JP2005193634A - Injection-molded product manufacturing method and mold assembly therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold assembly of an injection-molded product capable of ensuring filling properties even in a part separated from the circumference in a thin-walled molded product. <P>SOLUTION: The mold assembly is equipped with a fixed mold 11 and a movable mold 12 mutually opened and closed to form a product cavity 13 at the time of mold clamping and the gate 20 provided on the fixed mold 11 to communicate with a material passage 19 and used for manufacturing the injection-molded product 1 equipped with a plurality of thin-walled members 2 arranged so as to leave an interval, the intermediate frame part 3 formed between the thin-walled members 2 and 2, and the peripheral frame part 4 provided around a plurality of the thin-walled members 2 and 2. After the filling of the intermediate frame part 3 with a resin from the gate 20 is started, the peripheral frame part 4 is filled with the resin J from another gate 20A. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention provides an injection-molded body including a plurality of thin members arranged at intervals, an intermediate frame portion formed between the thin members, and a peripheral frame portion provided around the thin members. The present invention relates to a mold apparatus to be manufactured and a manufacturing method.

  For example, a battery accommodated in a mobile phone is accommodated in a battery case. This battery case has a substantially box-shaped thin wall portion and wall portions formed on the four sides of the periphery of the flat surface portion. Used in combination.

  And in this kind of thing, if the plane part becomes thick, the thickness of the cellular phone also becomes thick. Therefore, in order to avoid this, it is necessary to form the plane part by a thin member.

  Therefore, conventionally, when a plastic product having a thin part is manufactured by injection molding, a mold apparatus for forming a product cavity corresponding to a molded part having a desired thin part between molds that can be opened and closed with each other is provided. When the mold is closed, the product cavity is filled with a molten resin, and after cooling and solidifying, the mold is opened and released. However, in the case of a plastic product having a thin wall portion, the gap between the corresponding product cavities is also natural. Since the thin film is formed, there is a problem that it is difficult to fill the resin. Further, in the filling process in which the resin is filled, not only a gas such as air exists in the product cavity, but also a gas caused by the molten resin is generated. The gas generated from the molten resin and the air in the product cavity before filling are compressed by the molten resin and cause filling failure. There is.

  Therefore, the gate position or the degassing groove is devised to improve the wraparound property of the resin into the product cavity corresponding to the thin portion, but still 0.4 mm or less, for example, about 0.25 mm. Actually, it is difficult to form a thin portion. In addition, when a molded body having this type of thin-walled portion is manufactured by injection molding, a mold release step is performed after cooling and solidifying the molten resin. This mold release is usually provided so as to be able to advance and retract toward the product cavity. Extrusion is performed by an extruding pin or the like, and the thin portion usually occupies a large area, and thus the extruding pin may be located here. If it does so, there also exists a problem that the pressed part will deform | transform in the thin part about 0.25 mm.

  Therefore, in a manufacturing method of a molded body that manufactures a molded body having a thin portion using a plurality of mold bodies that are openable and closable and that form a product cavity between the molds when the mold is closed, a thin member is disposed between the molded bodies. A manufacturing method in which a rear mold is closed, a resin is injected into the product cavity to manufacture a molded body, and the thin member is a resin film (for example, Patent Document 1 and Patent Document 2) having a fusion property with the injection resin. Proposed.

  In the manufacturing method of the above-described prior art, the thin portion is formed by a separate thin member, and it is not necessary to form the thin portion by injection molding. In addition, when the molten resin is injected, the resin film, which is a thin-walled member, is softened or melted by the heat of the molten resin and integrated with the molten resin, so the thin-walled portion where the boundary between the thin-walled member and the injected resin is naturally integrated An injection molded body having the same can be obtained.

The thin injection molded body includes a plurality of thin members arranged at intervals, an intermediate frame portion formed between the thin members, and a peripheral frame portion provided around the thin members. In order to mold such a molded body, a plurality of gates are provided corresponding to the surrounding frame portion, and molten resin is filled into the product cavity from the gates. To do.
JP 2002-307477 A JP 2003-127172 A Japanese Patent Application No. 2003-402156

  In the injection molded body, since the molten resin filled from the gate passes through the surrounding frame portion and fills the intermediate frame portion, if the frame portion becomes thin, there is a risk of causing poor filling of the resin to the intermediate frame portion. is there.

  The present invention is intended to solve such a problem, and in a thin molded body, a mold apparatus for an injection molded body and a method for manufacturing the same that can ensure a filling property even in a portion away from the periphery. The purpose is to provide.

