JP2010194845A - Method for manufacturing injection-molded product, and injection molding apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an injection-molded product and an injection molding apparatus capable of efficiently cooling components (a core, an insert, or the like) in a die to quicken cooling of an injection molding die and to shorten a molding cycle. <P>SOLUTION: The method for manufacturing the injection-molded product including a cylindrical first insert 3 with a first vent hole formed at one end, and a second insert 2 having a second vent hole formed to communicate with the first vent hole, comprises a first process for allowing the first vent hole and the second vent hole to communicate with each other and performing mold clamping; a second process for filling molten resin; a third process for blowing air to the first vent hole and the second vent hole to cool the inner surface part of the first insert 3; a fourth process for stopping the air; a fifth process for releasing connection between the first vent hole and the second vent hole; a sixth process for discharging a molded product; and a seventh process for cooling the outside surface of the first insert 3 with air blasted from the second vent hole for aeration. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an injection-molded product and an injection-molding apparatus that can accelerate cavity cooling of an injection mold and shorten a molding cycle.

When molding is performed in an injection mold having a core (nesting) and an outer mold, the core (nesting) is in contact with the molten resin, and therefore generally stores heat and becomes high temperature.
As described above, as a method for locally cooling a heat storage section in which a core or the like moves with an injection mold, a method of embedding a thermopipe or a method of cooling through cooling water is generally performed.

However, in the method using the thermopipe, if there is an air layer between the mold and the thermopipe, the cooling efficiency is deteriorated and the mold processing accuracy is required. Increase.
Moreover, the restriction of the shape of the part into which the thermopipe is incorporated becomes large and lacks versatility.

  Furthermore, in the method of circulating the cooling water in the slide core, there is interference with the angular pin and space restrictions, and the method of passing the cooling water in one direction (passing from the sliding core moving nest to other mold parts) Method) requires countermeasures against leakage when the moving insert is separated from the delivery mold part.

For example, a technique for cooling a core body by flowing a refrigerant from the outside of the core body in a spiral cooling groove (a cooling groove running from the upper side to the base end in the axial direction) formed on the inner wall surface of the core body is known. (For example, refer to Patent Document 1).
Patent Document 1 discloses an injection mold formed of an outer mold and a core.
The core is composed of a core main body portion in which a spiral cooling groove is formed on the inner wall surface, and a cooling bush inserted so that a gap is formed in the inner portion of the core main body portion.
A cooling medium supply path is formed in the cooling bush in the central axis direction. The cooling medium is introduced from the base end (from the outside of the mold), and the other end is the back of the core body. It communicates with the gap formed in the part.
This gap communicates with the spiral cooling groove formed in the core body, and therefore, the cooling medium introduced from the outside of the mold passes through the gap from the supply path, runs down the spiral cooling groove, It flows out of the mold from the base end.
The core is cooled by the flow of the cooling medium.

JP 09-262870 A

However, according to the technique described in Patent Document 1, since the refrigerant does not contact the outer side surface of the core, cooling is performed only from the inner wall surface side of the core body constituting the cavity. There was a problem that it took a long time.
That is, a more efficient cooling technique has been desired in order to increase the efficiency of the molding cycle.

  The object of the present invention is to solve the above-mentioned problems, efficiently cooling the component parts (core, insert, etc.) in the mold, speeding up the cooling of the injection mold and shortening the molding cycle. The present invention relates to a method for manufacturing an injection molded product and an injection molding apparatus.

  According to the method of manufacturing an injection-molded product according to the present invention, the above-described problem is a cylindrical first insert (movable entry) that is configured to be movable inside the mold body and has a first vent hole at one end. And a second insert (insertion insert) having a second vent hole formed so as to be able to communicate with the first vent hole, an inner wall of the mold body, and the first insert ( In the method of manufacturing an injection molded product, the molten resin is solidified in a cavity surrounded by the outer surface of the movable insert) and the outer surface of the second insert (insertion insert). A first step of moving a first insert (moving insert) to connect the first vent hole and the second vent hole to perform mold clamping; and a first step of filling the cavity with a molten resin Step 2 and air is blown to the first vent hole and the second vent hole to cool the inner surface portion of the first insert (moving insert). A third step of performing the first cooling, a fourth step of stopping air, and the first vent hole and the first vent hole by relatively separating the positions of the first and second inserts. A fifth step of releasing the connection with the second vent hole, a sixth step of discharging the molded product from the cavity, and blowing air from the second vent hole; This is solved by performing the second step of performing the second cooling for cooling the outer surface of the first insert by the air that has been exhausted inside the mold body.

