JP5366004B2 - Multi-layer injection mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold for the laminated injection molding which does not leave a gate trace at a design surface side of a secondary molding, and can obtain stably the wall thicknesses of a primary molding and the secondary molding of the standing surface of the molding. <P>SOLUTION: In the mold for laminated injection molding, the primary molding is injection-molded through a primary injection gate by a primary injection molding unit after a primary mold clamping using a product core mold and a plurality of product cavity molds different in product design shape. After a predetermined cooling holding time, a predetermined distance is mold-opened, the product cavity mold is replaced in a state that the primary molding is left in the product core mold. Thereafter, a secondary mold clamping is carried out and a new product cavity is formed. A secondary injection molding is carried out at the surface side of the primary molding through a secondary injection gate by a secondary injection molding unit to the formed product cavity, by which a secondary molding is laminated on the primary molding to obtain an integrated laminate molding. A projection blocking the secondary injection gate at the primary clamping state is provided on a primary molding cavity surface. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a molding die used for laminate molding in which a resin is injection molded into a laminated state to obtain a laminated product, and in particular, a multilayer injection molding die for exchanging a mold when forming a second layer. Regarding type.

A molding die for obtaining a laminated product by injection molding a resin into a laminated state by primary molding and secondary molding is disclosed, for example, in Patent Document 1.
This molding die is composed of a set of fixed mold and movable mold, and by using a slide core that interlocks with the mold opening during secondary molding after primary molding, the thickness of the secondary molded body is partially Can be made larger. Then, the resin is supplied to the mold by using a double-structure nozzle, and filling the cavity with the primary molding resin and the secondary molding resin sequentially from one point gate provided on the fixed mold.
Molded products obtained using this mold are molded using the same gate for primary molding and secondary molding, so the primary molding layer and secondary molding layer are mixed in the secondary molding, and the quality is good. It is difficult to mold a laminated product, and a gate mark remains on the design surface on the surface side of the secondary molded body. And there exists a problem that the thickness of the standing surface (direction which cross | intersects a mold opening direction) of a secondary molded object cannot be enlarged as a whole.

Japanese Patent Application Laid-Open No. 2004-228561 discloses a mold for lamination molding that solves the above-mentioned problems. This molding die is composed of a set of fixed mold and movable mold, and has a gate that can be separately injected and filled with resin of primary molding and secondary molding in the cavity, and only the dimension corresponding to the thickness of the primary molded body With the mold open, the tip of the gate for injecting the resin of the secondary molded body is in contact with the surface on the movable mold side, and the primary molded body can be prevented from entering the gate of the resin. Then, in a state where the resin of the primary molded body is flowable, the injection of the resin of the secondary molded body is started at a position adjacent to the resin of the primary molded body while further opening the mold, and the resin is opened corresponding to the thickness of the molded product. The molded product is obtained by continuing the injection of the primary molding resin and the secondary molding resin until the inside of the cavity is filled.
The molded product obtained using this mold passes through the primary molded body and supplies the resin from the back side of the secondary molded body, so that the gate mark remains on the design surface on the front side of the secondary molded body. There is no. In addition, since the control range of the thickness of the molded product is wide, there is no uneven flow between the primary molded product and the secondary molded product, and the overall thickness of the standing surface (direction intersecting the mold opening direction) of the molded product is increased. be able to.
However, it is necessary to adjust the injection conditions so that the two-layer state can be maintained up to the end of the molded product, and the wall thickness of the primary molded product and secondary molded product of the molded product's standing surface (direction intersecting the mold opening direction) Therefore, there is a problem that the shape of the molded product is limited.

JP-A-3-053917 JP-A-9-085779

  Since the present invention is made in view of the problems of the conventional mold for lamination molding that is formed of the above-described set of molds and molds the second layer by opening the mold, the design of the secondary molded body Laminated injection molding that does not leave a gate mark on the surface side and can stably obtain the wall thickness of the primary molded body and the secondary molded body of the standing surface (direction intersecting the mold opening direction) of the molded product The purpose is to provide a metal mold.