  According to a first aspect of the present invention, there is provided a plurality of molds that open and close to each other to form a product cavity between the molds, and a plurality of mold bodies that are provided in the mold body that forms the product cavity among the mold bodies and communicate with a material passage. A plurality of thin members disposed at intervals using a mold apparatus having a gate, an intermediate frame portion formed between the thin members, and a peripheral frame portion provided around the thin members In the manufacturing method of manufacturing an injection molded body comprising: a plurality of thin members arranged at intervals in the product cavity, the mold body is closed, and resin filling from the gate to the intermediate frame portion is performed After starting the process, the peripheral frame portion is filled with resin from another gate.

  The manufacturing method of claim 2 is a manufacturing method in which the intermediate frame portion is filled with a resin from a gate having a substantially linear cross section.

  The manufacturing method of claim 3 is a manufacturing method in which the thin member is a foam metal.

  5. The mold apparatus according to claim 4, wherein a plurality of mold bodies that open and close each other and form a product cavity therebetween when the mold is closed, and a gate that is provided in the mold body that forms the product cavity among these mold bodies and communicates with the material passage. A plurality of thin-walled members arranged at intervals, an intermediate frame formed between the thin-walled members, and an injection molded body including a peripheral frame provided around the thin-walled members. In the mold apparatus to be manufactured, the peripheral frame gate is disposed corresponding to the peripheral frame portion, the intermediate gate is disposed corresponding to the intermediate frame portion, and the resin filling start time of the peripheral frame gate and the intermediate gate is set. Is to control.

  According to another aspect of the mold apparatus of the present invention, the other mold body is provided with an advance / retreat pin that advances / retreats in the product cavity corresponding to the intermediate gate.

  According to a sixth aspect of the present invention, there is provided a mold apparatus in which the intermediate gate has a substantially linear cross section.

  The mold apparatus according to claim 7 fills the product cavity with resin from the material passage from the intermediate gate, and opens the mold body to open the resin in the intermediate gate and the resin in the product cavity. Is to separate

  The mold apparatus according to claim 8 is such that the advance / retreat pin advances / retreats to the tip of the gate.

  In the mold apparatus according to a ninth aspect, the thin member is a foam metal.

  According to the configuration of claim 1, when a plurality of molds are closed to form a product cavity between the mold cavities, and the resin is filled into the product cavity from the gate, the resin is filled into the intermediate frame portion first. The resin is satisfactorily filled in the intermediate frame located on the center side by delaying the resin filling to the surrounding peripheral frame.

  According to the second aspect of the present invention, since the cross section of the gate is formed in a linear shape, the resin can be more satisfactorily filled.

  According to the configuration of claim 3, when the resin is injected into the product cavity, the resin enters the pores of the foam metal, and the molded body in which the frame portion made of the resin and the foam metal forming the thin member is integrated. can get.

  According to the configuration of the fourth aspect, since the control means for controlling the resin filling start time between the peripheral frame gate and the intermediate gate is provided, the resin filling to the intermediate frame portion which is difficult to fill the resin is performed first, By starting the resin filling into the peripheral frame portion with a delay, the injection molded body provided with the intermediate frame portion can be molded well.

  According to the configuration of claim 5, after filling the resin, the advance / retreat pin is moved into the product cavity, so that the resin in the gate and the resin in the product cavity are well separated when the mold is opened. Can do.

  According to the sixth aspect of the present invention, since the cross section of the gate is formed in a linear shape, the resin can be more satisfactorily filled.

  According to the seventh aspect of the present invention, when the mold body is opened, the resin is cut off at the gate, and a molded body consisting of a frame portion formed by solidifying the resin and a thin member remains in the product cavity. Is taken out to obtain a molded body.

  According to the configuration of claim 8, after the resin is filled in the intermediate frame portion, the resin in the gate and the resin in the product cavity are separated by moving to the gate by the advance / retreat pin, and the resin is placed in the intermediate frame portion. A well-filled injection molded body is obtained. Further, since the gate is blocked by the advance / retreat pin, the diameter of the gate can be increased as compared with the case where the resin is cut after curing, and the resin can be filled smoothly.

  According to the ninth aspect of the present invention, when the resin is injected into the product cavity, the resin enters the pores of the foam metal, and the molded body in which the frame portion made of the resin and the foam metal forming the thin member are integrated. can get.

  Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below do not limit the contents of the present invention described in the claims. In addition, all of the configurations described below are not necessarily essential requirements of the present invention. In each example, by adopting an injection molded body having a novel thin wall portion different from the conventional one, a manufacturing method thereof and a mold apparatus, an unprecedented manufacturing method of an injection molded body and its mold apparatus are obtained, The method for manufacturing the injection molded body and the mold apparatus will be described respectively.

  Embodiment 1 of the present invention will be described below with reference to the accompanying drawings. 1 to 4 show Example 1 of the present invention, in which FIG. 1 shows an example of an injection-molded body having a thin portion that can be manufactured by the method of the present invention. In FIG. The molded body 1 constituting a part of the box body includes a plurality of thin-walled members 2, 2... Arranged at intervals, an intermediate frame portion 3 formed between the thin-walled members 2, 2. The peripheral frame part 4 provided in the circumference | surroundings of several thin member 2,2, ... is provided. As shown in FIG. 1, the thickness dimension W1 of the thin member 2 is 0.40 mm or less, 0.20 mm or more, and specifically about 0.25 mm. Since the thickness dimension W1 can be up to 0.10 mm, the lower limit can be 0.10 mm or more.

  As for the said surrounding frame part 4, the molded object 1 is equipped with the longitudinal edge parts 4A and 4A of a longitudinal direction, and the width direction edges 4B and 4B located in the length direction both sides.

  The molded body 1 has a rectangular shape that is long in the left-right direction as a whole, and the thin-walled member 2 has a rectangular shape that is long in the front-rear direction.

  The thin member 2 is made of a substantially flat foam metal 5. An example of the method for producing the foam metal 5 will be described. A metal powder, a water-soluble binder, a surfactant and water are mixed, and a water-insoluble organic solvent is further added to uniformly disperse and process the mixture into a flat plate shape. To form a molded body. As the surfactant, generally a detergent may be used, and a commercially available neutral detergent for kitchens such as a 28% mixed aqueous solution of alkyl glucoside and polyoxyethylene alkyl ether can be used. In addition, as the water-insoluble organic solvent, a water-insoluble carbon-based organic solvent having 5 to 8 carbon atoms such as neopentane, isohexane, heptane, isoheptane, benzene, octane, and toluene can be used. Moreover, since the metal powder constitutes a sintered porous metal body, it may be composed of a metal material applied to a metal porous body including a conventional porous metal sintered body, When the average particle size is less than 0.5 μm, it becomes difficult to increase the porosity of the sintered body. On the other hand, when the average particle diameter exceeds 500 μm, the dispersibility in the mixed raw material is lowered, and it becomes difficult to produce a homogeneous sintered body. Therefore, the average particle diameter is 0.5 to 500 μm, desirably 5 to 100 μm. The molded metal formed as described above is heated to foam the water-insoluble organic solvent to form the foam metal. Further, as another embodiment, a metal powder, a water-soluble binder, a surfactant, and water are mixed, and further a water-insoluble organic solvent is added to form a uniformly dispersed mixture into a flat plate shape, By heating this, the water-insoluble organic solvent may be foamed to form a foam metal.

  In FIG. 2, 11 is a fixed mold as a first mold body, 12 is a movable mold as a second mold body, and these fixed mold 11 and movable mold 12 are in the vertical direction (mold opening / closing direction) in FIG. It moves and opens and closes to form a product cavity 13 having a product shape between the molds when the mold is closed.

  The fixed mold 11 includes a fixed side mold plate 16 forming a product cavity 13 and a fixed side mounting plate (not shown). The fixed side mounting plate is a fixed side platen (see FIG. (Not shown), and a manifold (not shown) is provided between the fixed side mounting plate and the fixed side mold position. And the nozzle of the heating cylinder device which is a molding material supply device of an injection molding machine was connected to the fixed side mounting plate, and the resin was kept in a molten state in the runner in the manifold as injected from this nozzle. It is sent to a valve device to be described later. The manifold has a plurality of runners.

  The valve devices 17 and 17A provided in the fixed mold 11 have a material passage 19 inside the valve casing 18, and gates 20 and 20A communicating with the material passage 19 are provided at the tip of the valve casing 18, and A valve pin 21 as a valve body is provided in the valve casing 18 so as to be movable back and forth, and a fluid pressure cylinder device 22 for driving the valve pin 21 in the mold opening / closing direction is provided in the fixed die 11, and the valve pin is formed by the fluid pressure cylinder device 22 The tip closing portion 23 of 21 is fitted to the gates 20 and 20A to close the gate 20. Further, the upstream side of the material passage 19 is connected to the runner of the manifold, and a heating means (not shown) for heating the resin J in the material passage 19 to a molten state is provided on the outer periphery of the valve casing 18. .

