JP2015131441A - Mold equipment for injection molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a molding to be taken out properly by a knockout pin, without applying damage to an undercut part.SOLUTION: A slide piece 4 projects from a piece storage part 33 to a first mold 2 side by elasticity of an elastic member 5, following to mold opening of a mold device 1, and an inner wall part 13 and an undercut part 14 of a molding 10 are peeled from a molding recess part 31 of a second mold 3. Then the inner wall part 13 is inwardly shrunk, and following to this, the undercut part 14 is easily peeled from an undercut molding part 42 of the slide piece 4 to the second mold 3 side. Therefore, by projecting the molding 10 to the first mold 2 side from the slide piece 4, by a knockout pin 7, the undercut part 14 of the molding 10 is bent so that the undercut 14 is properly peeled from the undercut molding part 42 without receiving damage, so that the molding 10 can be taken out from the slide piece 4 to the first mold 2 side, so that the molding 10 can be taken out by the knockout pin 7, properly.

Description

  The present invention relates to a mold apparatus for injection molding.

  The undercut processing mechanism of the injection molding disclosed in Patent Document 1 is the first after the first split core moves from the molding position toward the diameter of the undercut portion toward the axis of the undercut when the molded product is die-cut. By moving the two-divided core in the tilt direction from the molding position, the molded product is removed from the mold apparatus.

  By the way, as shown in FIG.5 and FIG.6, injection molding of the molded article 10 which has the undercut part 14 between the outer wall part 12 and the inner wall part 13 was tried. Explaining the attempt, the mold apparatus 15 is composed of the first mold 16 and the second mold 17 as indicated by the phantom lines in FIG. 6 and the undercut molding portion 18 of the mold apparatus 15 cannot be moved. To the second mold 17. Then, after the mold apparatus 15 is installed in an injection molding machine (not shown) and the molding material is injected into the molding space 19 of the mold apparatus 15 which is clamped, the molded product 10 is first opened by the mold opening of the second mold 17. In a state where the mold 16 is peeled off, the molded product 10 is projected to the first mold 16 side by the projecting pin 20 and is taken out from the second mold 17. The molded product 10 could not be taken out from the second mold 17 by the protruding pin 20 because it was sandwiched between the portions 18 and could not escape. Therefore, the center part of the molded product 10 was pulled with pliers, and the molded product 10 could be forcibly removed from the second mold 17. However, there is a disadvantage that the undercut portion 14 is damaged.

  The molded product 10 can be applied to the round shape shown in FIGS. 7 and 8 in addition to the square shape shown in FIGS. 5 and 6. In short, as the molded product 10, any structure having an undercut portion 14 between the outer wall portion 12 and the inner wall portion 13 is applicable.

JP 2013-237212 A

  The present invention has been made in view of the above-described background art, and an object of the present invention is to allow a molded product to be appropriately taken out with a protruding pin without damaging the undercut portion.

  The present invention is a mold apparatus for injection molding a molded article having an undercut portion between an outer wall portion and an inner wall portion, and includes a first die, a second die, a slide piece, and an elastic member. The first mold is provided with a molding recess that constitutes a part for molding the outer wall portion of the molded product as a recess from the split surface portion of the first mold to the inside of the first mold, and the second mold has an inner wall portion of the molded product. And a molding recess that constitutes a portion for molding the undercut portion and an annular piece receiving portion that surrounds the forming recess are provided as depressions from the split surface portion of the second mold to the inside of the second mold, and the slide piece is accommodated in the piece. The inner part of the slide piece and the molded product provided in the part corresponding to the molding recess of the second mold are configured in an annular shape that is movably accommodated in the first mold side and the second mold side. Undercut forming that forms the part that forms the undercut and the outer wall from the inner wall The undercut molding part is formed in an annular shape protruding from the slide piece to the inside of the inner hole part, and the elastic member is pushed in the direction of the first mold to the slide piece accommodated in the piece accommodation part. As the mold apparatus is clamped, the first mold pushes the slide piece into the piece housing portion against the elasticity of the elastic member, and the molding space is formed in the mold apparatus. The slide piece is made of an elastic member in accordance with the mold opening of the mold apparatus after the molding material is injected into the molding space while being composed of the molding recess of the first mold, the molding recess of the second mold, and the undercut molding portion of the slide piece. The undercut part and the inner wall part of the molded product protrude from the piece housing part to the first mold side due to the elasticity of the structure, and are separated from the molding recess of the second mold.

