JP5018287B2 - Injection mold equipment - Google Patents

Description

  The present invention relates to an injection mold apparatus including a nesting mold and an assembled mold.

  When molding a complex-shaped structure by injection molding, when using an assembled mold that combines multiple molds with different parts to be molded in consideration of the ease of removing the molded product and the accuracy of mold processing There are many.

  FIG. 7 is a cross-sectional view of an essential part of a mold apparatus used when a disk with a shaft hole is molded by an assembled mold. The mold apparatus has a configuration in which a fixed mold 1 and a movable mold 2 that is movable up and down are combined. The fixed-side mold 1 has a spool bush 3 for supplying resin and a runner portion 4 which is a flow path for the resin. On the other hand, the movable mold 2 is filled with the resin supplied via the runner part 4 and has a hollow part 5 for molding a molded product. Further, a vertically movable ejector pin 7 connected to the moving mechanism 6 is inserted into a part of the hollow portion 5, that is, a position 5 a corresponding to the bottom surface of the disk portion. When molding is started, the tip of the ejector pin 7 does not protrude from the position 5a and forms a part of the bottom surface.

  After injecting and filling the resin into the cavity 5 via the spool bush 3 and the runner part 4, the resin is cooled to a certain temperature. Next, the runner part 4 is cut and separated from the molded product by lowering the movable mold 2 with the contact surface 8 between the fixed mold 1 and the movable mold 2 as a parting line, Expose the top of the molding. And the ejector pin 7 is raised and the molded product is pushed up, whereby the molded product is removed from the cavity 5 to complete one cycle of molding.

As prior art document information relating to the invention of this application, for example, Patent Document 1 is known.
Japanese Patent Laid-Open No. 2002-210787

  In the above-described mold apparatus, for example, when unevenness is formed on the side surface of the molded product, the unevenness interferes and cannot be detached from the cavity 5 and cannot be removed. It is necessary to configure with possible molds. In such a case, a separating mechanism for these assembled molds and a separating mechanism for the movable mold 2 are required, and further, since these separating mechanisms are operated in synchronization, there is a problem that the entire mold apparatus becomes complicated.

  Therefore, an object of the present invention is to reliably separate molds with a simple configuration that does not require synchronization.

  In order to achieve the above object, the first separation surface has a first cavity for forming a part of a molded product, and the first and second movable in combination with the first separation surface. In combination with two lower molds and the first cavity part, the second mold part has a second cavity part to be a cavity part for forming the entire molded product. The upper and lower movable molds combined with the top surface as a second separation surface, and the first and second lower molds and ejector pins that are movable up and down, the first and second The lower mold is provided with a through-hole penetrating to the second separation surface directly below the upper mold with the first separation surface approximately as the center, and an ejector pin is inserted into the through-hole to be raised. After separating from the second separation surface by pressing a part of the upper mold, First by further increasing the Kutapin, in which the second lower mold to be separated into left and right first separation surface taking out the molded product.

  The mold apparatus for injection molding according to the present invention includes first and second lower molds that can be freely opened and closed in combination on the first separation surface, and the top surfaces of these first and second lower molds. The upper mold that can be moved up and down combined as two separation surfaces constitutes a cavity for molding a molded product therein. Furthermore, this mold apparatus is movable freely up and down inserted through the through hole that reaches the second separation surface with the first separation surface substantially as the center at a symmetrical position with the hollow portion as the center. Ejector pin is provided. The through hole is disposed immediately below the upper mold, and lifts the ejector pin to bring it into contact with the upper mold and push it up to separate the upper mold from the second separation surface. And by further raising the ejector pin as it is, the first and second lower molds are separated to the left and right on the first separation surface, so only by the operation of the ejector pin, with a simple configuration that does not require synchronization, Even if it is a molding of a complicated shape, there exists an effect which can isolate | separate a metal mold | die reliably.