  As shown in FIG. 3, the valve device 17 is provided with a gate 20 as an intermediate gate located at the center of three intermediate frame portions of the product cavity 13, and the valve device 17A is shown in FIGS. In addition, the gate 20A, which is a peripheral frame gate, is provided at four positions on the peripheral frame portion of the product cavity 13.

  Next, a method for manufacturing the molded body 1 using the mold apparatus will be described. In molding, first, after arranging a plurality of thin members 2 at intervals in 13 product cavities of the movable mold 12, the mold clamping device of the injection molding machine is movable with the fixed mold 11 with a constant mold clamping force. The mold 12 is closed and a product cavity 13 is formed between them as shown in FIG. A molten thermoplastic resin, which is a thermoplastic molding material, is injected into the fixed mold 11 from the nozzle of an injection molding machine. This resin (not shown) is filled into the product cavity 13 from the runner in the manifold, the material passage 19 of the valve devices 17 and 17A, the gates 20 and 20A, and the resin J in the material passage 19 is always in a molten state. It is kept.

  In this filling, the following control is performed in the present invention. First, both the gates 20 and 20A are closed by fitting the gate closing portion 23 of the valve pin 21. First, the gate 20 communicating with the three intermediate frame portions of the product cavity 13 is opened and the intermediate frame portion 3 is opened. After the resin is filled in the place, the gate 20 communicating with the four places of the peripheral frame portion of the product cavity 13 is opened, and the resin is filled in the four places of the peripheral frame portion. That is, after the resin filling from the gate 20 to the intermediate frame portion 3 is started, the peripheral frame portion 4 is filled with the resin J from the other gate 20A. When the thickness of the molded body 1 is as thin as 0.40 mm or less, as shown in FIG. 4, the opening time after opening the intermediate gate 20 is about 0.2 to 0.3 seconds, and the intermediate gate 20 is When closed, the peripheral frame gate 20A is opened almost simultaneously. In this way, by filling the intermediate frame 3 with the resin first and delaying the resin filling to the surrounding peripheral frame 4, the resin J can be satisfactorily filled into the intermediate frame 3 located on the center side. it can.

  Then, after the resin J in the product cavity 13 is cooled and solidified, the fixed mold 11 and the movable mold 12 are opened, and the molded body 1 remaining on the movable mold 12 side is ejected by an ejection pin (not shown). Extruded and released. Thereafter, the mold is closed again, the above steps are repeated, and the molding is repeated.

  As described above, in this embodiment, corresponding to claim 1, a plurality of fixed molds 11 and movable molds 12 that are opened and closed with each other to form product cavities 13 with each other when the mold is closed, A plurality of thin-walled members 2 arranged at intervals using a mold apparatus provided with a plurality of gates 20 and 20A provided in a fixed mold 11 which is a mold body forming a product cavity 13 and communicated with a material passage 19 2, an intermediate frame portion 3 formed between the thin members 2, 2, and a manufacturing method for manufacturing an injection molded body 1 including a peripheral frame portion 4 provided around the thin members 2, 2. After disposing a plurality of thin members 2 and 2 in the product cavity 13 at intervals, the fixed mold 11 and the movable mold 12 are closed, and resin filling from the gate 20 to the intermediate frame 3 is started. Since the peripheral frame 4 is filled with resin J from the other gate 20A, the fixed mold 11 and the movable mold 12 are molded. Therefore, when the product cavity 13 is formed between the two and the product cavity 13 is filled with the resin J from the gate 20, the resin is filled in the intermediate frame portion 3 first, and the resin is filled in the surrounding peripheral frame portion 4. Is delayed, the resin J is satisfactorily filled in the intermediate frame portion 3 located on the center side.

  As described above, in this embodiment, the thin member 2 is the foam metal 5 corresponding to the third and ninth aspects. Therefore, when the resin J is injected into the product cavity 13, the resin J becomes the foam metal 5. A molded body 1 is obtained in which the frame parts 3 and 4 made of the resin J and the foam metal 5 forming the thin member 2 are integrated into the pores.