The laminated injection mold of the present invention includes one product core mold, a plurality of product mold molds having different product design shapes, a plurality of injection units for measuring and injecting different molten resins, the product core mold, A mold clamping device that fixes the product mold and allows the mold to be opened and closed, and after the primary mold clamping, the primary molded body is injection-molded through a primary injection gate by a primary molding injection unit, and a predetermined cooling holding time is obtained. Later, the mold is opened for a predetermined distance, then the product mold is replaced while the primary molded body remains in the product core mold, and then the secondary mold is clamped to form a new product on the whole or a part of the surface side of the primary molded body. A secondary formed body is laminated and integrated on the surface side of the primary molded body by forming a cavity and performing secondary injection molding via a secondary injection gate by a secondary molding injection unit into the formed product cavity. Laminated A laminate injection mold to obtain the goods, the projection in a state of the primary mold clamping block the secondary injection gate is provided in the primary molding product cavity mold surface.

  The protrusion is a laminated injection mold having a conical portion in contact with the molten resin during injection molding after primary mold clamping and a cylindrical shape in the portion inserted into the product core mold.

  Using a single product core mold and a plurality of product mold molds, primary molding is performed by performing primary molding in a state where the secondary injection gate is closed with protrusions provided on the primary mold mold surface of the product mold mold mold, and then a primary molded body is obtained. Since the product mold is changed and the secondary molded body is formed from the back side of the primary molded body to the front side of the primary molded body, a laminated injection molded product is obtained, so the gate is placed on the design surface of the secondary molded body. No traces will remain. In addition, since it has a structure having a product mold of a primary molded body and a secondary molded body having different product design shapes, the primary molded body and the secondary molded body of the standing surface (direction intersecting the mold opening direction) of the molded product The wall thickness can be obtained stably.

Since the shape of the protrusion is a conical shape that comes into contact with the opening of the secondary injection gate of the product core mold, the molded product does not peel from the product core mold when the mold is opened after the primary molded body is molded. Further, in the cylindrical shape in which the shape of the base of the projection is a truncated cone and the tip of the projection is inserted into the opening of the secondary injection gate of the product core mold, the secondary injection is performed even if the thickness of the primary molded body is varied. It is possible to secure a resin flow path when performing the above.
The protrusion has a simple structure and does not increase the cost of the mold.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of the present invention and is a cross-sectional view of a mold when a primary molded body is molded. It is sectional drawing when shape | molding a secondary molded object with the metal mold | die of FIG. The other embodiment of the present invention is shown, and is a cross-sectional view of a mold when a primary molded body is molded. It is sectional drawing when shape | molding a secondary molded object with the metal mold | die of FIG. It is sectional drawing of the projection made into the cone shape contact | abutted with the opening part of the secondary injection gate of a product core type | mold at the front-end | tip part. It is sectional drawing of the protrusion which made the base a truncated cone and made the front-end | tip part cylindrical shape.

1 and 2 show an embodiment of the present invention. A mold 10 for a laminated injection-molded product has a product core mold 11 attached to a fixed plate of a mold clamping mechanism of a molding apparatus (not shown) and a movable plate (not shown). A plurality of product mold molds having different product design shapes attached to an intermediate plate 12 which is slidably engaged and slidable, and which is rotatably arranged with the axis of the molding device as a horizontal plane or a vertical plane, that is, primary molding The product product mold 13 and the secondary product product mold 14 are basically configured.
FIG. 1 shows a state in which a product core mold 11 and a product mold 13 for primary molding are closed. In the product core mold 11, a resin serving as a passage for supplying molten resin to a cavity for molding a primary molded body 15. A resin flow path 18 serving as a path for supplying molten resin to a cavity for molding the flow path 16 and the secondary molded body 17 is provided.
Reference numeral 20 denotes a center of rotation of the intermediate plate 12 that rotates in a mold open state. In FIGS.