  According to the present invention, as the mold apparatus is clamped, the first mold pushes the slide piece into the piece accommodating portion against the elasticity of the elastic member, and the molding space is formed in the mold apparatus inside the mold apparatus. The slide piece is formed by the elasticity of the elastic member in accordance with the mold opening of the mold apparatus after the molding material is injected into the molding space part, while the concave piece, the second mold molding concave part and the undercut molding part of the slide piece are formed. By projecting from the housing part to the first mold side, the undercut part and the inner wall part of the molded product are peeled off from the molding concave part of the second mold, so that the inner wall part of the molded product shrinks inward, and to the inner side of the inner wall part. With the shrinkage, the undercut portion of the molded product is easily peeled from the undercut molding portion of the slide piece to the second mold side. For this reason, by projecting the molded product from the slide piece to the first mold side with the ejecting pin, the undercut portion of the molded product is flexed and peeled appropriately without being damaged from the undercut molded portion of the slide piece. It is possible to take out from the slide piece to the first mold side, and there is an effect that the molded product can be taken out appropriately with a protruding pin. Further, in the present invention, if the elastic member is disposed between the bottom portion of the piece accommodating portion and the bottom portion of the slide piece, the space between the piece accommodating portion and the slide piece can be utilized as an installation space for the elastic member.

Sectional drawing which shows the state of the mold opening of the type | mold apparatus which concerns on the form for inventing. Sectional drawing which shows the state of the mold clamping of the type | mold apparatus which concerns on the form for inventing. Sectional drawing which shows the state of the protrusion of the type | mold apparatus which concerns on the form for inventing. The side view which shows the injection molding machine using the type | mold apparatus which concerns on the form for inventing. The perspective view which shows the external appearance of the conventional molded article. FIG. 101 is a sectional view taken along line 101-101 in FIG. 5. The perspective view which shows the external appearance of another conventional molded article. FIG. 102 is a sectional view taken along line 102-102 in FIG. 7.

  With reference to FIG. 4, the structure of the injection molding machine 71 using the type | mold apparatus 1 which concerns on the form for inventing is demonstrated. The structure of the mold apparatus 1 will be described with reference to FIG. In FIG. 4, the injection molding machine 71 has a configuration in which a mold clamping device 72 and an injection device 73 are provided on a device housing 74, and a control device 75 is provided on the device housing 74.

  The mold clamping device 72 is configured to open and close the mold device 1, and includes a fixed plate portion 76, a movable plate portion 77, a tie bar portion 78, and an ejector portion 79. The injection device 73 is configured to plasticize and inject a molding material, and includes a hopper portion 80, an injection driving portion 81, and a nozzle portion 82. The control device 75 is configured to control various conditions such as injection speed and pressure of injection molding. The mold apparatus 1 includes a first mold 2, a second mold 3, and a slide piece 4.

  The operation of the injection molding machine 71 shown in FIG. 4 will be described. The mold apparatus 1 is installed in the injection molding machine 71 by attaching the first mold 2 to the fixed plate portion 76 and attaching the second mold 3 to the movable plate portion 77. Then, the movable plate portion 77 moves to the fixed plate portion 76 side from the mold opening state where the distance between the fixed plate portion 76 and the movable plate portion 77 is maximized as the mold clamping device 72 is clamped. The first mold 2 and the second mold 3 are in a mold-clamping state while taking the slide piece 4 into them.

  Next, after the nozzle portion 82 comes into contact with the fixed plate portion 76 and the plasticized molding material is injected from the injection driving portion 81 through the nozzle portion 82 into the molding space inside the mold apparatus 1, With the mold opening of the clamping device 72, the movable plate 77 moves away from the fixed plate 76 and the first mold 2 and the second mold 3 move the slide piece 4 toward the first mold 2 while moving the mold. In addition, the molded product is opened, and the molded product is discharged from the second mold 3 by the discharging operation of the ejector portion 79. The discharged molded product falls downward from between the first mold 2 and the second mold 3 and is taken out of the injection molding machine 71.

  The structure of the mold apparatus 1 will be described in detail with reference to FIG. In FIG. 3, the mold apparatus 1 includes a first mold 2, a second mold 3, a slide piece 4, an elastic member 5, and a support member 6. FIG. 3 exemplifies a mode in which the ejector pin 7 of the ejector portion is disposed in the pin hole portion 32 of the mold apparatus 1.

