JP4812033B2 - Method for molding composite molded article and molding die - Google Patents

Description

  The present invention relates to a molding method and a molding die for a composite molded product, in which a molded product is obtained by primary and secondary molding using a stationary die and a slide die, and more specifically, A recess and a core are formed at a predetermined interval on the parting surface side of one mold of the slide mold, and the recess and core of the one mold are formed on the parting surface side of the other mold. Correspondingly, using a mold in which a core and a recess are formed at a predetermined interval, the slide mold is driven to the primary molding position, and a pair of semi-molded products are subjected to primary injection molding. The present invention relates to a molding method for obtaining a composite molded product from secondary molding in which a pair of semi-molded products are joined by driving to a secondary molding position, and a molding die used for carrying out this method.

  A manufacturing method using an injection molding machine is known as a method for manufacturing a hollow molded product made of a synthetic resin. When a hollow molded product is manufactured by this injection molding machine, the hollow molded product is formed as a half-hollow molded product or a divided body in the primary molding, the divided surfaces are butted and butted in the secondary molding. One hollow molded product is manufactured by injecting molten resin into the part.

Patent No. 3047213 Japanese Patent No. 3326752 JP-A-62-87315

  Various molds used for carrying out this injection molding method have been proposed in the past, and many proposals have been proposed by the present applicant in Patent Documents 1 to 3, etc., but generally shown schematically in FIG. Thus, it is comprised from the substantially movable metal mold | die 50 and the slide metal mold | die 60. FIG. A concave 51 for molding one semi-hollow molded product is provided on the parting surface side of the movable mold 50, and a core 52 for molding the other semi-hollow molded product is provided at a predetermined position below it. It has been. On the parting surface P ′ side of the slide mold 60, a core 61 is provided corresponding to the recess 51, and a recess 62 is provided corresponding to the core 52. Accordingly, when the slide mold 60 is set to the first position shown in FIG. 4A and the movable mold 50 is clamped with respect to the slide mold 60, the slide 51 and the recess 51 of the movable mold 50 slide. A cavity for molding one half-hollow molded product is formed by the core 61 of the mold 60, and the other half-hollow molded product is molded by the core 52 of the movable mold 50 and the recess 62 of the slide mold 60. A cavity is configured for. When these cavities are injected and filled with molten resin from the sprue, as is conventionally known, a pair of semi-hollow molded products A 'and B' are primarily molded so as to have joint space portions a and b around them.

  After solidification, the one half-hollow molded product A ′ is left on the movable mold 50 and the other half-hollow molded product B ′ is left on the slide mold 60 to open the movable mold 50. Then, when the slide mold 60 is slid to the secondary molding position shown in FIG. 4A by the piston cylinder unit 64, the pair of semi-hollow molded products A ′ and B ′ are joined together. Matching occurs in the parts a and b. When the movable mold 50 is clamped at this position, the pair of semi-hollow molded products A ′ and B ′ are brought into contact with each other to form the joining space portions a and b. Therefore, when the molten resin is injected from the spru 66 through the gate to the joining space portions a and b and subjected to secondary molding, the pair of semi-hollow molded products A ′ and B ′ are joined at the joining space portions a and b, Molded. When the movable mold 50 is opened, the ejector pin protrudes and a hollow molded product is obtained.

