JP5872663B1 - INJECTION DEVICE, MOLDING DEVICE, AND MOLDED PRODUCT MANUFACTURING METHOD - Google Patents

Abstract

An object of the present invention is to expand the degree of freedom of selection of reinforcing fibers that can be input into a plasticizing apparatus and to form a molded article of a composite material having various mechanical properties at low cost. The plasticizing apparatus includes a barrel having a supply port capable of supplying a reinforcing material, a screw accommodated in the barrel, a drive unit that rotationally drives the screw, and a barrel. A hopper 35 for supplying a base material therein and a reinforcing material supply device 40 capable of supplying at least two kinds of reinforcing materials into the barrel 33 from the supply port 44 are provided. [Selection] Figure 2

Description

  The present invention relates to a plasticizing device, an injection device, a molding device, an extruder, and a method for manufacturing a molded product.

  Some molded articles molded by the injection molding method are made of a composite material in which reinforcing fibers such as glass fibers and carbon fibers are mixed in a base resin. By using a composite material as a material, weight reduction and mechanical strength enhancement can be achieved.

  For example, in the automotive field, the materials of parts are changed from metal to composite materials such as carbon fiber reinforced resin and glass fiber reinforced resin with the aim of further improving the fuel efficiency of gasoline cars or improving the mileage of hybrid cars and electric cars. Replacing and reducing the weight of the vehicle body by this is being studied.

  Conventionally, a manufacturer of a molded product generally manufactures a molded product of a composite material by using a pellet provided by a material manufacturer and mixed with the composite material in advance. For example, Patent Document 1 discloses a method for manufacturing a composite material pellet in which long fibers such as glass fibers and carbon fibers are mixed in a resin.

  Composite pellets, especially pellets mixed with carbon fibers, are expensive. This is because carbon fiber is expensive and undergoes a compounding process for mixing with resin, a pelletizing process for processing into pellets, and the like. For this reason, in the field of aircraft, the introduction of composite materials is progressing, but the cost is an obstacle to the introduction to mass-produced products such as automobile parts.

  Therefore, a technique for forming a molded article of a composite material without using a composite pellet containing reinforcing fibers has been developed. For example, Patent Documents 2 and 3 propose a molding technique in which reinforcing fibers such as glass fibers are directly mixed when a resin is melted in a barrel of a plasticizer of an injection unit.

  Patent Document 4 proposes a method for manufacturing a molded article in which reinforcing fibers are introduced from a vent opening opened in a barrel of a plasticizing apparatus.

JP 2009-242616 A JP 2008-515682 A JP 2007-203638 A JP 2014-166712 A

  However, the conventional plasticizing apparatuses as disclosed in Patent Documents 2 to 4 are such that only one type of reinforcing fiber is added to and mixed with the molten resin, so that the freedom of material selection is reduced. There was a problem that the degree was narrow. Since one type of carbon fiber and one type of glass fiber are introduced into the barrel, there is a limit in adding various characteristics to the obtained composite material.

  In general, in composite materials, pitch-based carbon fibers and PAN-based carbon fibers are used as carbon fibers. PAN-based carbon fibers have a property that they are excellent in tensile strength but not high in bending rigidity. Pitch-based carbon fiber has a characteristic of high bending rigidity.

  Conventionally, it has been common technical knowledge to introduce only one type of carbon fiber into a plasticizer. For example, when PAN-based carbon fiber is mixed, the bending strength is enhanced even if the tensile strength can be enhanced. There was a problem that I could not. On the other hand, when pitch-type carbon fibers are mixed, there is a problem that even if the bending rigidity can be strengthened, the tensile strength is not improved and the cost is increased.

  In addition, when carbon fibers are introduced into the barrel of the plasticizing apparatus, there is a problem in that one type of carbon fiber has a problem of poor dispersibility, and the desired physical properties cannot be improved.

Therefore, the present invention has been made in view of the above-mentioned problems of the prior art, and has expanded the degree of freedom of selection of reinforcing fibers that can be input into a plasticizing apparatus, and is a molded article of composite material having various mechanical properties. It is an object of the present invention to provide an injection apparatus, a molding apparatus, and a method for manufacturing a molded product that can be molded at low cost.

In order to achieve the above object, an injection apparatus according to the present invention comprises:
A barrel having a supply port capable of supplying a reinforcing material;
A screw housed in the barrel;
A drive unit for rotationally driving the screw;
A hopper for supplying a base material into the barrel;
A reinforcing material supply device capable of supplying at least two types of reinforcing materials made of continuous fibers into the barrel from the supply port;
An injection mechanism for supplying the molding material in which the reinforcing material is dispersed from the barrel, measuring the molding material and injecting the molding material into a mold;
It is characterized by providing.