  Details of the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view for explaining an example of a molded product molded by the injection molding die apparatus of the present invention. After melting a thermoplastic resin such as PPS or PC or an engineering plastic such as a liquid crystal polymer, it is injected and filled into the cavity inside the mold through the runner 9, and becomes a product at the tip of the runner 9. A substantially cylindrical shaped product 10 is formed.

  The molded product 10 in the present embodiment has an annular concave groove 10a in a part of its outer surface. Thus, when molding the molded product 10 having the concave groove 10a, taking into account removal from the mold, a mold that can be divided in the left-right direction for molding the outer surface, and the top surface portion of the molded product 10 A mold assembly is used in which at least three molds are combined with a mold for molding 10b.

  FIG. 2 is an external perspective view for explaining the main part of the injection molding die apparatus according to the present embodiment. From the bottom, first and second lower molds 13 and 14 which are sandwiched between side slides 11 and combined by a first separation surface 12 from below, and these first and second lower molds 13. , 14 and the first and second plates 15 and 16, and the heating means 17, which is placed on the second plate 16 and made of a sheathed heater, a ceramic heater, or the like. (Not shown) and a hot runner 18 for injecting a melted resin. Cavities are formed in the first and second lower molds 13 and 14, respectively. By combining with the first separation surface 12, a part (side surface part) of the molded product 10 is formed. A first cavity is formed. In addition, an upper mold that is combined with the first and second lower molds 13 and 14 to form an entire molded product 10 is provided inside the first plate 15. . Next, the assembled mold will be described.

  FIG. 3 is an AA-A cross section of FIG. 2, that is, an enlarged cross-sectional view of the mold apparatus for injection molding, particularly the mold assembly, on the first separation surface 12.

  A cavity portion 19 is formed in the first lower mold 13, and the second lower mold 14 has the same configuration although not shown. The first and second lower molds 13 and 14 are combined so as to oppose each other at the first separation surface 12 to thereby form a first part for molding the side surface portion of the cylindrical molded product 10 (FIG. 1). The cavity 20 is configured. In the present embodiment, since the molded product 10 has a substantially cylindrical shape, the inside of the molded product 10 has a bottomed cylindrical shape by inserting a slide pin 21 into the first cavity 20.

  Further, an upper mold 23 held by a holding plate 22 is provided on the top surface portion of the first cavity portion 20, and the top surface portions of the first and second lower dies 13, 14 are used as a second separation surface 24. It is mounted and fixed as. The upper mold 23 facing the second separation surface 24 is formed with a second cavity 25 for molding the top surface portion of the molded product 10, and the first and second cavities 20, In combination with 25, a cavity 19 for molding the entire molded product 10 is formed. By filling the hollow portion 19 with the resin injected through the hot runner 18 through the runner portion 9, a substantially cylindrical shaped product 10 is formed. As described above, in the present embodiment, the molded product 10 is molded by a combined mold in which three molds of the first and second lower molds 13 and 14 and the upper mold 23 are combined. is there.

  The holding plate 22 and the upper mold 23 are pressed and held by the first plate 15 against the second separation surface 24, and the upper mold 23 is simultaneously pressed by the second plate 16 via the holding piece 26. Pressed and held. Furthermore, the first and second plates 15 and 16 are each provided with a pressing pin 28 having a pressing mechanism 27 such as a spring. The pressing pin 28 presses and holds the pressing plate 22 with a constant force. Yes.

  Further, the first and second lower molds 13 and 14 are provided with a through-hole 29 that reaches the top surface portion with the first separation surface 12 as a substantial center. An ejector pin 30 that is movable up and down is inserted into the through hole 29. In the present embodiment, the through holes 29 and the ejector pins 30 are arranged at both ends of the pressing plate 22 so as to be symmetric with respect to the hollow portion 19. On the inner surface of the through hole 29 close to the tip of the ejector pin 30 and the second separation surface 24, inclined surfaces 31 and 32 having substantially the same inclination angle and capable of contacting each other are provided. When the molding die is separated and the molded product 10 is taken out from the internal cavity 19 after the molding is completed, the ejector pin 30 is raised to push the top surface against the bottom surface of the pressing plate 22 and push it up. Thus, the upper mold 23 is first separated from the first and second lower molds 13 and 14 from the second separation surface 24. Then, by further raising the ejector pin 30, the inclined surface 31 provided at the tip of the ejector pin 30 is brought into contact with the inclined surface 31 provided on the inner surface of the through-hole 29, thereby causing the pressing generated at the time of contact. The pressure is distributed in the horizontal direction, and the first and second lower molds 13 and 14 are separated to the left and right by the first separation surface 12 by the force. Next, details of the separation operation will be described.