  Further, the above-described problem is an injection molding apparatus for molding a molded product by solidifying a molten resin poured into a cavity formed inside a mold body according to the injection molding apparatus according to the present invention. The molding device is configured to be movable inside the mold body, and is configured to be able to communicate with a cylindrical first insert (movable insert) in which a first vent hole is formed at one end and the first vent hole. A second insert (insertion insert) having a formed second ventilation hole, and in a mold-clamping state, the inner wall of the mold body and the first insert ( Molten resin is injected into the cavity surrounded by the outer surface of the movable nest and the outer surface of the second nest (inserted nest), and the first vent hole and the second vent hole Are communicated, and air is blown into the first vent hole and the second vent hole, and the first insert (moving insert) In the mold open state, the first and second inserts are relatively separated from each other so that the first vent hole and the second passage are in the mold open state. When the connection with the air holes is released and air is blown into the second air holes, the air is expelled from the second air holes into the mold body, and the outer surface of the first insert is This is solved by being configured to be cooled.

Thus, in the present invention, the first nest (moving nest) is moved, the first vent hole and the second vent hole are communicated to perform mold clamping, and the first nest (moving nest) ) And the outer surface of the second insert (insertion insert) are filled with a molten resin and solidified to produce a molded product.
At this time, first cooling is performed in which air is blown to the first vent hole and the second vent hole to cool the inner surface portion of the first insert (moving insert).
For this reason, molten resin can be solidified efficiently.
Further, in the present invention, in the mold open state, the positions of the first insert and the second insert are relatively separated, and the connection between the first vent hole and the second vent hole is released to form the mold. The product is discharged from the cavity.
At this time, second cooling is performed in which air is blown from the second vent hole, the air is blown into the mold body, and the outer surface of the first insert is cooled.
For this reason, cooling of a cavity and cooling of a 1st nest can be performed efficiently.
As described above, the cooling of the injection mold can be accelerated and the molding cycle can be shortened.

Further, in the first aspect of the present invention, a third nest (embedded nest) for guiding a course of air to the inner wall surface side of the first nest is stored in the first nest. Has been
In the third step, it is preferable that air is configured to pass between the inner wall surface of the first insert and the third insert outer surface.

  Furthermore, in the invention according to claim 4, a third nest (embedded nest) for guiding a course of air to the inner wall surface side of the first nest is stored in the first nest. The air is preferably configured to pass between the inner wall surface of the first insert and the outer surface of the third insert.

If comprised in this way, the inner wall surface of a 1st insert can be cooled efficiently.
That is, since the cavity is formed in contact with the outer surface of the first insert, the cavity is formed in the cavity by cooling the inner wall surface portion of the first insert (that is, the portion that is thermally conductive with the outer surface). The adjacent part is cooled.
For this reason, the molten resin with which the cavity was filled can be solidified efficiently.

  In the invention according to claim 2, a spiral groove is formed on the inner wall surface of the first insert or the outer surface of the third insert. In the third step, the air Is preferably configured to pass through the spiral groove.

  Furthermore, in the invention according to claim 5, a spiral groove is formed on the inner wall surface of the first insert or the outer surface of the third insert, and the air is formed in the spiral groove. It is preferable to be configured to pass through.

With such a configuration, the passage resistance of the air passage is reduced, the passage of air is facilitated, and the cooling area can be increased.
In addition, this helical channel | path may be formed in the inner wall face of a 1st nest | insert, and may be formed in the outer surface of a 3rd nest | insert.

According to the present invention, the first nest (moving nest) is moved, the first vent hole and the second vent hole are communicated to perform mold clamping, and the outside of the first nest (moving nest) is removed. A molded product is manufactured by filling and solidifying a molten resin in a cavity surrounded by the side surface and the outer surface of the second insert (insertion insert). In such a clamped state, The first cooling for cooling the inner surface portion of the first nest (moving nest) is performed by blowing air to the first and second vents communicating with each other.
For this reason, molten resin can be solidified efficiently.

Moreover, in the mold open state after the molten resin is solidified, the first and second inserts are relatively separated from each other (either the first insert or the second insert may be moved). Both of them may be moved), the first vent hole and the second vent hole are disconnected, the molded product is discharged from the cavity, and air is blown from the second vent hole to Air is blown into the main body, and second cooling is performed to cool the outer surface of the first insert.
For this reason, cooling of a cavity and cooling of a 1st nest can be performed efficiently.
As described above, according to the present invention, it is possible to shorten the molding cycle by increasing the efficiency and speed of cooling the injection mold.

