JP2016055547A - Molding die and molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding die capable of simplifying a die structure, and improving a filling property of a molding material into a molding part on condition that sectility between a molded article and a gate part is secured; and to provide a molding method.SOLUTION: A molding die includes: a first molding tool 10; and a second molding tool 20 contactable with/separable from the first molding tool 10, for defining a molding part C between itself and the first molding tool 10. The first molding tool 10 has a gate opening 14A opened on a side face part intersected with each moving direction of at least the first molding tool 10 and the second molding tool 20, in the molding part C.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a molding die used for, for example, injection molding and the like, and a molding method.

  In injection molding, etc., the first molding die and the second molding die facing each other are clamped and melted through a gate in a molding portion defined between the first molding die and the second molding die. Injected resin material. Then, after solidifying the resin material in the molding part, the first molding die and the second molding die are opened, and the molded product is taken out from the molding part to obtain a molded product corresponding to the inner shape of the molding part. be able to.

Here, as a gate system in which a resin material is injected into a molded part, a side gate is generally used in order to obtain a molded product with less deformation and warpage. The side gate extends along the die mating surface of the first molding die and the second molding die, and opens at the side surface portion of the molding portion.
Moreover, in the metal mold | die using the side gate mentioned above, the structure provided with the gate cut pin for cut | disconnecting between a molded article and a gate part (gate cut) is known (for example, refer patent document 1).

JP-A-8-309802

  However, in the configuration of Patent Document 1 described above, a gate cut mechanism such as a gate cut pin and a mechanism for operating the gate cut pin is required separately, and there is a problem that the structure of the mold is complicated.

In addition, it is also conceivable to use a pin gate as a configuration in which the gate is automatically cut between the molded product and the gate portion at the timing of mold opening after molding. The pin gate extends in a direction intersecting the die mating surface in either one of the first molding die and the second molding die, and opens in the molding portion.
However, when using a pin gate, if the cross-sectional area of the gate opening is large, when the gate is cut, the molded product will be pulled to the gate part side and the cutting performance will be reduced, causing deformation and warping of the molded product. There is a risk.
On the other hand, when the gate opening is made small, the cutting performance at the time of gate cutting is improved, but the pressure loss when the resin material is injected into the molded portion is increased, and the filling property into the molded portion is lowered. In this case, a defect such as sink marks is caused in the molded product.

  Accordingly, the present invention has been made in view of the above circumstances, and while simplifying the mold structure and ensuring the cutting property between the molded product and the gate portion, the molding material into the molding part is obtained. It is providing the shaping | molding die which can improve a filling property, and a shaping | molding method.

In order to solve the above-described problems, the molding die of the present invention can be brought into and out of contact with the first molding die, and a molding part is defined between the first molding die. A gate opening that opens at least in a side surface portion intersecting a moving direction of the first molding die and the second molding die in the molding portion. It is characterized by having.
The molding method of the present invention is a molding method using the molding die of the present invention, wherein the first molding die and the second molding die are in contact with each other. A filling step of filling a molding material into the molding part through the gate opening; and a mold opening step of separating the first molding die and the second molding die. In the mold opening step, the gate opening A shearing force is applied to a molding material located at a boundary portion between the molding part and the gate opening at a portion located on the second molding die side in the moving direction, and the molding material is cut. It is a feature.

According to this configuration, in the mold opening process between the first mold and the second mold, the boundary portion between the molded portion and the gate opening is formed by the portion located on the second mold side of the opening edge of the gate opening. A shearing force can be applied along the moving direction between the molding material and the molding material located at the position. As a result, the gate can be automatically cut at the timing of opening the connecting portion between the molded product molded in the molding portion and the gate portion molded in the gate.
In particular, unlike the conventional side gate, it is not necessary to separately provide a gate cut mechanism such as a gate cut pin, so that it is possible to ensure cutting performance while simplifying the mold structure. Therefore, deformation and warpage of the molded product can be suppressed and the product can be formed into a desired shape. In addition, according to the structure of this invention, since a shear force is made to act on the connection part of a molded product and a gate part as mentioned above, the fall of the cutting property accompanying expansion of the cross-sectional area of a gate opening is suppressed compared with a pin gate. it can.
Furthermore, by adopting a side gate in which the gate opening is opened at the side surface portion of the molded part, the pressure loss can be reduced and the resin material can be smoothly supplied along the in-plane direction of the molded part. Therefore, the filling property can be improved and the occurrence of sink marks or the like can be suppressed as compared with the case where a pin gate is employed.