A primary injection gate 21 and a secondary injection gate 22 are arranged on the product mold surface side of the resin flow paths 16 and 18 of the product core mold 11. The opening of the secondary injection gate 22 is in contact with the protrusion 23 provided on the cavity surface 13a of the primary molding product mold 13 while the primary molding product mold 13 and the product core mold 11 are closed. The secondary injection gate 22 is closed to prevent the molten resin from leaking to the secondary injection gate 22 when the primary molded body 15 is molded.
In the embodiment, the resin flow paths 16 and 18 are preferably constituted by hot runners, and the primary injection gate 21 and the secondary injection gate 22 are preferably a hot tip or a valve gate. The secondary injection gate 22 is configured not to interfere with the protrusion 23 when the mold is closed.

The primary molding product mold 13 has a cavity surface 13a, and the secondary molding product mold 14 has a cavity surface 14a having different product design shapes.
As shown in the drawing, molten resin is supplied to the mold cavity from the primary molding injection unit 31 used for molding the primary molded body 15 and the secondary molding injection unit 32 used for molding the secondary molded body 17. In any of the injection units, when the screws 33 and 34 are rotationally driven, a predetermined amount of the resin molding material in the barrels 35 and 36 is heated and melted and stored. The cavity is injected and filled into the cavity through 37 and 38.

FIG. 1 shows a state in which the product core mold 11 and the primary molding product cavity mold 13 are closed, and the screw 33 of the primary molding injection unit 31 moves forward to mold the primary molded body 15. As described above, since the secondary injection gate 22 is blocked by the protrusion 23 when the primary molded body 15 is molded, the injection-filled molten resin may flow back to the secondary injection unit 32 side. Absent.
FIG. 2 shows that the product core mold 11 and the secondary molding product mold 14 are closed with the primary molded body 15 left, and the screw 34 of the secondary molding injection unit 32 moves forward to form the secondary molded body. 17 shows a state in which the molded body 17 is laminated and integrated with the primary molded body 15. Since the projection 23 forms a passage hole for the molten resin for secondary injection in the secondary injection gate 22 portion of the primary molded body 15, secondary injection is performed through this hole. Thus, since it was set as the structure which injects and fills the molten resin of the secondary molded object 17 from the back surface side of the primary molded object 15, a gate trace is not produced on the design surface.

3 and 4 show another embodiment of the present invention, wherein a laminated injection molded product mold 50 includes a product core mold 51 attached to a fixed plate of a mold clamping mechanism of a molding apparatus (not shown), and a product for primary molding. The slide mold 52 basically includes a cavity and two cavity surfaces 52a and 52b, which are product cavities for secondary molding. The slide die 52 is attached to an intermediate plate 53 having slide means of the slide die 52 provided on a movable plate of a molding apparatus (not shown), and can be brought into contact with and separated from the product core die 51.
FIG. 3 shows a state where the product cavities for primary molding of the product core mold 51 and the slide mold 52 are closed. In the product core mold 51, a resin flow serving as a passage for supplying a molten resin to the cavity serving as the primary molded body 55 is shown. A resin flow path 58 serving as a path for supplying the molten resin to the path 56 and the cavity serving as the secondary molded body 57 is provided. The slide mold 52 has a configuration in which the primary molding cavity and the secondary molding cavity are integrally formed. However, the slide mold 52 may have a configuration in which each is an independent mold and the molds are connected and integrated.

A primary injection gate 61 and a secondary injection gate 62 are disposed on the product mold surface side of the resin flow paths 56 and 58 of the product core mold 51. The opening of the secondary injection gate 62 closes the secondary injection gate 62 in contact with the protrusion 63 provided on the primary molding cavity surface 52a in a state in which the slide mold 52 and the product core mold 51 are closed. When molding 55, molten resin is prevented from leaking to the secondary injection gate 62 side.
In the embodiment, the resin flow paths 56 and 58 are preferably constituted by hot runners, and the primary injection gate 61 and the secondary injection gate 62 are preferably a hot tip or a valve gate. The secondary injection gate 62 is configured not to interfere with the protrusion 63 when the mold is closed.

  As shown in the figure, molten resin is supplied to the mold from the primary molding injection unit 31 used for molding the primary molded body 55 and the primary molding injection unit 32 used for molding the secondary molded body 57. In any of the injection units, when the screws 33 and 34 are rotationally driven, a predetermined amount of the resin molding material in the barrels 35 and 36 is heated and melted and stored, and the predetermined amount of molten resin is moved to the nozzle by the forward movement of the screws 33 and 34. The cavity is injected and filled into the cavity through 37 and 38.