  In addition, a molding apparatus according to the present invention includes the above-described injection apparatus.

In addition, the method for producing a molded product according to the present invention includes:
Supply the base material to the heated barrel from the hopper, melt the base material by the heat of the heated barrel,
At least two kinds of reinforcing materials composed of continuous fibers , supplying reinforcing materials having different properties that complement each other into the barrel, and mixing the reinforcing material with the base material in the barrel to obtain a composite material Generate
The composite material is injected into a mold to form a molded product.

It is a side view which shows one Embodiment of the injection molding machine with which the plasticizing apparatus by this invention is applied. It is sectional drawing of the injection apparatus provided with the plasticizing apparatus of FIG. It is a figure explaining the condition where two types of carbon fibers are mixed with resin. It is a figure explaining the condition where two types of carbon fibers are mixed with resin.

Hereinafter, an embodiment of an injection device, a molding device, and a method for manufacturing a molded product according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a diagram showing an outline of an injection molding machine (molding apparatus) 10 to which a plasticizing apparatus according to an embodiment of the present invention is applied. In FIG. 1, reference numeral 12 indicates the entire injection apparatus. Reference numeral 14 denotes a mold clamping device (mold opening / closing device, opening / closing device) of an injection molding machine. The injection molding machine 10 includes an injection device 12 including a plasticizing device 30 and a mold clamping device 14.

  In the mold clamping device 14, a fixed die plate (fixed platen) 15 is fixed on the frame 11 on one end side on the injection device 12 side. A link housing (pressure receiving plate) 16 is installed on the other end side of the frame 11. A movable die plate (movable platen) 17 is movably disposed on the frame 11 between the fixed die plate 15 and the link housing 16. A fixed die 18 is attached to the fixed die plate 15, and a moving die 19 is attached to the moving die plate 17. The fixed mold 18 and the movable mold 19 form a cavity 20 for molding a molded product.

  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, a toggle link mechanism 22 is provided as an opening / closing mechanism for opening / closing the movable mold 19 with respect to the fixed mold 18.

  The toggle link mechanism 22 is connected to the cross head 24. The cross head 24 is provided with a nut portion 25, and a ball screw 27 driven by a servo motor 26 is screwed into the nut portion 25.

  FIG. 1 shows a state where the toggle link mechanism 22 is extended. When the cross head 24 moves to the right and the toggle link mechanism 22 extends, the moving die plate 17 moves forward and the mold is closed. Then, after the movable mold 19 comes into contact with the fixed mold 18 and is closed, the toggle link mechanism 22 is further extended to generate a large mold clamping force. On the contrary, when the cross head 24 moves to the left in FIG. 1, the toggle link mechanism 22 is bent, so that the moving die plate 17 moves backward to perform mold opening.

  Next, the injection device 12 will be described. Here, FIG. 2 is a cross-sectional view showing the configuration of the injection device 12.

  The injection device 12 according to this embodiment is a preliminary plasticizing type injection device. The injection device 12 is roughly divided into a plasticizing device (extruder, plasticizing unit, plasticizing mechanism) 30 that melts, kneads and mixes the molding material (base material, reinforcing material, composite material) and sends it out. It has an injection part (injection mechanism) 32 that measures the molding material and injects it into the cavity 20 in the mold.

The plasticizing device 30 is configured as a single-screw extruder, for example, and a screw 34 in which a flight 31 is spirally inserted is inserted into the barrel 33. The barrel 33 is provided with a hopper 35 for supplying, for example, resin pellets 60 (molding material, base material) processed into a pellet shape into the barrel 33. A heater 36 for heating the barrel 33 is disposed on the outer periphery of the barrel 33.

  Reference numeral 37 is a motor (drive unit) that drives the screw 34. A pulley 38 a is attached to the rear end portion of the screw 34. A pulley 38 b is attached to the rotating shaft of the screw drive motor 37, and the rotation of the screw drive motor 37 is transmitted to the screw 34 through a belt 39 wound around the pulleys 38 a and 38 b. In the plasticizing device 30, when the screw 34 is rotated by the screw drive motor 37, the base material supplied from the hopper 35 into the barrel 33 is melted.