  The first mold 2 includes a molding concave portion 21, a molding convex portion 22, a cavity portion 23, and a gate portion 24. The molding recess 21 has a ring shape that is recessed from the split surface portion 25 of the first mold 2 into the first mold 2 and surrounds the molding convex portion 22 so as to constitute a part for molding the outer wall portion 12 of the molded product 10. . The molding convex portion 22 is provided in a configuration that protrudes from the bottom of the molding concave portion 21 toward the second mold side from the bottom surface of the molding concave portion 21 so as to constitute a portion for molding the central portion of the molded product 10. The cavity 23 is configured to be recessed from the surface of the molding convex portion 22 on the second mold 3 side into the molding convex portion 22. The gate portion 24 is configured to penetrate the cavity portion 23 of the first mold 2 and the surface portion 26 on the movable plate portion 77 side shown in FIG.

  In FIG. 3, the second mold 3 includes a molding concave portion 31, a pin hole portion 32, a piece accommodating portion 33, an elastic accommodating portion 34, a stopper portion 35, and a through hole portion 36. The molding recess 31 is formed in the second mold 3 as a recess from the split surface portion 37 of the second mold 3 to the inside of the second mold 3 so as to constitute a part for molding the inner wall portion 12 and the undercut portion 14 of the molded product 10. Provided. The pin hole portion 32 is configured to penetrate the bottom portion of the molding recess 31 and the surface portion 38 on the side of the movable plate portion 77 shown in FIG.

  Returning to FIG. 3, the piece accommodating portion 33 is an annular shape that surrounds the molding recess 31, and is recessed from the dividing surface portion 37 of the second mold 3 into the second mold 3. A plurality of elastic accommodating portions 34 are provided in the circumferential direction surrounding the molding concave portion 31, and are recessed from the bottom of the piece accommodating portion 33 toward the stopper portion 35. A plurality of stopper portions 35 are provided corresponding to the elastic accommodating portions 34, and are configured to be recessed from the surface portion 38 of the second mold 3 into the second mold 3.

  The stopper portion 35 is configured to be recessed from the surface portion 38 of the second mold 3 into the second mold 3. The through-hole portion 36 is provided in a portion between the elastic housing portion 34 and the stopper portion 35 of the second mold 3 and has a hole diameter smaller than the hole diameter of the elastic housing portion 34 and the hole diameter of the stopper portion 35. 34 is configured to penetrate through the bottom portion of 34 and the bottom portion of the stopper portion 35.

  The slide piece 4 is formed in an annular shape that is movably accommodated in the first mold 2 side and the second mold 3 side in the piece accommodating portion 33, and includes an inner hole portion 41, an undercut molding portion 42, and an elastic accommodating portion. 43, a support mounting portion 44 is provided. The inner hole portion 41 is provided in a portion corresponding to the molding concave portion 31 of the slide piece 4.

  The undercut molding part 42 is formed in an annular shape projecting from the slide piece 4 to the inner side of the inner hole part 41 so as to constitute a part for molding the undercut part 14 and the outer wall part 12 from the inner wall part 13 of the molded product 10. Composed.

  A plurality of elastic accommodating portions 43 are provided corresponding to the elastic accommodating portions 34 and are recessed from the surface portion 45 of the slide piece 4 on the second mold 3 side into the inside of the slide piece 4. A plurality of support attaching portions 44 are provided corresponding to the elastic accommodating portions 34 and are configured as screw hole portions in which female threads are formed on the inner wall surface portion of the hole recessed from the bottom portion of the elastic accommodating portion 43 to the inside of the slide piece 4. .

  The elastic member 5 is configured to give elasticity to the slide piece 4 in the direction of pushing out toward the first mold 2, and is not limited to an aspect made of a coil spring, but an aspect made of a coil spring is exemplified.

  The support member 6 has a configuration having an attachment portion 61 at one end and a stopper 62 at the other end, and is not limited to an embodiment made of a bolt with a hole, but an embodiment made of a bolt with a hole. Illustrated. As the attachment portion 61, a male screw portion is exemplified.

  The structure in which the slide piece 4 is assembled to the second mold 3 will be described. Both ends of the elastic member 5 arranged in the piece accommodation portion 33 are the elastic accommodation portion 34 of the second mold 3 and the elastic accommodation portion 43 of the slide piece 4. The mounting portion 61 of the support member 6 is fastened to the support mounting portion 44 from the stopper portion 35 of the second mold 3 via the through-hole portion 36 and the internal space of the elastic member 5.

