JP2006231781A - Injection mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance commodity properties by preventing a molten resin from turning to the surface side of a molded skin in spite of a side gate system while reducing costs by a simple mold structure. <P>SOLUTION: In a state that the molded skin 15 is set to a first mold 5 and the first mold 5 is clamped to the parting surface 25 of a second mold 11, the recessed part 26 of an extension part 17 is provided corresponding to the thickness of the molded skin 15 so as to correspond to the extension part 17 extending from the outer peripheral terminal part of the molded skin 15 to be positioned outside a cavity 20. A side gate 27 and a runner 29 are formed to the recessed part 26 of the extension part 17 so as to be covered with the extension part 17 of the molded skin 15. A sprue 31 is positioned corresponding to the back of the extension part 17. The molten resin R is injected in the cavity 23 from the side gate 27 through the sprue 31 and the runner 29 by the nozzle 33 of an injection machine to mold a skin integrated molded product 45. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an improvement of an injection mold in which a side gate is provided on the outer periphery of a cavity as a passage for injecting molten resin into a cavity, and particularly relates to measures against resin leakage.

Patent Document 1 discloses an injection mold in which a tunnel gate is provided as a passage for injecting molten resin into a cavity. In this Patent Document 1, the core damper is movably disposed corresponding to the exit of the tunnel gate so as not to be damaged such as the molded skin being damaged due to the injection pressure of the high-temperature molten resin, and is injected from the tunnel gate. The molten resin is introduced into the cavity by bypassing the periphery of the core damper so that the molten resin does not collide linearly with the molded skin.
JP-A-11-277469 (paragraph 0024 column, FIG. 6)

  However, in the above-mentioned Patent Document 1, a core damper and a driving means for moving the core damper are required, which makes the structure complicated and increases the cost.

  When the side gate method is adopted so that the injection pressure of the high-temperature molten resin does not damage the molding skin, the side gate is provided outside the peripheral edge of the cavity, so the melt injected from the side gate into the cavity. There is a possibility that the resin may wrap around to the front side from the outer peripheral end portion of the molded skin, and the molded skin surface side, which is the design surface of the molded skin-integrated molded product, becomes dirty, and the merchantability decreases. FIG. 9 shows an example, and the skin-integrated molded product a is formed by integrally bonding a skin material c to the surface of the base material b, and the molten resin d wraps around and adheres to the surface of the molded skin c corresponding to the side gate. Yes. In FIG. 9, e is a side gate resin solid material solidified by the side gate, f is a runner resin solid material solidified by the runner, and g is a sprue resin solid material solidified by the sprue.

  The present invention has been made in view of such points, and the object of the invention is to improve the merchantability by preventing the molten resin from wrapping around the front side of the molded skin while being a side gate method, and a simple mold. The cost is to be reduced by the structure.

  In order to achieve the above object, the present invention is characterized in that the side gate, the runner and the sprue are covered with a part of the skin material.

  Specifically, the present invention includes a first mold in which a molded skin molded into the surface shape of the skin-integrated molded product is set, and a second mold that forms a cavity between the first mold and the first mold. The following solution is intended for injection molds that form a skin integral molded product by injecting molten resin into the cavity from the side gate outside the cavity periphery through the sprue and runner from the nozzle of the injection machine Measures were taken.

  That is, the invention according to claim 1 is the outer periphery of the molded skin in a state where the molded skin is set on the first mold and closed on the parting surface of the first mold or the second mold. An extension part set recess is provided corresponding to the thickness of the molding skin so as to correspond to the extension part located outside the cavity extending from the terminal part, and the extension part set recess includes the side The gate and the runner are formed so as to be covered with the extending portion of the molding skin, and the sprue is positioned corresponding to the back surface of the extending portion.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, the runner is inclined with respect to the sprue at a predetermined inclination angle.

  According to the first aspect of the present invention, the high-temperature molten resin injected from the nozzle of the injection machine collides with the extension part back surface of the molding skin covering the side gate and the runner on the outer side of the cavity via the sprue, It is injected into the cavity through the runner and side gate along the extension. Therefore, the injection pressure of the high-temperature molten resin does not directly act on the molding skin in the cavity, and the molding skin can be prevented from being damaged by the injection pressure. In addition, since the side gate and runner are covered with the extending part of the molded skin, the molten resin can be reliably prevented from flowing around from the outer peripheral terminal part of the molded skin to the front side and becoming dirty, thereby improving the product quality. Can do. Furthermore, it is only necessary to provide the extension part set recess for setting the extension part of the molding skin in the parting surface of the first mold or the second mold, and the core damper as in Patent Document 1 or the like is moved. It is not necessary to employ driving means, and the cost can be reduced with a simple mold structure.