  In the plasticizing apparatus 30 according to the present embodiment, the resin as the base material is supplied by, for example, pellets 60, and a plurality of types of reinforcing fibers (reinforcing material, molding material) are mixed (mixed) with the molding material. A heterogeneous reinforcing fiber feeding device (reinforcing fiber feeding device, reinforcing material feeding device, reinforcing material feeding device) 40 as described later is provided so that a composite material can be generated. A plurality of types of reinforcing fibers are supplied into the barrel 33 from vent holes (input ports, supply ports) 44 opened in the barrel 33. The vent hole 44 is originally a hole for exhausting volatile components in the molten resin, but in this embodiment, the vent hole 44 is used as a reinforcing fiber supply port.

  The molding material (composite material) is fed to the front of the barrel 33 while a plurality of types of reinforcing fibers are mixed with the base resin. The tip of the barrel 33 is connected to an injection cylinder 50 that constitutes the injection unit 32. An injection plunger 51 is slidably fitted to the injection cylinder 50, and the injection plunger 51 is moved forward and backward by a drive cylinder 52.

  The molding material extruded from the plasticizing device 30 to the injection cylinder 50 is measured in the process in which the injection plunger 51 moves backward. The molding material (composite material) stored in the injection cylinder 50 is filled into the cavity 20 formed by the fixed mold 18 and the movable mold 19 from the nozzle 48 by advancing the injection plunger 51.

  Next, the different type reinforcing fiber feeding device 40 for supplying reinforcing fibers into the barrel 33 of the plasticizing device 30 will be described.

First, materials used in the plasticizing apparatus 30 of this embodiment will be described.
Various resins such as nylon resin, polycarbonate resin, polypropylene resin, polyethylene resin, acrylic resin, and ABS resin are used as the base material of the composite material in which a plurality of types of reinforcing fibers are mixed. It is done. These arbitrary resins are used as the resin pellet 60, for example.

  Various materials such as glass fiber, carbon fiber, aramid fiber, and vegetable fiber are used for the reinforcing fiber (reinforcing material).

  As described above, there are various types of reinforcing fibers.

  There are various types of fibers such as glass fibers, carbon fibers, aramid fibers, plant fibers, and the like, and any reinforcing fiber can be used if classified from the viewpoint of differences in materials (raw materials, raw materials).

  Even from the viewpoint of materials, even reinforcing fibers classified as the same type of reinforcing fibers may have different characteristics due to differences in manufacturing method, chemical structure, and the like.

  That is, for example, aramid fibers include para-aramid fibers having high mechanical strength such as tensile strength, wear resistance, and impact resistance, and meta-aramid fibers having high heat resistance and flame resistance. Carbon fibers include PAN-based carbon fibers excellent in tensile strength and pitch-based carbon fibers excellent in bending rigidity. And in this embodiment, even if it is a reinforced fiber classified into the same kind of reinforced fiber from the viewpoint of such a material, about the reinforced fiber from which a characteristic differs by differences in a manufacturing method, a chemical structure, etc., it is different reinforced fiber ( Different reinforcing fibers, different reinforcing materials).

  The reinforcing fiber includes a short fiber such as cotton and a continuous fiber (long fiber) in which a single fiber is continuous like a thread. In this embodiment, a reinforcing fiber in the form of a continuous fiber is used. ing.

  In the case of carbon fiber, for example, a continuous fiber having a thickness of about 5-7 μm is used as a fiber bundle in which tens of thousands to several tens of thousands are bundled. Similarly, with regard to glass fibers and aramid fibers, a fiber bundle in which continuous fibers are bundled is mounted on a heterogeneous reinforcing fiber feeding device 40 as described below.

  As shown in FIG. 2, a plurality of, for example, three reinforcing fiber loadings, in which the fiber bundles of reinforcing fibers (reinforcing fiber windings, reinforcing material windings) are detachably loaded in the heterogeneous reinforcing fiber feeding device 40. Parts (reinforcing material loading parts) 41A, 41B, 41C are provided.

  The reinforcing fiber loading units 41A, 41B, and 41C are detachably loaded with, for example, reinforcing fiber windings formed of different types of reinforcing fibers. In this embodiment, for example, a pitch-based carbon fiber wound body 42 is loaded in the reinforcing fiber loading part 41A, and a PAN-based carbon fiber wound body 43 is loaded in the reinforcing fiber loading part 41B.

  In the reinforcing fiber loading portions 41A and 41B, the pitch-based carbon fiber wound body 42 and the PAN-based carbon fiber wound body 43 are simultaneously rotated toward the plasticizing apparatus 30 while the fiber bundles 42A and 43A are fed out. ing.

  The fiber bundles 42A and 43A of such different types of carbon fibers are drawn out to the vent hole 44 opened in the barrel 33, and are continuously fed as continuous fibers into the barrel 33 from the vent hole 44.