It is sectional drawing of the mold opening state of the injection molding apparatus which concerns on one Embodiment of this invention. It is sectional drawing of the clamping state of the injection molding apparatus which concerns on one Embodiment of this invention. It is an A direction arrow directional view of FIG. It is explanatory drawing which shows an air flow path. It is a manufacturing-process figure of the injection molded product which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Note that the configuration described below does not limit the present invention and can be variously modified within the scope of the gist of the present invention.
The present embodiment relates to an injection molded product manufacturing method and an injection molding apparatus capable of efficiently cooling each insert (core), speeding up cooling of an injection mold, and shortening a molding cycle.

  1 to 5 show an embodiment of the present invention. FIG. 1 is a sectional view of an injection molding apparatus in a mold open state, FIG. 2 is a sectional view of an injection molding apparatus in a mold clamping state, and FIG. FIG. 4 is an explanatory view showing an air flow path, and FIG. 5 is a manufacturing process diagram of an injection molded product.

The injection molding apparatus S according to this embodiment will be described with reference to FIGS.
An injection molding apparatus S according to the present embodiment includes a mold body 1, an insertion insert 2 as a second insert, a moving insert 3 as a first insert, and an embedded insert 4 as a third insert. It is configured.

As shown in FIGS. 1 and 2, a mold main body 1 according to the present embodiment is a substantially cylindrical mold configured to be openable and closable. A child 3 is provided.
As shown in FIG. 3, the mold main body 1 is divided into a first main body 1A and a second main body 1B, and can be opened and closed.
Further, a molten resin filling passage 1a for filling the cavity K described later with resin is formed.

Moreover, as shown in FIG.1 and FIG.2, the insertion insert 2 which concerns on this embodiment is a cylindrical insert fixed to the one end side inside the metal mold | die body 1, The edge part is a metal mold | die. An air introduction hole 2a for introducing air supplied from the outside of the main body 1 is formed.
Further, the air introduction hole 2a communicates with the insertion insert side air passage 2b extending in the axial direction of the insertion insert 2.

In addition, the free end portion of the insertion-insertion-side air passage 2b (the end portion on the opposite side to the end portion on the side continuous with the air introduction hole 2a, the end portion on the movable insertion portion 3 side described later) is referred to as “insertion insertion portion”. Side air discharge hole 2c ".
Further, the air introduction hole 2a, the insertion insertion side air passage 2b, and the insertion insertion side air discharge hole 2c constitute the “second ventilation hole” described in the claims.

In addition, the moving nest 3 according to the present embodiment is a substantially cylindrical nest disposed inside the mold body 1 so as to face the insertion nest 2.
The movable insert 3 is configured to slide inside the mold body 1 in a direction in which the insert insert 2 approaches and separates from the insert insert 2.

Furthermore, the inside of the movable insert 3 is hollow, and the fitting surface 3a facing the insert 2 is inserted into the insert insert side air discharge hole 2c side (hereinafter referred to as the insert insert 2). A moving insertion side fitting hole 3b having a diameter substantially the same as the diameter of “insertion insertion side insertion portion 2d” is formed, and at the time of mold clamping, the insertion insertion side insertion portion 2d is It is comprised so that it may fit in the movement insertion side fitting hole 3b (refer FIG. 2).
Further, on the side surface in the vicinity of the base end portion spaced apart from the fitting surface 3a of the moving nest 3 by a certain distance, a moving nest side air discharge hole 3c communicating with the outside is formed.

During mold clamping, the space formed by the outer surface of the insertion insert 2, the outer surface of the movable insert 3, and the inner wall of the mold body 1 becomes a cavity K and is formed into the shape of the molded product (see FIG. 2). .
The cavity K communicates with the above-described molten resin filling passage 1a, and molding is performed by flowing the molten resin from the molten resin filling passage 1a.

Further, an embedded insert 4 is disposed in the hollow interior of the moving insert 3.
The embedded insert 4 according to the present embodiment is a member made of a high heat conductive material, and has a substantially cylindrical embedded insert body 4a and a spiral formed on the outer surface of the embedded insert body 4a in a spiral shape. It has a groove portion 4b.

The embedded insert 4 has a maximum cross-sectional diameter (the diameter of the portion where the distance between both ends is the largest) that is substantially the same as the inner diameter of the movable insert 3.
That is, the embedded insert 4 is fitted into the internal hollow portion of the movable insert 3 in a state where the outer surface of the embedded insert main body 4 a is in contact with the inner wall surface of the movable insert 3.

