JP6522456B2 - Method and apparatus for molding composite material molding - Google Patents

Description

  Embodiments of the present invention relate to a method and apparatus for molding a composite material molded article in which reinforcing fibers such as carbon fibers are mixed.

In the injection molding method, a composite material in which reinforcing fibers such as carbon fibers and glass fibers are mixed in a resin of a base material may be used. By using the composite material, the mechanical strength of the molded article can be enhanced and the weight thereof can be reduced.
When a resin mixed with reinforcing fibers is injection molded, the reinforcing fibers tend to be oriented in the flow direction of the resin, and there is a problem that the molded product is warped or the strength in a specific direction is weakened. For this reason, in injection molding using a composite material, various improvements have conventionally been added to ameliorate the defects of the warp of a molded article and the directionality of strength.

  For example, in Patent Document 1, after the fiber-filled resin material is first filled in the mold cavity, the mold cavity is expanded, and then the fiber-filled resin material is filled from the direction intersecting the first resin flow direction. An injection molding method for forming a layered molded article is disclosed.

  Further, in Patent Document 2, a first injection device for forming a base material layer containing a fiber material and a second injection device for forming a surface layer containing a fiber material are used. A molding method is disclosed in which the blending ratio of the fiber material is different between the resin molding material of the injection device and the resin molding material of the second injection device.

Japanese Patent Application Laid-Open No. 63-315218 JP, 2011-173344, A

  However, in the molding method of Patent Document 1, pellets in which reinforcing fibers are mixed in advance are used as materials to be supplied to the injection device. Further, in the molding method of Patent Document 2, chopped fibers obtained by cutting a bundle of reinforcing fiber filaments into a predetermined length are used as the material.

  Since such pellets containing reinforcing fibers and resin molding materials containing chopped fibers originally have a short fiber length, fiber breakage is likely to occur when they are filled in the cavity. For this reason, there is a problem that the intended purpose of reinforcing fibers can not be achieved without remaining long fibers.

  The present invention has been made in view of the above-mentioned problems of the prior art, in which the flow direction of the resin material in the mold cavity is changed between the injection step of the first layer and the injection step of the second layer. An object of the present invention is to provide a method and an apparatus for molding a composite material molded article, in which a high strength molded article can be obtained by leaving long reinforcing fibers in the molded article without breakage.

  In order to achieve the above object, a molding apparatus for a composite material molded article according to the present invention comprises a barrel having an insertion port into which continuous reinforcing fibers are injected at a position different from a supply port of a base material; An injection device having a screw to be accommodated, a first fixed mold for molding a first layer of a molded article, a second fixed mold for molding a second layer, and the first fixed mold And a moving mold that is combined with each other in a compatible manner with each of the second fixed molds, and a mold replacement mechanism that replaces the combination of the fixed mold and the moving mold when the mold is opened. And a mold clamping apparatus for opening and closing and mold clamping the mold apparatus, wherein the mold apparatus comprises the cavity and the continuous reinforcing fiber mixed in the cavity of the first layer from the first direction. The first flow path for filling the molding material, and the first direction from the direction different from the first direction A second flow path for filling the molding material into two layers cavity, is characterized in that it has a.

  Further, the method of molding a composite material molded article according to the present invention uses the above-described composite material molding apparatus, and in the injection step, the molding material in the cavity of the first layer from the first flow path to the first direction And a molding material in a direction different from the first direction from the second flow path in the cavity of the second layer so as to be superimposed on the intermediate molded product consisting of the first layer and a first injection step of injecting Forming a composite material molded article in which the first layer and the second layer are laminated such that the orientation directions of the reinforcing fibers are different from each other. It is.

It is a side view showing the outline of the injection molding machine for enforcing the molding method of the composite material molded article by one embodiment of the present invention. It is a cross-sectional view which shows the injection device of the injection molding machine of FIG. FIG. 2 is a cross-sectional view showing two sets of molds used to form a composite material molded article according to an embodiment of the present invention. It is sectional drawing of the metal mold | die which shows the formation process of the composite material molded article by embodiment of this invention.

Hereinafter, an embodiment of a method and apparatus for molding a composite material molded article according to the present invention will be described with reference to the attached drawings.
FIG. 1 is a schematic view of an injection molding machine 10 for carrying out a method of molding a composite material molded article according to an embodiment of the present invention. The injection molding machine 10 is composed of an injection device 12 and a mold clamping device 14.

  First, the mold clamping device 14 will be described. In the mold clamping device 14, a movable die plate (movable plate) 17 is disposed between the fixed die plate (fixed plate) 15 and the link housing (pressure receiving plate) 16. The fixed die plate 15 and the link housing 16 are connected by a plurality of (for example, four) tie bars 21.