As described above, when a movable mold and a slide mold are used, a pair of semi-hollow molded products are formed by primary injection molding, and after waiting for cooling and solidification, the movable mold is opened and the slide mold is slid. When driven to align a pair of semi-hollow molded products, and then clamped and joined with a pair of semi-hollow molded products by secondary injection molding, a hollow molded product can be obtained, so each process can be automated and hollow molded There is an advantage that the product can be mass-produced. Moreover, since the primary injection molding for molding a pair of semi-hollow molded products and the secondary injection molding for joining a pair of semi-hollow molded products are also performed in the mold, a hollow molded product having a complicated shape can be manufactured. It also has features. However, there is a drawback that the mold becomes large or complicated. The reason will be described below. When the mold is clamped at the secondary molding position shown in FIG. 4A, the core 61 of the slide mold 60 exceeds the parting surface P of the movable mold 50. In order to avoid this, the core 61 of the slide mold 60 is provided so as to be positioned above the upper end surface of the movable mold 50 during the secondary molding. That is, the slide mold 60 is large regardless of the size of the other semi-hollow molded product B ′. Further, the core 52 of the movable mold 50 cannot be clamped because the slide mold 60 gets in the way. Therefore, the slide mold 60 has a pocket PK in which the core 52 of the movable mold 50 is retracted, and the slide mold 60 is complicated. Instead of providing the pocket PK, the position of the core 52 can be shifted downward from the lower end of the slide mold 60. However, when the position is shifted, the mold becomes larger. As the mold becomes larger, the molding machine to which the mold is attached becomes larger.
This is because a fixed mold and a movable mold that is opened and closed with respect to the fixed mold and is slidably driven are combined molded products such as two-color molded products and laminated products. The same can be said for injection molding.

  Therefore, the present invention uses a small fixed mold and a small movable mold or slide mold, and is a composite of a hollow molded product, a two-color molded product, a laminated molded product, etc. composed of two semi-molded products. It aims at providing the shaping | molding die used for implementation of the shaping | molding method of the composite molded product which can shape | mold a molded product, and this method.

  In order to achieve the above object, the present invention comprises primary injection molding and secondary molding. At this time, a mold having a step is used instead of a mold having the same parting surface. This step is larger than the highest core height. Thereby, even if it clamps in a secondary molding position, the core of one metal mold | die does not contact the parting surface of the other metal mold | die. According to the present invention, since a mold having a stepped parting surface is used, the thickness of the mold is different between the primary molding position and the secondary molding position. Accordingly, the present invention is configured such that the mold thickness adjustment and the mold clamping force adjustment are performed each time. Alternatively, it is configured in advance to perform primary and secondary molding with a clamping force.

  Thus, in order to achieve the above object, the invention described in claim 1 is formed on the parting surface side of one of the fixed mold and the slide mold at a predetermined interval. Primary molding in which the concave portion and the core, and the core and the concave portion formed on the parting surface side of the other die at a predetermined interval corresponding to the concave portion and the core of the one die are aligned. The primary mold is clamped at the position, and the slide mold is formed with the primary injection molding for forming the paired semi-molded product and the half-molded product molded by the primary injection molding remaining in the respective molds. The mold is driven to the secondary molding position where the paired semi-molded product is aligned, the secondary mold is clamped, and the secondary molding is performed by integrating the required portions of the paired semi-molded product. When obtaining, the parting surface constituting the recess used at this time; Between the parting surface constituting the serial core arranged so that there is a height or more steps of the core higher of the core. According to a second aspect of the present invention, in the molding method according to the first aspect, the mold thickness and the clamping force during the secondary molding are adjusted before the secondary mold clamping after the primary injection molding. Adjust the mold thickness and clamping force at the time of primary injection molding after molding until the primary mold clamping of the next shot, and perform the first and second molding alternately with this adjusted clamping force. In the molding method according to claim 1, the mold clamping force in the primary molding position and the mold clamping force in the secondary molding position are set in advance in the molding method according to claim 1, and the set mold is set. The first and second moldings are alternately performed by the tightening force.

  The invention described in claim 4 includes a fixed mold and a slide mold, and a recess for molding a pair of semi-molded products is formed on the parting surface side of one of these molds. The core is formed at a predetermined interval, and the core and the recess corresponding to the recess and the core are formed at a predetermined interval on the parting surface side of the other mold, and the slide mold Is a primary molding position where the concave portion and the core of the one mold are respectively aligned with the core and the concave portion of the other mold, the concave portion of the one mold, and the concave portion of the other mold. Between the parting surface forming the recess and the parting surface forming the core is the higher of the cores. The structure according to claim 5, wherein the step is configured so as to have a level difference greater than the height of the core Ming, the mold according to claim 4, as mold clamping force corresponding to the thickness of the mold is provided with a settable clamping device in primary and secondary molding position configured.