  FIG. 4 (a) is a perspective view of the inside of the injection mold apparatus of the present embodiment, that is, the assembled mold. In order to explain the separating operation of the assembled mold, the approximate center of the ejector pin 30 is shown. A part of the passing surface was cut out to be a sectional view. FIG. 4B is an enlarged view of the tip of the ejector pin 30 in the cut-out cross section indicated by the circle B in FIG.

  First, the molten resin is injected into the cavity 19 (FIG. 3) in the assembled mold constituted by the upper mold 23, the first and second lower molds 13, 14 through the runner part 9. After filling, cool to a constant temperature. Next, the ejector pin 30 is raised and its tip is brought into contact with the bottom surface of the pressing plate 22 and pressed. Further, the upper die 23 is separated from the second separation surface 24 together with the pressing plate 22 by raising the ejector pin 30. At this time, together with the pressing plate 22, the pressing mechanism 27 and the pressing pin 28 are also separated and removed from the first and second lower molds 13 and 14. By doing so, as shown in FIG. 5A, the runner portion 9 (resin formed along the runner portion 9) and the top surface portion 10 b of the molded product 10 are exposed on the second separation surface 24. At this time, as shown in FIG. 5 (b), the inclined surface 32 having substantially the same inclination angle C is formed on the tip portion of the ejector pin 30 and the inner surface of the through hole 29 in the vicinity of the second separation surface 24. , 31 are provided. When the upper mold 23 is separated, the ejector pin 30 is raised in a range where the inclined surfaces 31 and 32 do not contact each other. In this embodiment, two ejector pins 30 are provided at symmetrical positions with the cavity 19 in between. Thus, when providing the several ejector pin 30, it can be made to isolate | separate reliably, without damaging the upper metal mold | die 23 by making it contact | abut to the press plate 22 and pushing up simultaneously.

  Next, the ejector pin 30 is raised as it is, and the inclined surface 31 on the inner surface of the through hole 29 and the inclined surface 32 at the tip of the ejector pin 30 are brought into contact with each other. Then, by further raising the ejector pin 30, the force in the vertical direction (z direction) is distributed in the horizontal direction (x direction), and the first and second lower molds 13, 14 are moved to the first by the distributed force. The molded product 10 is taken out from the cavity 19 by being separated from the separation surface 12 in the horizontal direction. What is important at this time is the inclination angle C of both the inclined surfaces 31 and 32 provided in the ejector pin 30 and the through hole 29 (FIG. 5B). By making the inclination angle C less than 45 degrees, the force distributed in the horizontal direction becomes larger, but by taking the frictional force of the inclined surfaces 31 and 32 into consideration, the inclination angle C is made 10 degrees or less. The first and second lower molds 13 and 14 can be reliably separated left and right by the first separation surface 12 without pushing up. In addition, the surface roughness of the inclined surfaces 31 and 32 can separate the 1st, 2nd lower metal mold | die 13 and 14 more reliably by making it approximate to a mirror surface.

  Thus, after first separating the upper mold 23 on the second separation surface 24, the first and second lower molds 13, 14 are separated on the first separation surface 12, The upper mold 23 and the first and second lower molds 13 and 14 do not interfere during the separation operation. Therefore, breakage of these molds can be prevented and maintenance frequency can be reduced, so that productivity can be improved.

  Further, as the moving mechanism of the ejector pin 30, an impact can be given when the inclined surfaces 31 and 32 are brought into contact with each other by using a cam mechanism or the like, so that the outer surface of the molded product 10 can be applied. The first and second lower molds 13 and 14 can be reliably separated even if the molded product 10 is uneven and difficult to release due to the biting of the resin.