  In this embodiment, two sets of molds 22 and 24 are used to form a molded article in which two layers of composite material in which reinforcing fibers are mixed with resin are laminated. Among these, the first mold 22 is composed of a fixed mold 22a and a moving mold 23a (or a moving mold 23b), and is a mold for forming a first layer of a molded product. The second mold 24 includes a fixed mold 22b and a moving mold 23b (or a moving mold 23a), and is a mold for molding the second layer. The fixed dies 22a and 22b are attached to the fixed die plate 15, and the movable dies 23a and 23b are attached to the movable die plate 17 via a rotary die plate (intermediate plate) 25 of a rotary type. The rotary die plate 25 will be described later.

  The mold clamping device 14 is provided with a toggle link link mechanism 18 as a mold opening and closing mechanism. The toggle link mechanism 18 connects the link housing 16 and the movable die plate 17. The toggle link mechanism 18 includes a cross head 27. The cross head 27 is provided with a nut portion 28 so that a ball screw 26 driven by a servomotor 29 is screwed into the nut portion 28. It has become.

  In FIG. 1, the toggle link linkage 18 is shown in an extended, mold closed condition. When the cross head 27 is moved to the right in FIG. 1 driven by the servomotor 29, the toggle link mechanism 18 is extended and the movable die plate 17 is advanced to perform the mold closing operation. Then, by further extending the toggle link mechanism 18, the tie bar 21 extends and a large mold clamping force is generated. Conversely, when the cross head 27 moves to the left in FIG. 1, the toggle link mechanism 26 is bent, so the movable die plate 17 is retracted and the mold opening operation is performed.

  Next, the injection device 12 will be described. In the case of this embodiment, two injection devices 12 are installed in parallel so that the molding material can be injected simultaneously into two sets of the first mold 22 and the second mold 24. The injection device 12 has the same configuration.

FIG. 2 shows the configuration of the injection device 12. In this embodiment, a pre-plasticizing injection device 12 is used. The injection device 12 has a plasticizing device 30 for melting, kneading and mixing the molding material and feeding it out, and an injection unit 32 for measuring the molten molding material and injecting it into a cavity in the mold. .
A screw 34 is inserted into the barrel 33 of the plasticizing device 30. A flight 31 is provided spirally on the outer periphery of the screw 34. Further, in the barrel 33, for example, a hopper (base material supply port) 35 for charging the resin pellet 60 processed into a pellet shape into the barrel 33 is provided. Further, a heater 36 is disposed on the outer peripheral portion of the barrel 33.

  A pulley 38 a is attached to the rear end of the screw 34, and a pulley 38 b is attached to the screw drive motor 37. The screw drive motor 37 rotates the screw 34 via a belt 39 wound around the pulleys 38a and 38b.

  In the plasticizing apparatus 30 according to the present embodiment, in order to mix (mix) the reinforcing fibers with the resin of the base material, the barrel 33 receives the fiber bundle 66 of the reinforcing fibers at the downstream position of the heater 36. 40 is designed to open. As the inlet 40, the vent hole provided in the barrel 33 can be used to exhaust the volatile component contained in the molten resin. The resin melted by the heating by the heater 36 and the rotation of the screw 34 is sent to the front of the barrel 33 while being mixed with the reinforcing fiber introduced from the inlet 40. The tip end of the barrel 33 is connected to an injection cylinder 50 that constitutes the injection unit 32.

  The molding material delivered from the plasticizing device 30 to the injection cylinder 50, in this case, the molding material in which the reinforcing fiber is mixed in the resin, is injected from the nozzle 42 into the mold by advancing the injection plunger 51 by the drive cylinder 52. It is supposed to be

  Next, a mold for molding a molded article will be described with reference to FIG. FIG. 3A shows a cross section of the first die 22 and the second die 24 attached to the rotary type swiveling die plate 25 and the stationary die plate 15. FIG. 3 (b) shows the cavity molding surface of the fixed mold 22 a of the first mold 22, and FIG. 3 (c) shows the cavity molding surface of the fixed mold 22 b of the second mold 24.

  In this embodiment, a two-layered mold is formed using two sets of molds consisting of the first mold 22 and the second mold 24. In the first mold 22, a first cavity for forming an intermediate molded product 62 consisting of a first layer by the fixed mold (first fixed mold) 22a and the moving mold 23a (or the moving mold 23b) 54 are formed. In the second mold 24, with the intermediate molded product 62 remaining in the moving mold 23b (or moving mold 23a), the moving mold 23b (or moving mold 23a) and the fixed mold (second fixing) The mold 22 b forms a second cavity 55 for molding the final molded product on which the second layer is laminated so as to be superimposed on the intermediate molded product 62.