  As described above, according to the present invention, when a composite molded product is obtained by primary and secondary molding using a fixed mold and a slide mold, the mold used at this time has a recess. Since a mold with a step more than the height of the higher core among the cores is used between the parting surface and the parting surfaces that make up the core, clamping is performed at the secondary molding position. When doing so, the core formed on one mold does not interfere with the parting surface of the other mold. Therefore, it is not necessary to enlarge the mold in order to avoid interference, and it is not necessary to provide a pocket for retracting the core, and the mold does not become complicated. According to another invention, the mold clamping force at the primary molding position and the mold clamping force at the secondary molding position are set in advance, and the first and second moldings are alternately performed with the set mold clamping force. Therefore, it is not necessary to adjust the mold thickness during the first and second molding, and the injection process is not particularly complicated even though there is a step between the parting surfaces.

  Embodiments of the present invention will be described below. FIG. 1 is a cross-sectional view schematically showing the entire mold with the slide mold open. As shown in FIG. 1, the mold according to the present embodiment is also a fixed mold 10. And a moving mold, that is, a slide mold 30. And the parting surface of the metal mold | die which concerns on this Embodiment has a level | step difference instead of the same surface. That is, there is a step D between the first and second parting surfaces P1 and P2 of the fixed mold 10, and between the first and second parting surfaces P′1 and P′2 of the slide mold 30. Has a step D. This will be described in more detail below.

  The mold according to the present embodiment includes a fixed mold 10 attached to a stationary platen 1 fixedly provided on a gantry and a movable platen 20 provided on the gantry so as to be movable in the mold opening / closing direction. It consists of a slide mold 30 attached. The parting surface of the fixed mold 10, in other words, the surface in contact with the parting surface of the slide mold 30 when the mold is clamped, is from two levels of the first parting surface P1 and the second parting surface P2. Therefore, the step D is larger than the height of the higher core described later. On the first parting surface P1 having such a step D, a fixed recess 11 for forming one semi-hollow molded product is formed. Moreover, the fixed side core 12 for shape | molding the other semi-hollow molded product which protruded from the 2nd parting surface P2 is provided in the downward position. The fixed core 12 is lower than the first parting surface P1. A small core 13 for forming a bonding space is provided around the fixed core 12.

  The fixed mold 10 is provided with a primary molding sprue 14. The primary forming sprue 14 is opened through a gate at the bottom wall of the fixed recess 11 and the vicinity of the fixed small core 13. Similarly, in the vicinity of the first parting surface P1 on the peripheral wall of the fixed-side concave portion 11, a sprue 15 for secondary molding is opened through a gate. On the other hand, an injection nozzle 3 of a conventionally known injection unit 2 faces the fixed platen 1. Although not shown in FIG. 1, the fixed mold 10 is provided with a sprue or runner switching device, and the molten resin injected from the injection nozzle 3 is transferred to the spurs for primary and secondary molding 14, 15. It is possible to switch to as appropriate.

  The slide mold 30 is provided on the movable platen 20 so as to be slidable in the vertical direction. A piston cylinder unit 21 is provided to drive the slide mold 30 to the primary molding position shown in FIG. 1 and the upper secondary molding position. The piston cylinder unit 21 is attached to an arm 23 extending in the horizontal direction from a support column 22 provided on the top of the movable platen 20, and a lower end portion of the rod 24 is connected to the upper surface of the slide mold 30. . The parting surface of the slide mold 30 also includes first and second parting surfaces P′1 and P′2, and the step D is the same as the step D between the parting surfaces P1 and P2 of the fixed mold 10. It has become. On the first parting surface P′1 of the slide mold 30 configured as described above, a slide-side core 31 protruding from the surface P′1 and corresponding to the fixed-side recess 11 of the fixed mold 10 is provided. Is provided. The slide side core 31 is smaller than the fixed side recess 11 by a predetermined amount, and a slide side small core 33 is provided around the slide side core 31. A slide-side recess 32 corresponding to the fixed-side core 12 is formed in the first parting surface P ′ at the lower position. The slide-side recess 32 is larger than the fixed-side core 12 by a predetermined amount.