Further, the molding die of the present invention protrudes in a direction intersecting the moving direction at a portion of the first molding die located on the second molding die side in the moving direction with respect to the gate opening. A support portion that defines the side surface portion may be formed.
According to this configuration, the support portion extending in the direction intersecting the moving direction is formed in the portion of the first mold that is located on the second mold side with respect to the gate opening. The gate portion is separated from the second mold together with the first mold while the gate portion is held from the second mold side by the support portion. Thereby, a shearing force can be reliably applied to the connection portion between the molded product and the gate portion, and the molded product and the gate portion can be reliably cut.

Further, in the molding die of the present invention, the gate opening is arranged across a corner portion formed by the side surface portion and an opposing portion of the first molding die facing the molding portion in the moving direction. It may be provided.
According to this configuration, the opening area of the gate opening is formed across the corner portion formed by the side surface portion of the molding portion and the opposing portion facing the inside of the molding portion in the moving direction in the first mold. Can be enlarged. Thereby, the pressure loss at the time of passing through a gate opening can be suppressed, and a filling property can be improved further.

  ADVANTAGE OF THE INVENTION According to this invention, while aiming at simplification of a metal mold | die structure and ensuring the cutting property between a molded article and a gate part, the filling property of the molding material in a molding part can be improved.

It is sectional drawing of the metal mold | die in embodiment of this invention. It is the perspective view which looked at the 1st mold from the type matching surface side. It is the perspective view which looked at the 2nd shaping die from the die matching surface side. It is the IV section enlarged view of FIG. It is a perspective view of a resin molding. It is process drawing for demonstrating a mold opening process, Comprising: It is sectional drawing equivalent to FIG. It is process drawing for demonstrating an extraction process, Comprising: It is sectional drawing equivalent to FIG. It is a figure which shows the modification of embodiment of this invention, and is an enlarged view equivalent to FIG.

Next, embodiments of the present invention will be described with reference to the drawings.
[Mold]
FIG. 1 is a cross-sectional view of the mold 1, and FIG. 2 is a perspective view of the first mold 10 viewed from the mold matching surface 11 side. FIG. 3 is a perspective view of the second mold 20 as viewed from the mold matching surface 21 side. FIG. 4 is an enlarged view of a portion IV in FIG.
As shown in FIGS. 1 to 4, the mold 1 is disposed so as to be opposed to the first mold 10 and the first mold 10, and the second mold that defines the molding portion C between the first mold 10. The molding die 20 and a drive mechanism (not shown) that relatively moves the first molding die 10 and the second molding die 20 in the Z direction (moving direction) so as to be able to contact and separate are provided. In the present embodiment, the first mold 10 is a fixed mold, and the second mold 20 is a movable mold that contacts and separates from the first mold 10 by a drive mechanism (not shown).

  As shown in FIGS. 1, 3, and 4, the second molding die 20 is recessed in the die-matching surface 21 facing the first molding die 10 on the side opposite to the first molding die 10 side in the Z direction. A cavity portion 22 is formed. The cavity 22 communicates with the molding recess 23 that molds the inner surface shape of the molded product S (see FIG. 5), and the guide recess 24 that houses the later-described projection 12 of the first mold 10. And.