  Thus, in this embodiment, corresponding to claim 4, a plurality of fixed molds 11 and movable molds 12 that are opened and closed with each other to form product cavities 13 when the mold is closed, and among these mold bodies, A plurality of thin-walled members 2 that are provided in a fixed mold 11 that forms a product cavity 13 and that are connected to a material passage 19 and are arranged at intervals, and between the thin-walled members 2 and 2 In the mold apparatus for producing the injection molded body 1 provided with the intermediate frame portion 3 formed on the outer peripheral portion 3 and the peripheral frame portion 4 provided around the thin members 2 and 2, the peripheral portion 4 corresponds to the peripheral frame portion 4. Since the peripheral gate 20A is arranged, the intermediate gate 20 is arranged corresponding to the intermediate frame portion 3, and the control means for controlling the resin filling start time between the peripheral gate 20 and the intermediate gate 20A is provided. Fill the intermediate frame 3 that is difficult to fill with the resin first, and move to the surrounding frame 4 By starting delays the resin filling, it is possible to perform the injection molding of the molded body 1 with an intermediate frame part 3 satisfactorily.

  FIG. 5 shows a second embodiment of the present invention. The same reference numerals are given to the same parts as those of the first embodiment, and detailed description thereof will be omitted. In this example, the peripheral frame 4 of the product cavity 13 is shown. A side gate 31 in the direction intersecting with the mold opening / closing direction is provided at the location, and the gate 20 of the valve device 17A is connected to the side gate 31. The side gate 31 is formed at the joint between the fixed mold plate 16 of the fixed mold 11 and the movable mold 12 when the mold is closed.

  Therefore, also in this example, the resin filling into the intermediate frame portion 3 is started first, and then the resin filling into the peripheral frame portion 4 is performed, so that the resin J is placed on the intermediate frame portion 3 located on the center side. Fills well.

  6 to 9 show a third embodiment of the present invention. The same reference numerals are given to the same portions as those of the above-described embodiments, and detailed description thereof will be omitted. This is an example of applying.

  The fixed mold 11 is provided with a runner stripper plate 16A laminated on the back side of the fixed side mold plate 16 (on the opposite side to the movable mold 12). Runners 25, 25A and 25A, which are material passages for branching the resin J injected from the nozzle of the injection molding machine to the product cavity 13, are formed between the fixed side mold plate 16 and the runner stripper plate 16A. .

  A central runner portion 26 is connected to the tip of the runner 25, and the central runner portion 26 is disposed at a position passing through the center of three intermediate frame portions of the product cavity 13. Further, side runner portions 27, 27 are connected to the tips of the runners 25A, 25A, and these side runner portions 27, 27 are arranged at positions passing through the outside of the width direction edge portion 4B of the product cavity 13. Yes. A center sprue 28 and a pin gate 28G in the mold opening / closing direction are provided between the center runner portion 26 and the product cavity 13 corresponding to the three intermediate frame portions. Located in the center. Further, a side sprue 29 in the mold opening / closing direction is connected to the side runner part 27, and a pin gate 29G is provided at the tip of the side sprue 29. Between the pin gate 29G position and the product cavity 13, the mold is provided. Side gates 31 are provided in the opening / closing direction and the crossing direction. The ends of the plurality of side sprues 29 are connected by a side gate runner portion 32. The side gate 31 and the side gate runner portion 32 are formed at the joint of the fixed mold plate 16 of the fixed mold 11 and the movable mold 12 when the mold is closed.

  The fixed mold 11 is filled with a resin J that fills the product cavity 13 from the pin gates 28G and 29G by providing a valve device (not shown) between the nozzle of the molding machine and the runner portions 25 and 25A. Can be controlled.

  The central sprue 28 has a shape that shrinks toward the product cavity 13, and the pin gate 28 G having a smaller cross-sectional area than the sprue 28 is connected to the tip of the central sprue 28 and the product cavity 13. The pin gate 28G has a substantially circular cross section.

  Further, the side sprue 29 has a shape that shrinks toward the movable mold 12 side, and the tip gate and the side gate runner 32 are connected to the pin gate 29G having a smaller cross-sectional area than the sprue 29. The pin gate 29G has a substantially circular cross section.

  As shown in FIG. 9, the movable die 12 is provided with an advancing / retreating pin 35 that advances / retreats in the mold opening / closing direction and an advancing / retreating drive means 36 for advancing / retreating the advancing / retreating pin 35 corresponding to the pin gate 28G. 35 can appear in the product cavity 13.