  According to the invention according to claim 2, since the high-temperature molten resin injected into the runner from the nozzle of the injector through the sprue is weakened in the injection pressure by the runner arranged to be inclined with respect to the sprue, Damage can be eliminated without fail.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an injection mold 1 according to an embodiment of the present invention. The injection mold 1 is fixed to a mounting plate 7 via an ejector plate housing block 9 so as to face the first mold 5 and a first mold (movable mold) 5 fixedly supported on the mounting plate 3. A supported second mold (fixed mold) 11 is provided. The first mold 5 is a cavity mold for molding the front side of a molded product, and a resin molding skin 15 is set on the molding surface 13 thereof. As shown in FIG. 6, the molded skin 15 is formed into a rectangular shallow dish shape according to the surface shape of the skin-integrated molded product in advance by vacuum molding, slush molding, or the like. A flat extending portion 17 extends from the portion. The extension portion 17 is formed by removing the extension portion 17 along the parting surface 19 outside the molding surface 13 (a cavity 23 described later) with the molding skin 15 set on the molding surface 13 of the first mold 5. The outer peripheral end portion of the skin 15 is accommodated in the molding surface 13 (cavity 23).

  On the other hand, the second mold 11 is a core mold that molds the back side of the molded product, and the first mold 5 is brought close to the second mold 11 and closed between the molding surfaces 13 and 21. A cavity 23 is formed in the front. As shown in FIG. 2, the parting surface 25 of the second mold 11 is set from the outer peripheral end portion of the molding skin 15 with the molding skin 15 set on the first mold 5 and closed. A flat extension part set recess 26 is provided corresponding to the thickness of the molding skin 15 so as to correspond to the extension part 17 that extends and is located outside the cavity 23. A narrow side gate 27 and a semicircular runner 29 are continuously formed along the longitudinal direction in the middle of the extension set recess 26 in the width direction, and the side gate 27 is formed at the periphery of the cavity 23. It continues to the outside. Therefore, the side gate 27 and the runner 29 are covered by the extension portion 17 of the molding skin 15 set in the extension portion setting recess 26. Further, a spru 31 is formed in the second mold 11 in the mold opening direction, and one end thereof is continuous with the runner 29, and the runner 29 is inclined with respect to the spru 31 at a predetermined inclination angle. ing. Therefore, the sprue 31 is positioned corresponding to the back surface of the extending portion 17. Further, the other end of the sprue 31 communicates with a nozzle 33 of an injection machine (not shown) inserted in the mounting plate 7 and the nozzle insertion holes 7a, 9a of the ejector plate housing block 9.

  The ejector plate 37 is connected to the tip of the piston rod 39a of the ejector cylinder 39 so as to be able to advance and retreat in the accommodating chamber 35 corresponding to the cavity 23 of the ejector plate accommodating block 9. One end of an ejector pin 41 is fixed to the ejector plate 37, and the other end of the ejector pin 41 passes through the insertion hole 11a of the second mold 11 and protrudes from the molding surface 21 into the cavity 23. Yes. A cooling water passage 43 for circulating the cooling water is provided inside the first mold 5 and the second mold 11 in order to prevent the mold temperature from rising due to the heat effect of the high temperature molten resin R. It is circulated.

  And in order to shape | mold the skin integrated molded product 45 as shown in FIGS. 3-5 using the injection mold 1 comprised in this way, first, in the state which opened the injection mold 1, the shaping | molding skin 15 The molding skin 15 is set on the molding surface 13 of the first mold 5 so that the extension part 17 faces the extension part set recess 26 side of the second mold 11.

  Next, the first mold 5 is brought close to the second mold 11 to close the injection mold 1, and the extension part 17 of the molding skin 15 is set in the extension part set recess 26 of the second mold 11. To do. As a result, the side gate 27 and the runner 29 are covered with the extended portion 17 of the molding skin 15. Further, the sprue 31 is positioned corresponding to the back surface of the extending portion 17.

  Thereafter, high temperature molten resin R is injected into the cavity 23 from the side gate 27 outside the peripheral edge of the cavity 23 through the sprue 31 and the runner 29 from the nozzle 33 of the injection machine, and the molten resin R is cooled and solidified to form the base material 47. A skin-integrated molded product 45 in which the molded skin 15 is integrally joined to the molded body is molded. The molded skin integrated product 45 is attached with a side gate resin solid material 49a solidified by the side gate 27, a runner resin solid material 49b solidified by the runner 29, and a sprue resin solid material 49c solidified by the sprue 31. . These resin solids 49a to 49c are formed after the injection mold 1 is opened and the ejector pin 41 protrudes from the molding surface 21 by the contraction operation of the ejector cylinder 39 to remove the skin integral molded product 45, and then the molding skin 15 Are cut out from the skin-integrated molded product 45 together with the extending portion 17.