FIG. 5 is a perspective view of a resin molded body.
As shown in FIG. 5, the molded product S of the present embodiment is a thin plate having a rectangular shape in plan view when viewed from the Z direction, for example. Therefore, the molding recess 23 is rectangular in plan view and has a certain depth with respect to the mold matching surface 21. The molding recess 23 is provided with an undercut portion (not shown) for preventing the molded product S from being lifted when the mold is opened.

  As shown in FIG. 3, the guide recess 24 has a rectangular shape in plan view, and from the central portion of the inner surface 23 a located on one end side in the long side direction to the molding recess 23 among the inner surfaces of the molding recess 23. It is extended outward. The depth of the guide recess 24 is equal to the depth of the molding recess 23.

  As shown in FIGS. 1, 2, and 4, the first mold 10 closes the cavity portion 22 of the second mold 20 and abuts against the mold matching surface 21 of the second mold 20 during mold clamping. A mold matching surface 11 is provided. The space defined by the first molding die 10 (mold matching surface 11) and the molding recess 23 of the second molding die 20 defines a molding part C for molding the molded product S. Yes.

  On the mold matching surface 11 side of the first mold 10, a convex portion 12 that protrudes toward the second mold 20 with respect to the mold matching surface 11 is formed. The convex portion 12 has a rectangular parallelepiped shape and is accommodated in the above-described guide concave portion 24 at the time of clamping. Therefore, of the outer surface of the convex portion 12, the outer surface 12a facing the inside of the molding recess 23 is flush with the inner side surface 23a (see FIG. 3) described above, and the side surface portion C1 of the molding portion C is formed together with the inner side surface 23a. It is composed. In addition, the front end surface 12b located in the 2nd shaping | molding die 20 side in the convex part 12 is made into the flat surface parallel to the type | mold matching surface 11, and abuts on the bottom face of the guide recessed part 24 at the time of mold clamping. Yes.

  As shown in FIG. 4, the first molding die 10 has a gate 13 extending in the Z direction for supplying a molten resin material (molding material) supplied from a supply source (not shown) into the molding part C. Has been. Specifically, the gate 13 has a tapered shape in which the inner diameter gradually decreases toward the downstream side (the mold matching surface 11 side) in the flow direction of the resin material. Further, the downstream end portion of the gate 13 terminates in the convex portion 12. In addition, the internal diameter of the part located in the convex part 12 among the gates 13 is reducing with the level | step difference with respect to the part located in an upstream.

  Moreover, the inner wall surface 13a located in the shaping | molding part C side among the gates 13 is located in the shaping | molding part C side rather than the outer surface 12a of the convex part 12 in the planar view seen from the Z direction. And in the 1st shaping | molding die 10, the gate 13 and the inside of the shaping | molding part C are formed in the corner | angular part 30 which the outer surface 12a of the convex part 12 mentioned above and the part connected to the outer surface 12a among the mold-matching surfaces 11 make. A gate opening 14A is formed. That is, the gate opening 14 </ b> A is formed so as to straddle the above-described corner 30.

  A portion of the convex portion 12 that is located closer to the second mold 20 than the gate 13 (a portion that is located between the downstream end surface 13b of the gate 13 and the front end surface 12b of the convex portion 12) is orthogonal to the Z direction. The support portion 15 that extends along the direction to hold the gate 13 from the second mold 20 side is configured.

  Thus, the gate opening 14 </ b> A of the present embodiment is defined only by the first mold 10. In this case, of the opening edge of the gate opening 14A, the portion located on the second mold 20 side is a corner formed by the outer surface 12a of the convex portion 12 and the downstream end surface 13b of the gate 13 (the corner of the support portion 15). And the part between the molded product S and the gate part G is cut when the mold is opened.