  Next, a method for manufacturing the molded body 1 using the mold apparatus will be described. In molding, first, after arranging a plurality of thin members 2 at intervals in 13 product cavities of the movable mold 12, the mold clamping device of the injection molding machine is movable with the fixed mold 11 with a constant mold clamping force. The mold 12 is closed and a product cavity 13 is formed between them as shown in FIG. A molten thermoplastic resin J, which is a thermoplastic molding material, is injected into the fixed mold 11 from the nozzle of an injection molding machine. This resin J passes through the runner 25, passes through a plurality of central sprues 28 and pin gates 28G, is filled into three intermediate frame portions in the product cavity 13, and resin filling into the three intermediate frame portions is started. From the runners 25A and 25A, the resin J passes through the plurality of side sprues 29, the pin gate 29G and the side gate 31, and is filled into the cavity 13 from the periphery of the four peripheral frame portions of the product cavity 13. Thus, since the pin gate 28G is directly provided at the three intermediate frame portions of the product cavity 13, the resin is surely filled into the three intermediate frame portions.

  Then, after the resin J in the product cavity 13 is cooled and solidified, the fixed mold 11 and the movable mold 12 are opened. The resin J cured in the runners 25 and 25A and the sprues 28 and 29 is separated from the frame portion 3 of the molded body 1 at the pin gate 28G by the mold opening, and solidified in the side gate 31 at the pin gate 29G. When the space between the fixed mold plate 16 and the runner stripper plate 16A is opened, the resin J such as the runners 25 and 25A is moved together with the runner stripper plate 16A, and further fixed to the runner stripper plate 16A. The mold is released by opening the side mold plate 16. On the other hand, the molded body 1 remaining on the movable mold 12 side is ejected by an ejection pin (not shown) and released. Thereafter, the mold is closed again, the above steps are repeated, and the molding is repeated.

  In such a molding step, driving of the advance / retreat pin 35 by the advance / retreat driving means 36 will be described. In order to facilitate understanding of the description, the case where the thickness T of the intermediate frame 3 is 0.2 mm will be described as an example. As shown in FIG. 9, before the resin is injected and filled into the product cavity 13 from the pin gate 28G, the front end surface 35A of the advance / retreat pin 35 is substantially flush with the inner surface 13A of the product cavity 13 or substantially lower than the inner surface 13A. For example, about 0.1 mm smaller than the thickness T. By doing so, the resin J is smoothly filled without the tip of the advance / retreat pin 35 preventing the flow of the resin J from the pin gate 28G into the product cavity 13. The inner surface 13A is a cavity forming surface on the movable mold 12 side. Then, after the resin J is filled into the product cavity 13 from the pin gate 28G, the advance / retreat pin 35 moves toward the pin gate 28G before the resin J is cured, and between the front end surface 35A of the advance / retreat pin 35 and the pin gate 28G. A thin portion 3A is formed in which the thickness t of the resin J is made thinner than the thickness T of other portions. In this case, the thickness t is preferably set to 1/3 or less of the thickness T. The movement of the advance / retreat pin 35 is performed before the opening of the fixed mold 11 and the movable mold 12, and as described above, the resin in the sprue 28 from the frame portion 3 of the molded body 1 at the pin gate 28G by the mold opening. At this time, since the thin portion 3A is formed at the tip of the pin gate 28G, an excessive force is not applied to the other portions of the intermediate frame portion 3, and the thin portion 3A portion can be inserted into the sprue 28. Resin J is separated. Incidentally, the hole 3B formed in the trace of the advance / retreat pin 35 is closed with a resin or the like after the molded body 1 is released, or is filled with an adhesive when the other body is bonded. To do.

  Then, after releasing the molded body 1, as described above, the mold closing is performed again, and before the resin is filled into the product cavity 13, the advance / retreat pin 35 again has the tip of the advance / retreat pin 35. The surface 35A is set to the same surface position as the inner surface 13A of the product cavity 13 or a position substantially lowered from the inner surface 13A, and the above-described steps are repeated and molding is repeated.

  As described above, in this embodiment, after the resin filling from the pin gate 28G as the gate to the intermediate frame portion 3 is started, the resin J is filled into the peripheral frame portion 4 from the side gate 31 as the other gate. A side gate 31 as a peripheral frame gate is arranged corresponding to 4 and a pin gate 28G as an intermediate gate is arranged corresponding to the intermediate frame part 3 to control the resin filling start time between the pin gate 28G and the side gate 31 Since the means is provided, the same operations and effects as those of the first embodiment are obtained.

  As described above, in this embodiment, the movable die 12 which is another mold body is provided with the advancing / retreating pin 35 corresponding to the intermediate gate pin gate 28G corresponding to the fifth aspect. After filling the resin J, the advance / retreat pin 35 is moved into the product cavity 13 so that the resin J in the pin gate 28G and the resin J in the product cavity 13 can be well separated when the mold is opened.