  In this embodiment, as shown in FIG. 1, the moving molds 23a, 23b are attached to the rotary die plate 25 in a 180 ° symmetrical position with respect to the pivot axis 44. The moving molds 23a and 23b are molds of the same shape. The pivoting die plate 25 is driven by a pivoting drive mechanism 46 so that it can pivot 180 °. The turning die plate 25 and the turning drive mechanism 46 constitute a die replacement mechanism.

  As shown in FIGS. 3B and 3C, the flow direction of the molding material is orthogonal between the fixed mold 22a for forming the first layer and the fixed mold 22b for forming the second layer. The flow paths of the molding material are respectively set to (cross at right angles).

  In the case of the fixed mold 22 a for the first layer, the flow path 65 is set such that the molding material flows in the first cavity 54 in the direction of the arrow A, for example. On the other hand, in the case of the fixed mold 22b for the second layer, the flow having different directions and shapes such that the molding material flows in the second cavity 55 in the direction of the arrow B in the direction orthogonal to the arrow A. The path 66 is set.

  Next, a method of molding a composite material molded article to be carried out using the above-described injection molding machine will be described.

First, materials used for molding will be described.
For example, various resins such as nylon resin, polycarbonate resin, polypropylene resin, polyethylene resin, acrylic resin, and ABS resin are used as the base resin. As shown in FIG. 2, these resins are processed into resin pellets 60 and introduced from the hopper 35 into the barrel 33 of the plasticizing device 30.

Carbon fibers, glass fibers, aramid fibers, plant fibers and the like can be used as the reinforcing fibers (reinforcing material) mixed in the resin, and any of them can be used as a reinforcing fiber.
Reinforcing fibers are divided into single fiber lumps such as cotton and continuous fibers (long fibers) in which the fibers are continuous like yarns, in view of the form of fibers. Used in the present embodiment are reinforcing fibers in the form of continuous fibers. In the case of carbon fibers, for example, a bundle of several tens to several tens of thousands of continuous fibers having a thickness of about 5 to 7 μm to form fiber bundles is used.

  As shown in FIG. 2, a fiber bundle 66 composed of such reinforcing fibers is drawn from the reel 68 toward the barrel 33 of the plasticizing device 30, and is kept in the form of continuous fibers from the inlet 40 into the barrel 33. It is thrown in.

  On the other hand, the resin pellet 60 is sent forward by the rotating screw 34 while being melted by the heat of the heater 36, and the resin of the base material is melted and kneaded. At this time, when the fiber bundle 66 of reinforcing fibers is fed into the barrel 33 from the inlet 40, the fiber bundle 66 is entangled in the flight 31 of the rotating screw 34 and drawn into the barrel 33.

  Then, the fibers forming the fiber bundle 66 are dispersed in the molten resin while being cut by the shear force received when they are pinched between the flight 31 and the inner surface of the barrel 33. In this case, since continuous fibers are used for the fiber bundle 66, it is possible to secure the length of the reinforcing fibers without being broken finely even after being mixed.

  Thus, in the plasticizing device 30, kneading of the reinforcing fiber and the resin is performed. The molten resin mixed with reinforcing fibers, ie, the composite material, is fed to the tip of the barrel 33 and is further extruded from the tip of the barrel 33 into the inside of the injection cylinder 50.

Next, FIG. 4 is a view for explaining an injection process which is performed while rotating the rotary type revolving die plate 25 and replacing the combination of dies.
FIG. 4 (a) shows the injection process when molding the first intermediate molded product 62 consisting of the first layer. FIG.4 (b) has shown the injection process when turning the turning die plate 25 180 degree from the position of Fig.4 (a). FIG. 4 (c) shows an injection process in which the intermediate molded article 62 and the final molded article 68 are simultaneously molded.

  In FIG. 4A, when the mold is clamped in the first stage, the movable mold 23a is combined with the fixed mold 22a among the movable molds 23a and 23b attached to the rotary type intermediate die plate 25. , Forms a first cavity 54 for molding the intermediate molded product 62. The other moving mold 23 b and the fixed mold 22 b form a second cavity 55 for molding the final molded product 68. At this stage, the intermediate mold 62 is not contained in the second cavity 55.

  After clamping, the molding material is injected and filled into the first cavity 54 from the injection cylinder 50a on the first mold 22 side of the two injection cylinders 50a and 50b through the flow path 65. At this time, the molding material is not filled into the second cavity 55 from the injection cylinder 50 b on the second mold 24 side. Thereafter, when the molding material hardens under holding pressure, mold opening is performed in a state where the intermediate molded product 62 molded by the first mold 22 adheres to the moving mold 23a.