  The plasticizing apparatus (injection apparatus) according to the present embodiment is configured as described above. Next, operations and effects will be described in relation to a method for manufacturing a molded product.

  In FIG. 2, when the barrel 33 is heated by the heater 36 and reaches a predetermined temperature, the resin pellet 60 is put into the barrel 33 from the hopper 35. At the same time, the screw 34 in the barrel 33 is rotated.

  The resin pellet 60, which is a base material and is formed in a pellet shape, is sent toward the tip side of the barrel 33 while being melted by the heat of the barrel 33 heated by the heater 36 by the rotation of the screw 34.

  In this way, when melting and kneading of the base material is started, the fiber bundle 42A of pitch-based carbon fibers and the fiber bundle 43A of PAN-based carbon fibers are fed from the vent hole 44 into the barrel 33 from the different type reinforcing fiber feeding device 40. Continuously and simultaneously.

  In this case, the fiber bundle 42A of pitch-based carbon fibers and the fiber bundle 43A of PAN-based carbon fibers are entangled with the flight 31 of the rotating screw 34 and are continuously drawn into the barrel 33. Then, in the process of mixing with the molten resin sent to the position of the vent hole 44, each of the single fibers constituting the fiber bundles 42A and 43A is sandwiched between the flight 31 and the inner surface of the barrel 33. Due to the shear force that is sometimes received, the fiber is cut into a relatively long pitch-based carbon fiber single fiber piece 42B or a PAN-based carbon fiber single fiber piece 43B (see FIG. 3). Then, the screw 34 is fed to the tip of the barrel 33 while being kneaded so as to be uniformly dispersed in the resin by the rotation of the screw 34.

  In this way, in the plasticizing apparatus 30, the molten resin in which the pitch-based carbon fiber single fiber pieces 42B and the PAN-based carbon fiber single fiber pieces 43B are mixed, that is, the composite material, is sent to the tip of the barrel 33, Further, it is pushed out from the tip of the barrel 33 into the injection cylinder 50.

  1 and FIG. 2, the metering is performed while the injection plunger 51 is retracted, and the resin in which the pitch-based carbon fiber and the PAN-based carbon fiber stored in the injection cylinder 50 are mixed, that is, the composite material, The injection plunger 51 is injected into the cavity 20.

  According to the embodiment as described above, the resin pellets 60 are supplied from the hopper 35, and the fiber bundle 42 </ b> A in which pitch-based carbon fibers are continuous and the fiber bundle in which PAN-based carbon fibers are continuous are supplied by the different type reinforcing fiber feeding device 40. Since 43A is simultaneously supplied into the barrel 33 of the plasticizing apparatus 30, they are mixed by the rotation of the screw 34 to produce a composite material in which pitch-based carbon fibers and PAN-based carbon fibers are dispersed in the base resin. can do.

  This composite material makes use of the characteristics of PAN-based carbon fiber, which has high tensile strength, and compensates for the weak point of weak bending rigidity by mixing pitch-based carbon fiber with high bending rigidity, improving both tensile strength and bending rigidity. It becomes possible to produce material. The mixing ratio of the pitch-based carbon fiber and the PAN-based carbon fiber can be adjusted by adjusting the feeding speed or by changing the number of single fibers of the fiber bundle 42A of the pitch-based carbon fiber and the fiber bundle 43A of the PAN-based carbon fiber. It is possible to achieve a desired mixing ratio.

  In addition, the resin pellet 60 supplied from the hopper 35 does not need to use a high-cost resin pellet mixed with carbon fiber in advance, so that the material cost can be greatly reduced, and the resin pellet 60 is molded from a composite material. Contributes to the realization of mass production of molded products.

  Moreover, the different kind of reinforcing fiber feeding device 40 can simultaneously supply two or more different kinds of reinforcing fibers to the barrel 33 simultaneously. In the example described above, pitch-based carbon fibers and PAN-based carbon fibers are combined as reinforcing fibers, but the present invention is not limited to this.

  By the way, the continuous fiber of carbon fiber may have poor dispersibility in the process of being mixed in the screw 34 after being supplied into the barrel 33. In that case, for example, if PAN-based carbon fibers and glass fibers are combined and mixed in the barrel 33, the glass fibers having good dispersibility enter the gaps between the carbon fibers having poor dispersibility, so that the overall dispersibility is improved. It can be expected to improve the tensile strength and the like.