  Although not shown in FIG. 1, the mold clamping device is also provided in this embodiment. According to the present embodiment, there is a gap between the first and second parting surfaces P1 and P2 of the fixed mold 10 and between the first and second parting surfaces P′1 and P′2 of the slide mold 30. Since the step D is provided, the mold thickness varies between the primary injection molding and the secondary molding in which the slide mold 30 is moved. Therefore, when the toggle type mold clamping device is applied, the mold thickness adjustment and the mold clamping force are adjusted before the primary injection molding, and the primary mold clamping force is obtained. Further, after the primary injection molding, the mold thickness adjustment and the mold clamping force are adjusted until the mold clamping force is loosened and the secondary mold is closed, so that the secondary mold clamping force is obtained. Such an adjustment can be automatically adjusted, for example, as disclosed in Japanese Patent No. 3747425. Further, instead of adjusting each time, the adjusted primary and secondary mold clamping forces can be set, and the set mold clamping force can be called to perform primary and secondary molding. When the direct pressure type mold clamping device is applied, the step can be absorbed by the stroke of the rod of the hydraulic piston cylinder unit, so that there is an advantage that the mold thickness adjustment is not particularly required.

  Next, a molding example using the mold will be described. The primary mold is clamped at the primary injection molding position shown in FIG. That is, the movable platen 20 is clamped with respect to the fixed platen 1. Then, as shown in FIG. 2A, the first parting surface P <b> 1 and the second parting surface 11 are formed by the fixed side recess 11 of the fixed mold 10 and the slide side core 31 of the slide mold 30. The parting surface P′2 is mold-matched to form a first cavity C1 for molding one semi-hollow molded product. At the same time, the second cavity C2 for forming the other semi-hollow molded product is constituted by the fixed core 12 of the fixed mold 10 and the slide-side recess 32 of the slide mold 30. Molten resin is injected from the sprue 14 for primary molding. Thereby, a pair of semi-hollow molded products A1 and A2 are obtained. FIG. 2A shows a state in which the first and second cavities C1 and C2 are configured in this way and a pair of semi-hollow molded products A1 and A2 are formed.

  Waiting for cooling and solidification, the slide mold 30 is opened as shown in FIG. At this time, one half-hollow molded product A1 is opened so as to remain toward the stationary mold 10 and the other half-hollow molded product A2 remains toward the slide mold 30. At this time, the joining half-space portions a1 and a2 are formed in the openings of the pair of semi-hollow molded products A1 and A2.

  The slide mold 30 is slidably driven to the upper secondary molding position. At this secondary molding position, as shown in FIG. 3A, the pair of semi-hollow molded products A1 and A2 are aligned. Tighten the secondary mold. Then, the first parting surface P1 of the fixed mold 10 and the first parting surface P′1 of the slide mold 30 are matched with each other. The pair of semi-hollow molded products A1 and A2 are abutted at the opening. A space for bonding is formed by the half space portions a1 and a2 on the outer peripheral portion of the periphery. At this time, there is a step D between the first parting surface P 1 and the second parting surface P 2, and this step D is larger than the slide side core 31. There is no contact with the first parting surface P1. According to the present embodiment, since the fixed side core 12 has the same height, the fixed side core 12 does not come into contact with the second parting surface P ′ 2 of the slide mold 30.

  Molten resin is injected from the secondary molding sprue 15 into the joining space. Thus, the pair of semi-hollow molded products A1 and A2 are integrated. When the slide mold 30 is opened after waiting for cooling and solidification, an ejector pin (not shown) protrudes and the hollow molded product S protrudes. The protruding state is shown in FIG.