  The present embodiment is an example of a substantially cylindrical shaped product 10, but is applicable without being limited to its outer shape such as a column, a prism, or a square cylinder.

  In the present embodiment, the upper mold 23 is held by the holding plate 22, but the upper mold 23 is held by the first plate 15, and the bottom portion of the upper mold 23 is directly attached by the ejector pins 30. It may be pressed and separated.

  By using the above-mentioned injection molding die device, even a complex shaped product with irregularities formed on the outer surface can be reliably configured with a simple configuration that does not require synchronization and only the operation of the ejector pin. The mold can be separated.

  The mold apparatus for injection molding according to the present invention includes first and second lower molds that can be freely opened and closed in combination on the first separation surface, and the top surfaces of these first and second lower molds. The upper mold that can be moved up and down combined as two separation surfaces constitutes a cavity for molding a molded product therein. Furthermore, this mold apparatus is movable freely up and down inserted through the through hole that reaches the second separation surface with the first separation surface substantially as the center at a symmetrical position with the hollow portion as the center. Ejector pin is provided. The through hole is disposed immediately below the upper mold, and lifts the ejector pin to bring it into contact with the upper mold and push it up to separate the upper mold from the second separation surface. And by further raising the ejector pin as it is, the first and second lower molds are separated to the left and right on the first separation surface, so only by the operation of the ejector pin, with a simple configuration that does not require synchronization, Even if it is a molded product of a complicated shape, since it has the effect of being able to reliably separate the mold, it is useful for an injection mold apparatus comprising a nested mold or an assembled mold.

External perspective view for explaining an example of a molded product molded using the injection molding die apparatus of the present invention FIG. 3 is an external perspective view for explaining an injection mold apparatus according to the present invention. Enlarged sectional view for explaining the internal structure of the same injection mold apparatus (A) Perspective view of a partially cut-out mold device for explaining the mold separation operation, (b) Enlarged sectional view of the cut-out portion of FIG. 4 (a) (A) Perspective view of partly cut out of an injection mold apparatus for explaining the mold separation operation, (b) Enlarged sectional view of the notched part of FIG. 5 (a) (A) Partially cutaway perspective view of a mold apparatus for injection molding explaining the mold separation operation, (b) Enlarged sectional view of the cutout portion of FIG. 6 (a) Sectional drawing explaining the conventional mold apparatus for injection molding

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Molded article 12 First separation surface 13 First lower mold 14 Second lower mold 19 Cavity 20 First cavity 22 Holding plate 23 Upper mold 24 Second separation surface 25 Second cavity Part 29 Through-hole 30 Ejector pin 31, 32 Inclined surface

Claims (4)

The first and second lower molds that have a first cavity for forming a part of the molded product on the first separation surface, and are movable in the left and right combination with the first separation surface, In combination with the first cavity, the second cavity is a cavity for forming the entire molded product, and the top surface of the first and second lower molds is the second separation surface. And an upper die that can be moved up and down, and an ejector pin that is inserted into the first and second lower die and can be moved up and down. A through hole penetrating up to the second separation surface directly below the upper mold with the separation surface of the upper part as a center, an ejector pin is inserted into the through hole and raised, and a part of the upper mold is placed at the tip of the through hole. After separating from the second separation surface by pressing, the ejector pin is further raised First the Rukoto, injection mold apparatus, wherein a second lower mold to be separated into left and right first separation surface taking out the molded product. 2. The mold apparatus for injection molding according to claim 1, wherein the ejector pins and the through holes are provided at a plurality of symmetrical positions with the hollow portion as a substantial center. The mold apparatus for injection molding according to claim 1 or 2, wherein a part of the tip of the ejector pin and a part of the inner surface of the through hole are provided with inclined surfaces that can contact each other. The injection mold apparatus according to claim 3, wherein an inclination angle of the inclined surface is 10 degrees or less.

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