  Other combinations of reinforcing fibers include carbon fibers and plant fibers, glass fibers and plant fibers, aramid fibers and carbon fibers, aramid fibers and glass fibers, and aramid fibers and plant fibers. As described above, since the degree of freedom of selection of materials is expanded, new composite materials with improved mechanical properties that have never been possible can be directly developed at the molding site, and moreover, molding products using the composite materials can be developed. It becomes possible to realize mass production.

  In the above embodiment, the reinforcing fiber is supplied into the barrel 33 using the vent hole 44 originally opened in the barrel 33, but the present invention is not limited to this. For example, a hole for supplying reinforcing fibers may be provided in the barrel 33 not at the vent hole 44 but at a position where the resin is melted by the screw 34.

  Further, the number of reinforcing fiber supply holes is not limited to one, and a plurality of reinforcing fiber supply holes may be provided. For example, as shown in FIG. 4, the barrel 33 may be provided with three reinforcing fiber supply holes (reinforcing material supply holes) 62A, 62B, and 62C.

  For example, the continuous fiber GF of glass fiber is supplied from the reinforcing fiber supply hole 62A located at the most upstream position, and the continuous fiber CF of carbon fiber is supplied from the intermediate reinforcing fiber supply hole 62B. A continuous fiber AF of aramid fibers is supplied from the hole 62C. According to this, since the continuous fiber GF of glass fiber is supplied from the most upstream, the dispersibility of the carbon fiber and the aramid fiber mixed thereafter can be easily increased.

  Although the present invention has been described with reference to the embodiment applied to the preliminary plasticizing type injection apparatus, the present invention is not limited to this. For example, the present invention can be applied to an in-line type injection device in which the plasticizing device 30 and the injection unit are integrated. Furthermore, the plasticizing apparatus 30 can also be configured as an extruder mainly for melting and kneading molding materials and molding pellets.

  Moreover, in this embodiment, although the base material was made into the pellet form, this invention is not limited to this. For example, as the base material of the present invention, a base material that is chopped into pellets may be used.

DESCRIPTION OF SYMBOLS 10 ... Injection molding machine (molding apparatus), 12 ... Injection apparatus, 14 ... Clamping apparatus, 15 ... Fixed die plate (fixed platen), 16 ... Link housing (pressure receiving plate), 17 ... Moving die plate (movable platen), 18 ... fixed mold, 19 ... moving mold, 20 ... cavity, 22 ... toggle link mechanism, 30 ... plasticizer, 32 ... injection part, 33 ... barrel, 34 ... screw, 35 ... hopper, 36 ... heater, 40 ... Dissimilar reinforcing fiber feeding device (reinforcing fiber feeding device, reinforcing material feeding device, reinforcing material feeding device), 41A to 41C ... Reinforcing fiber loading unit (reinforcing material loading unit), 42 ... Pitch-based reinforcing fiber roll, 44 PAN-based carbon fiber wound body, 42A ... pitch-based reinforcing fiber bundle, 43A ... PAN-based carbon fiber bundle, 42B ... pitch-based reinforcing fiber piece, 43B ... PAN-based carbon fiber piece, 44 ... Ben Holes (filling hole, inlet, feed inlet), 50 ... injection cylinders, 51 ... injection plunger, 60 ... resin pellets (molding material, a resin base material)

Claims (7)

A barrel having a supply port capable of supplying a reinforcing material;
A screw housed in the barrel;
A drive unit for rotationally driving the screw;
A hopper for supplying a base material into the barrel;
A reinforcing material supply device capable of supplying at least two types of reinforcing materials made of continuous fibers into the barrel from the supply port;
An injection mechanism for supplying the molding material in which the reinforcing material is dispersed from the barrel, measuring the molding material and injecting the molding material into a mold;
An injection apparatus comprising: The injection device according to claim 1, wherein the reinforcing material is two or more types of reinforcing materials having different materials. The injection device according to claim 1, wherein the reinforcing material is two or more types of reinforcing materials having the same material and different characteristics. The injection device according to claim 1, wherein the reinforcing material is two or more types of reinforcing materials that are different in material and characteristics. An injection molding apparatus comprising the injection apparatus according to any one of claims 1 to 4 . Supply the base material to the heated barrel from the hopper, melt the base material by the heat of the heated barrel,
At least two kinds of reinforcing materials composed of continuous fibers , supplying reinforcing materials having different properties that complement each other into the barrel, and mixing the reinforcing material with the base material in the barrel to obtain a composite material Generate
A method for producing a molded product, wherein the composite material is injected into a mold to mold a molded product. The method for producing a molded article according to claim 6, wherein the reinforcing material is a combination of pitch-based carbon fibers and PAN-based carbon fibers.

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