[Injection molding method]
Next, a manufacturing method (injection molding method) of the molded product S using the mold 1 described above will be described.
First, as shown in FIGS. 1 and 4, the second molding die 20 is brought close to the first molding die 10 along the Z direction by a driving mechanism (not shown) to obtain a clamping state (mold clamping). Process). In the clamped state, the mold-matching surface 21 is abutted against the mold-matching surface 11 of the first mold 10, so that the molding recess 23 of the second mold 20, the mold-matching surface 11 and the protrusion of the first mold 10 A molded portion C for forming the molded product S is defined in a portion defined by the outer surface 12a of the twelve. Further, the convex portion 12 of the first molding die 10 is accommodated in the guide concave portion 24 of the second molding die 20, and the outer side surface 12 a is disposed flush with the inner side surface 23 a of the molding concave portion 23. Thereby, the gate opening 14A of the gate 13 straddles the side surface portion C1 of the molding portion C and the portion facing the molding portion C (opposing portion C2) of the mold matching surface 11 of the first molding die 10. Open.

  Next, the molten resin material is supplied from a supply source (not shown) through the gate 13 (filling step). Specifically, the resin material supplied from the supply source into the gate 13 circulates in the gate 13 along the Z direction. Thereafter, after the resin material hits the downstream end surface 13b of the gate 13, the flow direction is changed toward the gate opening 14A. Then, the resin material flows into the molding part C through the gate opening 14A. At this time, the resin material circulates in the molding part C along the planes of the mold matching surfaces 11 and 21. Thereby, the resin material is filled in the molding part C.

  Thereafter, the mold 1 is cooled to solidify the resin material. Thereby, as shown in FIG. 5, the resin molding 31 according to the inner surface shape of the metal mold | die 1 is shape | molded. That is, in the resin molded body 31, the molded product S molded by the molding portion C and the gate portion G molded by the gate 13 are integrally formed.

FIG. 6 is a process diagram for explaining the mold opening process and is a cross-sectional view corresponding to FIG. 1.
As shown in FIGS. 4 and 6, after the molding material is solidified, the second molding die 20 is separated from the first molding die 10 in the Z direction by a drive mechanism (not shown) (mold opening process). At this time, of the resin molded body 31, the molded product S molded in the molding portion C is held in the molding recess 23 by an undercut portion (not shown) formed in the molding recess 23. On the other hand, the gate portion G molded in the gate 13 in the resin molded body 31 is held in the gate 13 of the first mold 10.

  Therefore, a shearing force acts on the connecting portion J between the molded product S and the gate portion G along the Z direction. Specifically, the molded product S is separated from the first mold together with the second mold 20, while the gate portion G is held by the support portion 15, and movement to the second mold 20 side is restricted. Is done. Therefore, a shearing force acts on the connection portion J from the corner portion of the support portion 15 in a concentrated manner. As a result, the molded product S and the gate portion G are cut at the connection portion J.

FIG. 7 is a process diagram for explaining the extraction process, and is a cross-sectional view corresponding to FIG. 1.
As shown in FIG. 7, after the mold opening process, the molded product S is taken out from the molding recess 23 of the second molding die 20 using an unillustrated ejector pin or the like, and the runner R is removed from the gate 13 (extraction process). . Thereby, the molding of the molded product S is completed.

  Thus, in this embodiment, since the gate opening 14A for supplying the resin material into the molding portion C is formed in the first molding die 10, the mold opening between the first molding die 10 and the second molding die 20 is performed. In the process, the shearing force along the Z direction between the molded product S and the gate part G by the part (corner part of the support part 15) located on the second molding die 20 side of the opening edge of the gate opening 14A. Can be granted. As a result, the gate between the molded product S and the gate portion G can be automatically cut at the timing of mold opening.

In particular, unlike the conventional side gate, it is not necessary to separately provide a gate cut mechanism such as a gate cut pin, so that it is possible to ensure cutting performance while simplifying the mold structure. Therefore, even when the thin molded product S is molded in the molded part C, deformation and warpage of the molded product S can be suppressed and molded into a desired shape. In the present embodiment, since the shearing force is applied to the connection portion J between the molded product S and the gate portion G as described above, the cutting performance is reduced due to the increase in the cross-sectional area of the gate opening 14A compared to the pin gate. Can be suppressed.
Furthermore, by adopting a side gate in which the gate opening 14A opens at the side surface portion C1 of the molding part C, the pressure loss can be reduced and the resin material can be smoothly supplied along the in-plane direction of the molding part C. . Therefore, the filling property can be improved and the occurrence of sink marks or the like can be suppressed as compared with the case where a pin gate is employed.