FIG. 3 shows a state in which the product core mold 51 and the primary molded product cavity of the slide mold 52 are closed, and the screw 33 of the primary molding injection unit 31 is advanced to mold the primary molded body 55. . As described above, since the secondary injection gate 62 is blocked by the protrusion 63 when the primary molded body 55 is molded, the injection-filled molten resin may flow back to the secondary injection unit 32 side. Absent.
In FIG. 4, the product core die 51 and the product cavity for secondary molding of the slide die 52 are closed, the screw 34 of the injection unit 32 for secondary molding advances, and the secondary molded body 57 is molded. The state where the body 55 is laminated and integrated is shown. Since the projection 63 forms a passage hole for the molten resin for secondary injection in the secondary injection gate 22 portion of the primary molded body 55, secondary injection is performed through this hole. Thus, since it was set as the structure which injects and fills the molten resin of the secondary molded object 57 from the back surface side of the primary molded object 55, a gate trace is not produced on the design surface.

FIG. 5 is a cross-sectional view of a conical protrusion 23 that contacts the opening of the secondary injection gate 22 of the product core mold 11 provided on the primary mold cavity surface 13a of the primary mold product mold 13 in FIGS. Is shown.
As shown in the figure, with the mold closed, the outer peripheral surface of the projection 23 is inserted into the opening of the secondary injection gate of the product core mold 11 and contacts the edge of the gate to close the gate. The resin is prevented from leaking from the secondary injection gate 22 when the primary molded body 15 is molded. Further, when the primary molded body 15 is cooled and solidified, a resin flow path for secondary molding is formed by the projections 23 of the truncated cone. The molten resin for secondary molding is filled into the cavity through this resin flow path.

FIG. 6 shows a cross section of the protrusion 24 whose base is a truncated cone and whose tip is cylindrical. When filling the cavity with resin for the primary molded body 15 using a mold having an inlay structure (push-in structure), the cavity is enlarged and the primary molded body 15 is foamed, or the mold cavity is formed by an injection press molding method. When molding to increase the thickness of the molded product by enlarging, the gate part will not be released from the gate hole even if the mold moves in the mold opening direction, and the molten resin leaks from the secondary gate. It was set as the structure which can prevent.
A configuration in which the product core-type gate tip can be inserted through the cylindrical portion of the protrusion 24 is preferable. Although the protrusions 23 and 24 have been described with reference to the laminated mold shown in FIGS. 1 and 2, the present invention is not limited to this, and can be applied to the laminated mold 50 using the slide mold 52 shown in FIGS. .
In the present invention, the protrusions 23, 24, 63 are formed integrally with the primary molding cavity surface. However, the projections 23, 24, 63 may be formed separately and provided detachably on the mold cavity surface.

Next, a molding method using the mold shown in FIGS. 1 and 2 according to the embodiment of the present invention will be described. The intermediate plate 12 is rotationally driven at the mold opening position of the movable platen of the molding apparatus so that the product mold 13 for primary molding and the product core die 11 face each other, and the movable platen 12 is moved forward to perform mold clamping. In this state, the secondary molding injection gate 22 provided in the product core mold 11 is closed by the projection 23 arranged on the primary molding cavity surface of the primary molding product mold 13. The primary molding injection unit 31 stores a molten resin set in advance to a predetermined filling amount. The molten resin is filled into a primary molding cavity formed by moving the screw 33 forward and closing the mold. The molded body 15 is molded. At this time, since the secondary molding injection gate 22 is blocked by the projection 23, the molten resin does not leak to the gate side. After the elapse of a predetermined cooling time, a mold opening operation is performed while the primary molded body 15 remains in the product core mold 11, and the primary molding product mold 13 is moved backward to a predetermined mold opening position. A resin flow path is formed by the protrusions 23 at the secondary injection gate 22 portion of the primary molded body 15.