Thus, in this embodiment, corresponding to claim 7, the resin J from the runner 25 as the material passage is filled into the product cavity 13 from the pin gate 28G as the intermediate gate, and is movable with the fixed die 11 as the mold body. Since the resin J in the pin gate 28G and the resin J in the product cavity 13 are separated by opening the mold 12, the resin J is separated at the pin gate 28G when the fixed mold 11 and the movable mold 12 are opened. In the cavity 13, the molded body 1 composed of the frame portions 3 and 4 formed by solidifying the resin J and the thin member 2 remains, and the molded body 1 is obtained by taking out the molded body 1. Corresponding to claim 8, since the advance / retreat pin 35 advances / retreats to the tip of the pin gate 28G, after the resin J is filled in the intermediate frame portion 3, the advance / retreat pin 35 moves to the pin gate 28G. Since closing the 28G, resin of the resin J and product cavity 13 in the pin gate 28G is disconnected, injection molded body 1, the resin J is satisfactorily filled into the intermediate frame section 3 is obtained.

  FIG. 10 shows a fourth embodiment of the present invention. The same reference numerals are given to the same portions as those of the first embodiment, and detailed description thereof is omitted. In this example, the resin J is moved from the pin gate 28G to the product cavity. After filling in 13, before the resin J hardens, the advance / retreat pin 35 moves toward the pin gate 28 G toward the pin gate 28 G and closes the pin gate 28 G, and is molded at the pin gate 28 G by opening the mold. The frame part 3 of the body 1 and the resin J in the sprue 28 are smoothly separated.

  FIG. 11 shows a fifth embodiment of the present invention. The same reference numerals are given to the same parts as those of the above-mentioned embodiments, and detailed description thereof will be omitted. In this example, the front peripheral surface of the advance / retreat pin 35 is shown in FIG. A tapered fitting portion 35B is provided on the inner surface 13B of the product cavity 13 on the fixed mold 11 side to be engaged with the fitting portion 35B, and the pin gate 28G is formed in the fitting concave portion 37. Is provided. The depth H of the fitting recess 37 is preferably about 0.1 mm smaller than the thickness T, and the depth H is preferably about 1/3 to 2/3 of the thickness T.

  After the resin J is filled into the product cavity 13 from the pin gate 28G, the advance / retreat pin 35 moves toward the pin gate 28G to the position of the gate pin 28G before the resin J hardens, and the fitting portion of the advance / retreat pin 35 Since the pin gate 28G is closed by fitting the 35B into the fitting recess 37, the frame portion 3 of the molded body 1 and the resin J in the sprue 28 are smoothly separated at the pin gate 28G by mold opening.

  Thus, in the present embodiment, a tapered fitting portion 35B is provided on the front peripheral surface of the advance / retreat pin 35, and the fitting concave portion 37 that engages with the fitting portion 35B is formed as a fixed side mold plate of the fixed die 11. By forming the inner surface 13B as the 16 cavity forming surface, the pin gate 28G opened to the fitting recess 37 can be reliably closed by fitting the advance / retreat pin 35 and the fitting recess 37.

  FIG. 12 shows a sixth embodiment of the present invention, where the same reference numerals are given to the same parts as those of the above-described embodiments, and detailed description thereof is omitted. In this example, the side gate 31 is not used, The pin gate 29G is provided corresponding to the peripheral frame portion 4, and the advance / retreat pin 35 is provided corresponding to the pin gate 29G. Similar to the second and third embodiments, the advance / retreat pin 35 of the pin gate 29G is provided. Similarly to the fourth embodiment, the fitting portion 35B and the fitting recess 37 can be provided corresponding to the pin gate 29G.

  FIG. 13 shows a seventh embodiment of the present invention. The same reference numerals are given to the same parts as those of the above-described embodiments, and detailed description thereof will be omitted. In this example, instead of the pin gates 28G and 29G, The slit gates 28G ′ and 29G ′ are used, and the cross sections of the slit gates 28G ′ and 29G ′ are substantially linear at the place where the product cavity 13 communicates. Also in this example, after the resin filling from the slit gate 28G ′ corresponding to the intermediate frame portion 3 to the intermediate frame portion 3 is started, the peripheral frame portion 4 is filled with the resin J from the slit gate 29G ′ because it is another gate. Therefore, the same operations and effects as the above-described embodiments are achieved.

  As described above, in this embodiment, in correspondence with claim 2, resin J is filled into intermediate frame portion 3 from slit gate 28G ', which is a gate having a substantially linear cross section. In addition, since the cross section of the slit gate 28G, which is an intermediate gate, is formed in a substantially linear shape, the resin J can be more satisfactorily filled.