For this reason, in the state where the embedded insert 4 is inserted into the inner wall surface of the movable insert 3, the spiral groove 4b becomes a spiral space serving as a guide path through which air passes.
This spiral space is referred to as “moving telescopic air passage 3d”.
The moving nesting air passage 3d communicates with the moving nesting side fitting hole 3b and the moving nesting side air discharge hole 3c.
The movable entry side fitting hole 3b, the movable entry air passage 3d, and the movable entry side air discharge hole 3c constitute a “first ventilation hole” described in the claims.

  In other words, when the insertion insert side insertion portion 2d is fitted into the moving insertion side fitting hole 3b, the insertion insertion side air discharge hole 2c, the moving inner air passage 3d, and the moving insertion side air are inserted. The discharge hole 3c communicates and an air passage is formed (see FIG. 2).

In this embodiment, the spiral groove 4b is formed in the embedded nest 4, but the main point is that a spiral space is formed between the inner wall surface of the movable nest 3 and the outer surface of the embedded nest 4. What is necessary is just to be necessary, and it does not necessarily need to be formed in the embedded nest 4.
That is, the “spiral groove” may be formed on the inner wall surface of the movable telescopic member 3.
In addition, from the viewpoint of low air passage resistance and cooling surface area, the spiral groove is optimally configured, but the shape is not limited to this, and the shape is particularly limited as long as it is a passage that guides air. Not.

Next, the air passage will be described with reference to FIG.
FIG. 4A shows the air passage in the clamped state with arrows.
As described above, in the mold clamping state, air is introduced from the air introduction hole 2a, passes through the insertion insert side air passage 2b, and enters the movable entry 3 from the insertion insert side air discharge hole 2c. To do.

The air that has entered the moving nest 3 travels spirally in the moving nest air passage 3d formed in a spiral shape and is discharged from the moving nest-side air discharge hole 3c.
As described above, in the mold clamping state, air passes through the moving in-nesting air passage 3d, which is a space formed by the embedded nest 4 made of a high thermal conductivity material and the inner wall of the moving nest 3. It is configured to take away heat near the surface of the nesting 3.
Therefore, the resin filled in the cavity K can be efficiently cooled.

Moreover, FIG.4 (b) shows the air path in a mold open state with an arrow.
Thus, in the mold open state, since the fitting state between the insertion insert side fitting portion 2d and the moving insertion side fitting hole 3b is released, it is introduced from the air introduction hole 2a and inserted. The air that has passed through the child-side air passage 2b is discharged into the mold body 1 from the insertion-insertion-side air discharge hole 2c.

This air flows along the outer surface of the moving telescope 3.
Therefore, in the mold open state, air flows along the outer surface of the moving nest 3, so that the outer surface of the moving nest 3 and the cavity K can be efficiently cooled.
The air on / off timing is set by the air control circuit of the injection molding apparatus S.

FIG. 5 shows a manufacturing process diagram of an injection molded product according to the present embodiment.
First, mold clamping is performed in step 1.
At this time, the mold body 1 is hermetically sealed, and the movable insert 3 is slid toward the insert insert 2 so that the insert insert side insertion portion 2d constituting the insert insert 2 is moved to the move insert. 3 is fitted into the movable insertion side fitting hole 3b.

  Thus, the cavity K (outside of the insertion insert 2 is formed so as to match the shape of the molded product by fitting the insertion insert side insertion portion 2d and the moving insertion side fitting hole 3b. A space formed by the side surface, the outer surface of the movable nest 3 and the inner wall of the mold body 1 is formed.

Next, the molten resin is filled into the cavity K in step 2.
This is filled into the cavity K from the molten resin filling passage 1 a formed in the mold body 1.

Next, in step 3, the first cooling is performed.
In this step, cooling air is introduced from the air introduction hole 2a, and the introduced air is supplied to the insertion insert side air passage 2b, the insertion insert side air discharge hole 2c, the moving entry air passage 3d, Cooling is performed through a passage formed by the moving nesting side air discharge hole 3c.
At this time, the air introduced into the moving nest 3 passes through the moving nest air passage 3d formed in a spiral shape.
Therefore, the heat near the surface of the moving nest 3 can be taken away, and the resin filled in the cavity K in contact with the outer surface of the moving nest 3 can be efficiently cooled.

Next, after the resin in the cavity K is solidified, the supply of cooling air is stopped in Step 4 and the mold is opened in Step 5.
In this mold opening, the mold body 1 is opened, and the moving insert 3 is slid in a direction away from the insertion insert 2, so that the insertion insert side insertion portion 2d and the movement insert side fitting hole are provided. The fitting with 3b is released.
Subsequently, it solidifies in the cavity K by the process 6, and takes out a molded article.