Next, the intermediate plate 12 is rotationally driven to move the secondary molding mold product 14 to a position facing the product core die 11. The intermediate plate 12 is again moved forward to perform mold clamping. As a result, the cavity of the secondary molded body 17 is formed by the primary molded body 15 and the secondary molding product mold 14. In the secondary molding injection unit 32, a molten resin set in advance to a predetermined filling amount is stored, and the molten resin is filled into a cavity for secondary molding formed by moving the screw 34 forward and closing the mold. A laminated molded product in which the primary molded body 15 and the secondary molded body 17 are integrated is obtained. Molding is completed by performing a mold opening operation after a predetermined cooling time elapses and taking out the laminated molded product from the mold. By repeating the above-described operation, it is possible to obtain a laminated molding continuously.

In the above-described mold, the mold mold 13 shown in FIGS. 3 and 4 is used in which the mold mold 13 for primary molding and the mold mold 14 for secondary molding are exchanged by rotating the intermediate plate. In the conventional molding method, the primary molding cavity surface and the secondary molding cavity surface are exchanged by a slide mechanism provided on the intermediate plate 53 at a predetermined mold opening position, and the other operation steps are the same.
Since the laminated molded product obtained using the mold for molding and the molding method of the present invention is configured to mold the secondary molded body from the back side of the primary molded body, the gate mark is formed on the design surface of the secondary molded body. Will not occur. In addition, since the mold for forming the primary molded body and the mold for forming the secondary molded body are exchanged to form a laminate, the product thickness on the surface of the molded product (direction intersecting the mold opening direction) In addition, the product thickness in the mold opening direction can be set freely.

  The mold is moved in the mold opening direction, the cavity is enlarged, and a conventional second layer mold is formed. The base material is rigid, and the surface layer, which is the design surface, is made of, for example, an elastomer. In order to form soft resin by foaming so as not to leave a gate mark on the design surface of a laminated molded product with a soft feeling, first (primary molding), the surface layer side is molded first, and then the base material side is molded. In this case, molding failure such as deformation occurs due to the effect of secondary molding resin pressure on the surface layer, and it is difficult to obtain a desired laminated molded product.

  However, in the mold for lamination molding of the present invention, since the base material is primary molded and then the surface layer is secondary molded, it is possible to obtain a multilayer molded product having a desired soft feeling and having no gate trace on the surface layer. it can. Further, in the mold for laminated molding of the present invention, the thickness of the molded product in the mold opening direction, the mold opening direction, and the crossing direction (the surface of the molded product) can be freely set. Since there is a high degree of freedom in the combination of the shapes of the molded body and the secondary molded body, restrictions on the shape of the laminated molded product can be reduced.

10, 50 Multilayer mold 11, 51 Product core mold 12 Intermediate plate 13 Primary mold product mold 13a, 52a Primary mold cavity surface 14 Secondary mold product mold 15, 55 Primary molded body 17, 57 Secondary mold Molded bodies 21, 61 Primary injection gates 22, 62 Secondary injection gates 23, 24, 63 Protrusions 31 Primary molding injection unit 32 Secondary molding injection unit 52 Slide mold

Claims (1)

  One product core mold, a plurality of product mold molds having different product design shapes, a plurality of injection units for measuring and injecting different molten resins, and the product core mold and the product mold mold can be fixed and opened and closed. The primary molded body is injection-molded through a primary injection gate by a primary molding injection unit after the primary mold clamping, and after a predetermined cooling holding time, the mold is opened for a predetermined distance, and then the primary molded body The product mold is exchanged while leaving the product core mold, and then the secondary mold is clamped to form a new product cavity on the whole or a part of the surface side of the primary molded body. Multi-layer injection molding gold for obtaining a multi-layer molded product by integrating the secondary molded body on the surface side of the primary molded body by secondary injection molding via a secondary injection gate by an injection unit for secondary molding. In the mold Thus, a projection that closes the secondary injection gate in the state of the primary mold clamping is provided on the surface of the product mold for primary molding, and the projection is conical at the portion where the molten resin contacts during injection molding after the primary mold clamping. A layered injection mold characterized in that the portion inserted into the product core mold is cylindrical.

Images