  In addition, this invention is not limited to the said Example, A various deformation | transformation implementation is possible. For example, the shape of the runner portions 26 and 27 can be selected as appropriate. Moreover, as a molded object which has a thin member, if it has a thin member, it can apply to the injection molded object of various shapes. In addition, as a thin-walled member, even the hot water of the thickness exceeding 0.40 mm is applicable.

It is a perspective view of the molded object which shows Example 1 of this invention. FIG. 4 is a cross-sectional view of the mold body showing the manufacturing process of the molded body, showing the mold closing time. It is a top explanatory drawing explaining the position of the gate with respect to a molded object same as the above. It is explanatory drawing explaining the opening / closing timing of a gate same as the above. It is sectional drawing of the principal part of the type | mold body which shows Example 2 of this invention. It is sectional drawing which shows Example 3 of this invention. It is explanatory drawing explaining the position of the resin channel | path and gate with respect to a molded object same as the above. It is a top explanatory drawing explaining the position of the gate with respect to a molded object same as the above. FIG. 9 is a cross-sectional view for explaining the driving of the advance / retreat pin. FIG. 9A shows the state before resin filling, and FIG. 9B shows the state after resin filling. It is sectional drawing explaining the drive of the advance / retreat pin which shows Example 4 of this invention. It is sectional drawing explaining the drive of the advance / retreat pin which shows Example 5 of this invention. It is sectional drawing of the principal part of the type | mold body which shows Example 6 of this invention. It is plane explanatory drawing explaining the position of the gate with respect to the molded object which shows Example 7 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Molded body 2 Thin member 3 Intermediate frame part 4 Peripheral frame part 5 Metal foam
11 Fixed type
12 Movable type
13 Product cavity
20 gates (intermediate gates)
20A Gate (peripheral frame gate)
25,25A Runner (material passage)
28 Central sprue (material passage)
28G pin gate (intermediate gate)
28G 'slit gate (intermediate gate)
29 Side sprue (material passage)
29G pin gate (peripheral frame gate)
29G 'slit gate (peripheral frame gate)
35 Advance / Retreat Pin
35A Tip surface

Claims (9)

A mold apparatus comprising a plurality of mold bodies that open and close to each other to form product cavities when the mold is closed, and a plurality of gates that are provided in the mold bodies that form the product cavities of the mold bodies and communicate with the material passages To produce an injection molded body having a plurality of thin-walled members arranged at intervals, an intermediate frame formed between the thin-walled members, and a peripheral frame provided around the plurality of thin-walled members In this manufacturing method, after arranging a plurality of thin members at intervals in the product cavity, the mold body is closed, and resin filling from the gate to the intermediate frame is started, and then another gate A method for manufacturing an injection-molded article, wherein the peripheral frame portion is filled with a resin. 2. The method of manufacturing an injection-molded article according to claim 1, wherein the intermediate frame portion is filled with resin from a gate having a substantially linear cross section. The mold apparatus for an injection-molded article according to claim 1, wherein the thin member is a foam metal. A plurality of molds that open and close to each other to form product cavities when the mold is closed, and gates that are provided in the molds that form the product cavities of these molds and communicate with the material passages, are arranged at intervals. In the mold apparatus for producing an injection molded body comprising a plurality of thin-walled members, an intermediate frame portion formed between the thin-wall members, and a peripheral frame portion provided around the plurality of thin-wall members, A peripheral frame gate is disposed corresponding to the frame portion, an intermediate gate is disposed corresponding to the intermediate frame portion, and a resin filling start time between the peripheral frame gate and the intermediate gate is controlled. A mold apparatus for an injection molded product. 5. The mold apparatus for an injection-molded article according to claim 4, wherein the other mold body is provided with an advancing / retreating pin for advancing / retreating in the product cavity corresponding to the intermediate gate. 5. A mold apparatus for an injection-molded article according to claim 4, wherein the intermediate gate has a substantially linear cross section. The resin from the material passage is filled into the product cavity from the intermediate gate, and the resin in the intermediate gate and the resin in the product cavity are separated by opening the mold. The mold apparatus of the injection-molded body according to any one of claims 4 to 6. 6. The mold apparatus for an injection-molded article according to claim 5, wherein the advance / retreat pin advances and retreats to the tip of the gate. The mold apparatus for an injection-molded article according to any one of claims 4 to 8, wherein the thin member is a foam metal.

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