  Since the support member 6 is attached to the slide piece 4 as described above, the slide piece 4 is pushed out to the first mold 2 side by the elasticity of the elastic member 5 as shown in FIG. The support member 6 of the slide piece 4 is prevented so that the stopper portion 62 collides with the through hole portion 36 side of the stopper portion 35 and the slide piece 4 does not protrude further from the piece accommodating portion 33 to the first mold 2 side. Protrusion from the second mold 3 to the first mold 2 side is restricted.

  The operation of the mold apparatus 1 will be described with reference to FIGS. As shown in FIG. 2, the first mold 2 is attached to the fixed plate portion 76, the second die 3 is attached to the movable plate portion 77, and the slide piece along with the mold clamping of the mold clamping device 72 shown in FIG. 4. 4 is pushed from the first mold 2 to the second mold 3 side to compress the elastic member 5 and is accommodated in the piece accommodating portion 33, and the stopper portion 62 of the support member 6 is elastic of the stopper portion 35 of the second mold 3. The separation surface 25 of the first mold 2 and the separation surface 37 of the second mold 3 come into contact with each other, and the first mold 2 of the first mold 2 and the first mold of the slide piece 4 are separated from the bottom portion on the side of the housing portion 34. 2 side surface portions 46 come into contact with each other, the first mold 2 and the second mold 3 are in a clamped state in which the slide piece 4 is taken into the interior, and the molding space portion 8 is configured inside the mold apparatus 1. The

  The molding space 8 includes the molding recess 21, the molding protrusion 22, the cavity 23, the molding recess 31, the undercut molding portion 42, and the ejection pin 7 shown in FIG. 3. Then, the plasticized molding material 9 is injected from the nozzle part 82 shown in FIG. 4 into the molding space part 8 via the gate part 24 shown in FIG. In FIG. 2, the illustration of the molding material 9 injected into the molding space 8 is omitted.

  Thereafter, as the second mold 3 moves away from the first mold 2 by the mold opening of the mold clamping device 72, the slide piece 4 is pushed out toward the first mold 2 while contacting the first mold 2 with the elastic member 5, As shown in FIG. 1, the stopper portion 62 of the support member 6 collides with the through hole portion 36 side of the stopper portion 35 of the second mold 3, and the movement of the slide piece 4 to the first mold 2 side is restricted. Is done. As described above, the portion on the first mold 2 side of the slide piece 4 is moved from the piece accommodating portion 33 of the second mold 3 to the first mold 2 side, thereby being molded in the molding space 8 (see FIG. 2). The molded product 10 is peeled off from the molding recess 31 and the ejection pin 7 of the second mold 3.

  That is, as shown in FIG. 1, as the mold apparatus 1 opens, the slide piece 4 protrudes from the piece accommodating portion 33 toward the first mold 2 due to the elasticity of the elastic member 5, and the inner wall portion 13 of the molded product 10. When the undercut portion 14 is peeled off from the molding recess 31 and the projecting pin 7 of the second mold 3, the inner wall portion 13 of the molded product 10 is shrunk inward. The undercut portion 14 is easily peeled from the undercut molding portion 42 of the slide piece 4 to the second mold 3 side. Thereafter, the mold opening of the mold clamping device proceeds, the slide piece 4 and the second mold 3 both move away from the first mold 2, and the molded product is between the first mold 2 and the slide piece 4. A drop space portion 11 is formed which is necessary for removing 10 from the undercut molding portion 42 of the slide piece 4. With the formation of the drop space 11, the mold opening of the mold clamping device stops.

  Thereafter, along with the ejecting operation of the ejector portion 79 in FIG. 4, the protruding pin 7 moves to the first mold 2 side as shown in FIG. 3, and the central portion inside the inner wall portion 13 of the molded product 10 is moved to the first portion. By projecting to the side of the first mold 2, the undercut portion 14, which has been easily peeled from the undercut molded portion 42 to the second mold side as the inner wall 13 of the molded product 10 shrinks, is bent and the slide piece 4. The undercut molding portion 42 is appropriately peeled off without being damaged, and the molded product 10 can be taken out from the slide piece 4 to the first mold 3 side, and the molded product 10 can be taken out properly with the protruding pin 7. . The molded product 10 projected by the projecting pin 7 falls downward from the drop space 11 between the first mold 2 and the second mold 3 and is taken out of the injection molding machine 71 of FIG.