  Moreover, in this embodiment, since the support part 15 extended in the direction which cross | intersects a Z direction is formed in the part located in the 2nd shaping | molding die 20 side with respect to the gate opening 14A among the 1st shaping | molding die 10. As shown in FIG. In the mold opening process, the gate portion G is pulled away from the second mold 20 together with the first mold 10 while being held by the support portion 15. Thereby, a shearing force can be reliably applied to the connection portion J between the molded product S and the gate portion G, and the molded product S and the gate portion G can be reliably cut.

  Furthermore, the gate opening 14 </ b> A of the present embodiment opens across the side surface portion C <b> 1 of the molding portion C and the facing portion C <b> 2 facing the molding portion C among the mold matching surfaces 11 of the first molding die 10. Therefore, the opening area of the gate opening 14A can be enlarged. Thereby, the pressure loss at the time of passing through the gate opening 14A can be suppressed, and the filling property can be further enhanced.

The technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, the gate opening 14 </ b> A straddles the side surface portion C <b> 1 of the molding portion C and the facing portion C <b> 2 that faces the molding portion C among the mold matching surfaces 11 of the first molding die 10. Although the case where it opens is demonstrated, it is not restricted to this, What is necessary is just to open at the side part C1 at least. In this case, for example, as shown in FIG. 8, the gate opening 14 </ b> B may be configured to open only at the outer side surface 12 a of the convex portion 12 (side portion C <b> 1 of the molding portion C).

Further, the molded product S is not limited to a plate shape, and various shapes can be employed.
Moreover, although embodiment mentioned above demonstrated the case where a resin material was used as a molding material, not only this but a glass-type material, a metal material, etc. may be sufficient, for example.
Furthermore, in embodiment mentioned above, although it was set as the structure provided with the 1st shaping | molding die 10 and the 2nd shaping | molding die 20 as the metal mold | die 1, it is not restricted to this. For example, a mold having a so-called three-plate configuration in which a runner forming plate for forming a runner between the first mold 10 and the first mold 10 is disposed on the opposite side of the first mold 10 from the second mold 20 side. One apparatus may be used.

1 ... Mold (molding die)
DESCRIPTION OF SYMBOLS 10 ... 1st shaping | molding die 14A, 14B ... Gate opening 15 ... Support part 20 ... 2nd shaping | molding die C ... Molding part C1 ... Side part C2 ... Opposite part

Claims (4)

A first mold,
A second molding die that can be brought into contact with and separated from the first molding die, and that defines a molding part between the first molding die, and
The first molding die has a gate opening that opens at least in a side surface portion intersecting a moving direction of the first molding die and the second molding die in the molding portion. Mold.   A portion of the first mold that is located on the second mold side in the movement direction with respect to the gate opening is formed with a support portion that protrudes in a direction intersecting the movement direction and that defines the side surface portion. The molding die according to claim 1, wherein the molding die is formed.   The gate opening is disposed across a corner portion formed by the side surface portion and a facing portion facing the molding portion in the moving direction of the first molding die. The molding die according to claim 1 or 2. A molding method using the molding die according to any one of claims 1 to 3,
A filling step of filling a molding material into the molding part through the gate opening of the first molding die in a state in which the first molding die and the second molding die face each other;
A mold opening step for separating the first mold and the second mold,
In the mold opening step, a shearing force is applied to a molding material located at a boundary portion between the molding portion and the gate opening at a portion of the opening edge of the gate opening located on the second molding die side in the moving direction. And cutting the molding material.

Images