Next, in step 7, second cooling is performed.
At this time, the fitting between the insertion insertion side insertion portion 2d and the moving insertion side fitting hole 3b is released, and the insertion insertion side air discharge hole 2c is exposed inside the mold body 1. Yes.
Therefore, the air introduced from the air introduction hole 2a and passing through the insertion insertion side air passage 2b is discharged into the mold 1 from the insertion insertion side air discharge hole 2c, and the outside surface of the moving insertion element 3 is moved to the outside. Flowing along.

For this reason, the outer surface of the movable nest 3 and the cavity K are efficiently cooled.
Thus, since the moving nest 3 and the cavity K can be cooled quickly, the molding cycle can be shortened.

In the present embodiment, the moving insert 3 is moved, but the point is that the relative distance between the insertion insert 2 and the moving insert 3 may be changed, and the mold body 1 moves. Alternatively, the insertion insert 2 may not be fixed to the mold body 1 and may move to the moving insert 3 side.
Note that names such as “insert” and “move” are names given in accordance with the functions of the nestings exemplified in the present embodiment, and do not limit the functions as these inventions.

1. Mold body, 1A, 1st body, 1B, 2nd body, 1a, molten resin filling passage,
2. Insertion insert, 2a Air introduction hole, 2b Insertion insertion side air passage,
2c ··· Insertion side air discharge hole, 2d · Insertion side insertion portion,
3 ... Moving insert, 3a ... Fitting surface, 3b ... Moving insert side fitting hole,
3c ··· Moving air outlet side air discharge hole, 3d · Air passage inside the moving child,
4... Embedded insert 4 a. Embedded insert body 4 b Spiral groove
K ... cavity,
S ... Injection molding equipment

Claims (6)

A cylindrical first insert that is configured to be movable inside the mold body and has a first vent hole formed at one end thereof, and a second vent hole that is formed to be able to communicate with the first vent hole. 2 molds, and molding a molded product by solidifying the molten resin in a cavity surrounded by the inner wall of the mold body, the outer surface of the first insert and the outer surface of the second insert In the manufacturing method of the injection molded product to
A first step of clamping the mold by moving the first nest and connecting the first vent hole and the second vent hole;
A second step of filling the cavity with a molten resin;
A third step of performing a first cooling by blowing air to the first vent hole and the second vent hole to cool the inner surface portion of the first insert;
A fourth step of stopping the air;
A fifth step of releasing the connection between the first vent hole and the second vent hole by relatively separating the positions of the first insert and the second insert;
A sixth step of discharging the molded product from the cavity;
Seventh step of performing second cooling for blowing air from the second vent hole and cooling the outer surface of the first insert by the air vented into the mold body from the second vent hole. When,
A method for producing an injection-molded product, characterized in that Inside the first nesting, there is stored a third nesting for guiding the course of air on the inner wall surface side of the first nesting,
The air is configured to pass between the inner wall surface of the first insert and the outer surface of the third insert in the third step. A method for producing an injection-molded product according to 1. A spiral groove is formed on the inner wall surface of the first insert or the outer surface of the third insert,
3. The method for manufacturing an injection-molded product according to claim 2, wherein in the third step, air is configured to pass through the spiral groove. An injection molding device for molding a molded product by solidifying a molten resin poured into a cavity formed inside a mold body,
The injection molding apparatus
A cylindrical first nest configured to be movable within the mold body and having a first vent hole at one end;
A second nest having a second vent hole formed so as to be able to communicate with the first vent hole,
In the clamped state, molten resin is injected into the cavity surrounded by the inner wall of the mold body, the outer surface of the first insert, and the outer surface of the second insert, and the first 1 vent hole and the 2nd vent hole are connected, air is sent to the 1st vent hole and the 2nd vent hole, and it is constituted so that the inner surface part of the 1st insert may be cooled. In the mold open state, the first insert and the second insert are relatively separated from each other, and the connection between the first vent and the second vent is released, and the second insert When the air is blown into the air holes, the air is expelled from the second air holes into the mold body, and the outer surface of the first insert is cooled. Injection molding equipment.   A third nest for guiding the course of air is stored inside the first nest on the inner wall surface side of the first nest, and the air is connected to the inner wall of the first nest. The injection molding apparatus according to claim 4, wherein the injection molding apparatus is configured to pass between the third nested outer surface.   A spiral groove is formed on the inner wall surface of the first insert or the outer surface of the third insert, and the air is configured to pass through the spiral groove. The injection molding apparatus according to claim 5, wherein

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