  In such an intermediate molded product 62, as shown in FIG. 3 (b), since the mixed molding material of reinforcing fibers flows from the direction of arrow A into the first cavity 54, the orientation of the reinforcing fibers is also in this direction. Become.

  When the mold opening is completed, the rotary type swivel die plate 25 pivots 180 °, and the positions of the movable molds 23a and 23b are switched. After clamping, as shown in FIG. 4 (b), the movable mold 23 b is combined with the fixed mold 22 a to form a first cavity 54 for molding the intermediate molded product 62, and the movable mold With the intermediate molded product 62 attached, the fixed mold 24a and the second cavity 55 for the final molded product 68 will be formed.

  Next, as shown in FIG. 4C, the molding material in which the reinforcing fibers are mixed from the two injection cylinders 50a and 50b is the first cavity 54 and the second mold in the first mold 22, respectively. The second cavities 55 in the cavity 24 are simultaneously injected. In the injection process at this stage, the intermediate molded product 62 and the final molded product 68 are simultaneously molded.

  In the final molded product 68, as shown in FIG. 3C, the mixed molding material of reinforcing fibers passes through the flow path 66 from the direction orthogonal to the case of the intermediate molded product 62, and the second cavity 55 Flow into For this reason, the orientation of the reinforcing fibers is perpendicular to the first layer.

  In the final molded product 68, since long reinforcing fibers are left without breakage and the orientations of the long reinforcing fibers intersect in the first layer and the second layer, the bending strength is obtained regardless of the direction. It is possible to obtain a high-strength molded article with significantly improved elastic modulus and the like.

Thereafter, the mold is opened and the final molded product 68 is taken out. After that, the turning die plate 25 is turned to replace the movable molds 23a and 23b, and after the mold is clamped, the same injection process is repeated. Thus, it is possible to efficiently mold the intermediate molded article 62 and the final molded article 68 simultaneously in one molding cycle.
The method and apparatus for molding a composite material molded article according to the present invention have been described above by way of preferred embodiments, but in the present invention, a slide-type intermediate die plate is used instead of the rotary mold replacement mechanism. It is also possible to apply a die changing mechanism attached with a moving die. Also, the flow paths in different directions may be formed not only on the fixed mold side but also on the moving mold side.

DESCRIPTION OF SYMBOLS 10 injection molding machine 12 injection device 14 clamping device 15 fixed die plate (fixed board) 16 link housing (pressure receiving board) 17 movable die plate (movable board) 18 toggle link Mechanism, 22a: first fixed mold, 22b: second fixed mold, 24a, 24b: moving mold, 25: pivoting die plate, 26: ball screw, 27: crosshead, 30: plasticizing device 32: injection part, 33: barrel, 34: screw, 35: hopper, 40: insertion port for reinforced fiber, 50: injection cylinder, 54: first cavity, 55: second cavity, 60: resin pellet, 62 ... intermediate molded article, 65 ... first channel, 66 ... second channel

Claims (4)

An injection device having a barrel having a feeding port for feeding continuous reinforcing fibers at a position different from a feeding port of the base material, and a screw housed in the barrel;
Compatible with a first fixed mold for molding a first layer of a molded article, a second fixed mold for molding a second layer, and each of the first fixed mold and the second fixed mold A moving mold to be combined with a mold apparatus comprising:
A mold replacement mechanism that replaces the combination of a fixed mold and a moving mold when the mold is opened,
A mold clamping device for opening and closing the mold device and clamping the mold device;
The mold apparatus is different from a first flow path for filling a molding material in which the continuous reinforcing fibers are mixed in the base material from the first direction in the cavity of the first layer, and the first direction. And a second flow path for filling the molding material into the cavity of the second layer from the direction.   The mold replacement mechanism is a rotary mold replacement mechanism in which a pair of the movable molds are disposed 180 ° symmetrically with respect to the pivot axis on a pivot die plate pivotable about a pivot axis. An apparatus for forming a composite material molded article according to claim 1.   The direction in which the molding material flows from the first flow path into the cavity of the first layer and the direction in which the molding material flows from the second flow path into the cavity of the second layer are orthogonal to each other. Item 3. An apparatus for forming a composite material molded article according to item 1 or 2. The composite material forming apparatus according to any one of claims 1 to 3
In the injection process, a first injection process of injecting the molding material into the cavity of the first layer from the first flow path in a first direction, and an intermediate molded product formed of the first layer are overlapped. And a second injection step of injecting a molding material in a direction different from the first direction from the second flow passage in the cavity of the second layer,
What is claimed is: 1. A method of forming a composite material molded article, comprising: molding a composite material molded article in which the first layer and the second layer are laminated such that the orientation directions of reinforcing fibers are different.

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