  As described above, in this embodiment, the high-temperature molten resin R injected from the nozzle 33 of the injection machine is sprinkled on the back side of the extending portion 17 of the molding skin 15 that covers the side gate 27 and the runner 29 outside the cavity 23. , And then injected into the cavity 23 through the runner 29 and the side gate 27 along the extended portion 17, the injection pressure of the high-temperature molten resin R is linearly applied to the molding skin 15 in the cavity 23. It is possible to prevent the skin material 15 from being damaged by the injection pressure. In particular, since the injection pressure of the high-temperature molten resin injected from the nozzle 33 of the injection machine through the sprue 31 to the runner 29 is weakened by the runner 29 inclined with respect to the sprue 31, damage to the molded skin 15 is ensured. Can be eliminated.

  Further, since the side gate 27 and the runner 29 are covered with the extending portion 17 of the molding skin 15, it is ensured that the molten resin R wraps around from the outer peripheral terminal portion of the molding skin 15 to the front side and the molding skin 15 is not contaminated. The merchantability can be improved.

  Furthermore, the extension part set recess 26 for setting the extension part 17 of the molding skin 15 only needs to be recessed in the parting surface 25 of the second mold 11, and the core damper as disclosed in Patent Document 1 or the like is moved. It is not necessary to employ driving means, and the cost can be reduced with a simple mold structure.

  FIG.7 and FIG.8 shows the perspective view of the circumference | surroundings of the side gate of the skin integral molded product 45 injection-molded in another embodiment. In this embodiment, an extension set recess 26 for setting the extension 17 of the molding skin 15 is formed on the parting surface 19 of the first mold 5. Accordingly, the side gate 27 and the runner 29 are also formed on the parting surface 19 of the first mold 5, and accordingly, the cross-sectional shape of the portion corresponding to the runner 29 of the extension set recess 26 is the cross-sectional shape of the runner 29. A semicircular shape following the above. Naturally, the cross-sectional shape of the portion corresponding to the runner 29 of the extending portion 17 of the molding skin 15 is also semicircular. Others are the same as those in the above embodiment, and the same operational effects can be achieved.

  The injection mold 1 of each of the above embodiments is a mold for injection molding the skin integral molded product 45, but can also be applied to molding a molded product without the molded skin 15. is there.

  The present invention is useful as an injection mold in which a side gate is provided outside the peripheral edge of the cavity as a passage for injecting molten resin into the cavity.

It is sectional drawing of the injection mold which concerns on one Embodiment. It is sectional drawing in the II-II line of FIG. It is a perspective view of the skin integral molded product injection-molded with the injection mold which concerns on one Embodiment. It is sectional drawing in the IV-IV line of FIG. It is sectional drawing in the VV line | wire of FIG. It is a fragmentary perspective view of a shaping | molding skin. It is a perspective view around the side gate of the skin integral molded product injection-molded in another embodiment. It is sectional drawing in the VIII-VIII line of FIG. It is a perspective view which shows the state in which molten resin wraps around the surface of the skin integral molded product by which injection molding was carried out.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Injection mold 5 1st metal mold | die 11 2nd metal mold | die 15 Molding skin 17 Extension part 19,25 Parting surface 23 Cavity 26 Extension part set recess 27 Side gate 29 Runner 33 Nozzle 31 Spru 45 Skin integral molding R Molten resin

Claims (2)

A first mold in which a molded skin formed on the surface shape of the skin-integrated molded product is set, and a second mold that forms a cavity between the first mold and the sprue from the nozzle of the injection machine And an injection mold for injecting molten resin into the cavity from the side gate on the outer periphery of the cavity through the runner to form an integrated skin molded product,
On the parting surface of the first mold or the second mold, the molding skin is set in the first mold and the mold is closed, and is extended from the outer peripheral end portion of the molding skin and located outside the cavity. An extension set recess is provided corresponding to the thickness of the molded skin so as to correspond to the extension, and the side gate and runner are provided in the extension of the molded skin in the extension set recess. An injection mold wherein the sprue is positioned so as to be covered with the back surface of the extending portion. The injection mold according to claim 1,
An injection mold characterized in that the runner is inclined with respect to the sprue at a predetermined inclination angle.

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