  1 to 3 exemplify the mode of the mold apparatus 1 for injection-molding the square-shaped molded article 10 shown in FIGS. 5 and 6, the round-shaped molding shown in FIGS. 7 and 8 is described. The present invention can also be applied to the mold apparatus 1 for injection molding the product 10. The mode of the mold apparatus 1 for injection molding the round shaped molded article 10 shown in FIGS. 7 and 8 is the molding of the molding concave portion 21 and the molding convex portion 22 of the first mold 2 shown in FIG. The modeling of the molding recess 31 of 3 is changed to a modeling that matches the central part of the molded product 10 shown in FIG. Further, the protruding pin 7 is not limited to a single one, and a plurality of protruding pins 7 can be applied.

DESCRIPTION OF SYMBOLS 1 is a type | mold apparatus, 2 is 1st type | mold, 3 is 2nd type | mold, 4 is a slide piece, 5 is an elastic member, 6 is a supporting member, 7 is a protrusion pin, 8 is a molding space part, 9 is molding material, 10 is Molded product, 11 is a falling space, 12 is an outer wall, 13 is an inner wall, 14 is an undercut, 15 is a mold device, 16 is a first mold 27 is a second mold, 18 is an undercut molding, 19 is Molding space part, 20 is a protruding pin, 21 is a molding concave part, 22 is a molding convex part, 23 is a cavity part, 24 is a gate part, 25 is a divided surface part, 26 is a surface part, 27 to 30 are missing numbers, 31 is a molding concave part, 32 is a pin hole part, 33 is a piece accommodating part, 34 is an elastic accommodating part, 35 is a stopper part, 36 is a through-hole part, 37 is a divided surface part, 38 is a surface part, 39; 40 is a missing number, 41 is an inner hole part, 42 is an undercut molding part, 43 is an elastic accommodating part, 44 is a support attachment part, 45; , 47 to 60 are missing numbers, 61 is a mounting portion, 62 is a stopper portion, 63 to 70 are missing numbers, 71 is an injection molding machine, 72 is a clamping device, 73 is an injection device, 74 is a device housing, and 75 is a control device. , 76 is a fixed plate portion, 77 is a movable plate portion, 78 is a tie bar portion, 79 is an ejector portion, 80 is a hopper portion, 81 is an injection drive portion, and 82 is a nozzle portion.

Claims (2)

  A mold apparatus comprising a first mold, a second mold, a slide piece, and an elastic member for injection-molding a molded product having an undercut portion between an outer wall portion and an inner wall portion. A molding recess that constitutes a part for molding the outer wall portion of the product is provided as a recess from the dividing surface portion of the first mold to the inside of the first mold, and the inner wall portion and the undercut portion of the molded product are molded in the second mold. A molding concave portion constituting the portion and an annular piece housing portion surrounding the molding concave portion are provided as depressions from the split surface portion of the second mold to the inside of the second mold, and the slide piece is provided on the piece housing portion on the side of the first mold. And the second mold side are movably accommodated, and the slide piece has an inner hole portion provided in a portion corresponding to the molding recess of the second die and an undercut portion from the inner wall portion of the molded product. And an undercut molding part that constitutes a part for molding the outer wall part. -The cut molding part is configured in an annular shape protruding from the slide piece to the inside of the internal hole part, and the elastic member is configured to give elasticity in the direction of pushing out to the first mold side to the slide piece accommodated in the piece accommodation part. In addition, as the first-type split surface portion and the second-type split surface portion are clamped so as to come into contact with each other, the first-type split surface portion makes the surface portion of the slide piece on the first-type side elastic. The molding space is formed in the mold apparatus from the molding recess of the first mold, the molding recess of the second mold, and the undercut molding part of the slide piece. On the other hand, after the molding material is injected into the molding space, the slide piece is moved by the elasticity of the elastic member as the first mold dividing surface part and the second mold dividing surface part are opened so as to be separated from each other. Projects from the frame housing part to the first mold side Te, mold apparatus for injection molding, characterized in that became configuration undercut portions and the inner wall portion of the molded article is peeled from the molding recess of the second mold.   2. The mold apparatus for injection molding according to claim 1, wherein the elastic member is disposed between the bottom portion of the piece receiving portion and the bottom portion of the slide piece.

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