodiment. Therefore, since the primary sprue portion is eliminated by using the hot sprue bush 26a having the hot sprue flow path 32, it is not necessary to move the runner lock member 22 in the mold opening direction.

As described above, in the present invention, first, the runner lock pin, the stop bolt, the puller bolt, and the runner stripper plate can be omitted by enabling the runner lock member to be put in and taken out of the mold. . Thereby, the structure of the mold is simplified, and the cost of the mold can be reduced.

Further, since the stripper plate can be omitted, the sprue can be shortened by the thickness of the stripper plate, so that the material cost can be reduced. Furthermore, since it is not necessary to forcibly remove the runner lock pin from the runner, there is no occurrence of resin residue, and there is no problem such as crushing of a mold due to resin residue or adhesion of resin residue to a molded product. Completely gone. Also, since there is no runner lock pin, the runner lock member can be provided near the center of the mold,
Therefore, the size of the runner can be reduced.

Furthermore, the runner lock member allows the runner to be reliably ejected from the mold, thereby eliminating mold breakage due to pinching the runner between the molds and stopping the molding machine, thereby increasing the operating rate. In addition, since the runner can be discharged by a simple method without requiring an expensive take-out robot or the like, the capital investment cost can be reduced.

[0038]

According to the injection molding die according to the first aspect of the present invention, in the injection molding die having a cavity, the runner lock is performed by a member that can enter and exit the die. Lock pins, stop bolts, puller bolts, runner stripper plates, and the like can be omitted, and the die structure can be simplified, and die costs can be reduced. Furthermore, the sprue can be shortened by the thickness of the runner stripper plate,
Since the material cost can be reduced, and there is no need to forcibly remove the runner lock pin from the runner, there is no resin residue, and there is no mold crush due to resin residue or trouble due to adhesion to molded products. There is no.

In the injection molding die according to the second aspect of the present invention, the runner is held by the runner lock member and can be taken out of the die, so that the runner can be reliably held and easily discharged from the die. can do.

In the injection molding die according to the third aspect of the present invention, a special means is provided because the runner lock member and the runner are separated by the movement of the runner take-out member from the die to the outside of the die. Instead, the runner can be taken out and released from the mold by the runner lock member also serving as the runner take-out member.

The injection molding die according to the fourth aspect of the present invention has a runner lock member provided with a runner lock mechanism utilizing a runner taper shape, so that the runner can be easily removed by separating the mold. Can be.

The injection molding die according to the fifth aspect of the present invention has a mechanism for positioning the runner lock member in the die and holding it so as not to move by the injection pressure. Positioning and holding can be performed reliably, and resin leakage can be prevented.

In the injection molding die according to the sixth aspect of the present invention, the runner lock mechanism has means for moving the primary sprue in the die opening direction so that the runner can be easily removed and taken out. .

The injection molding die according to the present invention has a means for pressing the runner lock member against the fixed side mounting plate when the gate is cut by opening the die. The bending of the runner lock member can be prevented.

In the injection molding die according to the present invention, since the runner has a trapezoidal cross-sectional shape having a tapered portion, the runner can be easily separated and can be easily taken out and processed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing Example 1 of an injection mold according to the present invention.

FIG. 2 is an enlarged view of a mechanism for pressing a runner lock member toward a fixed-side mounting plate.

FIG. 3 is a view showing a state in which a gate is cut off in a state where a mold is opened and a primary sprue is pulled out from a sprue bush in Embodiment 1 of the present invention.

FIG. 4 is a view showing a state in which a runner held by a runner lock member is pulled out of a mold and separated from the runner lock member by a runner separating block.

FIG. 5 is a view showing a state in which the runner lock member locks the runner.

FIG. 6 is a sectional view taken along line AA of FIG. 5;

FIG. 7 is a cross-sectional view of an injection mold according to a second embodiment of the present invention.

FIG. 8 is a sectional view of an injection molding die showing a conventional runner lock method.

FIG. 9 is a view showing a state in which a runner lock in a mold opening operation of a conventional mold is released.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Injection mold 10 'Injection mold 11 Fixed mold 11' Fixed mold 12 Movable mold 12 'Movable mold 13 Fixed mounting plate 13a Spacer for hot sprue bush 14 Fixed mold Plate 15 Movable mold plate 16 Receiving plate 17 Spacer block 18 Movable mounting plate 19 Upper ejector plate 20 Lower ejector plate 21 Ejector pin 22 Runner lock member 23 Runner separation block 24 Runner lock member positioning pin 25 Spring 26 Sprue bush 26a Hot Sprue bush 27 Runner 27a Primary sprue 27b Secondary sprue 28 Locate ring 29 Positioning hole 30 Cavity 31 Gate 32 Hot sprue channel S Molded product

Claims (8)

[Claims] 1. An injection molding die having a cavity, wherein a runner lock is performed by a member that can enter and exit the die. 2. The injection mold according to claim 1, wherein the runner is held by a runner lock member and can be taken out of the mold. 3. The injection mold according to claim 2, wherein the runner lock member and the runner are separated by a movement of the runner take-out member from the mold to outside the mold. 4. The injection molding die according to claim 1, further comprising a runner lock member formed with a runner lock mechanism utilizing a runner taper shape. 5. The injection mold according to claim 1, further comprising a mechanism for positioning the runner lock member within the mold and holding the runner lock member so as not to move by the injection pressure. . 6. The injection mold according to claim 1, wherein the runner lock mechanism has a means for moving in a mold opening direction in order to extract the primary sprue portion. 7. When the gate is cut by opening the mold,
The injection mold according to any one of claims 1 to 6, further comprising means for pressing the runner lock member against the fixed mounting plate. 8. The injection mold according to claim 1, wherein the runner has a trapezoidal cross section having a tapered portion.