  In the above embodiment, the pair of semi-hollow molded products A1 and A2 have a symmetrical shape having a substantially bowl shape, but it is obvious that one of them can be similarly implemented with a flat lid. Furthermore, it is clear that a molded product in the form of a laminate of thick semi-molded products can be molded in the same manner. In addition, a plurality of molded products can be simultaneously molded from two or more pairs of semi-molded products. According to the present embodiment, the entire circumference of the semi-hollow molded product is joined at the time of secondary molding, but a molded product obtained by joining only required portions can also be obtained. For secondary molding, instead of injecting molten resin, for example, as shown in Japanese Patent No. 2729900, the joint can be heated and pressure welded. It is clear that the same effect can be obtained even if implemented in this way.

It is sectional drawing expanded and shown in the state which opened the metal mold | die which concerns on embodiment of this invention. It is a figure which shows the shaping | molding step using the metal mold | die which concerns on embodiment of this invention, The (a) is the state after primary injection molding, The (i) is a slide mold after primary injection molding is finished. It is sectional drawing which shows an open state, respectively. It is a figure which shows the shaping | molding step using the metal mold | die which concerns on embodiment of this invention, The (a) shows the state after secondary shaping | molding, The (a) shows the state which takes out the molded article, respectively. It is sectional drawing. It is sectional drawing which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fixed mold 11 Fixed side recessed part 12 Fixed side core 30 Slide mold 31 Slide side core 32 Slide side recessed part P1, P2 The 1st, 2nd parting surfaces of a fixed mold P'1, P'2 First and second parting surfaces D Step between first and second parting surfaces

Claims (5)

A concave mold and a core formed at a predetermined interval on the parting surface side of one of the fixed mold and slide mold, and the one mold on the parting surface side of the other mold A primary mold clamping is performed at a primary molding position where a core and a recess formed at a predetermined interval corresponding to a recess and a core of the mold are aligned with each other, thereby forming a pair of semi-molded products 1 Next injection molding,
With the semi-molded product formed by the primary injection molding remaining in each mold, the slide mold is driven to the secondary molding position where the paired semi-molded products are aligned, and the secondary mold clamping is performed. And when obtaining the molded product from the secondary molding that integrates the required parts of the paired semi-molded product,
Between the parting surface constituting the concave portion used at this time and the parting surface constituting the core, there is a step more than the height of the higher core of the cores. A method of forming a composite molded product characterized by the above. 2. The molding method according to claim 1, wherein a mold thickness and a clamping force at the time of secondary molding are adjusted between primary injection molding and secondary mold clamping, and the primary mold of the next shot after secondary molding. Molding of a composite molded product characterized by adjusting the mold thickness and clamping force at the time of primary injection molding until clamping and alternately performing primary and secondary molding with the adjusted clamping force Method. The molding method according to claim 1, wherein a mold clamping force at a primary molding position and a mold clamping force at a secondary molding position are set in advance, and primary and secondary molding are alternately performed by the set mold clamping force. A method for forming a composite molded product, characterized in that it is carried out. The mold consists of a fixed mold and a slide mold. On the parting surface side of one of these molds, a recess and a core for forming a pair of semi-molded products are spaced at a predetermined interval. Formed on the parting surface side of the other mold, the core and the recess respectively corresponding to the recess and the core are formed at a predetermined interval,
The slide mold includes a primary molding position where a concave portion and a core of the one mold are respectively aligned with a core and a concave portion of the other mold, a concave portion of the one mold, and the other mold. It can be slidably driven to the secondary molding position where the concave portion of the mold is aligned,
A composite having a step between the parting surface forming the recess and the parting surface forming the core that is higher than the height of the higher core of the cores Mold for molding molded products. 5. The mold according to claim 4, further comprising a mold clamping device capable of setting a mold clamping force corresponding to the thickness of the mold at the first and second molding positions. Mold.

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