JP6424284B1 - Molding method of fiber reinforced molded product - Google Patents

Abstract

The present invention provides a method for molding a fiber-reinforced molded product that can increase the strength of the molded product. A fiber reinforced plastic material 1 having a cross section which is longer and shorter than a molding space formed by a plurality of molds 3 and which is formed by impregnating a fiber material with a thermoplastic resin, The molding space is placed in a vertically long posture, heated to be deformable, and then deformed by pressurizing in the longitudinal direction. The cross-sectional area of the molding space is made of the fiber-reinforced plastic material. It is set to be smaller than the cross-sectional area. [Selection] Figure 6

Description

  The present invention relates to a method for molding a fiber reinforced molded product for molding a fiber reinforced plastic material constituted by impregnating a fiber material with a thermoplastic resin.

  The fiber reinforced plastic material is excellent in mechanical properties, light weight, corrosion resistance, and the like, and thus is widely deployed in various applications. Since the fiber reinforced plastic material is formed by impregnating a fiber material with a thermoplastic resin, the fiber reinforced plastic material is also advantageous in terms of molding and has attracted attention. For example, a method for forming a bolt, which is a fiber-reinforced molded product, has already been proposed using the fiber-reinforced plastic material. Specifically, a rod-shaped material made of fiber-reinforced plastic material is put into a first mold and formed into a round bar material, and a round bar material is formed to form a recess portion and a screw portion on the formed round bar material. Is placed in a second mold and heated. When the round bar material becomes deformable, the round bar is inserted into the round bar material from one end side where the recess part of the both ends in the length direction of the round bar material is formed, and the thread part is molded. By forming a forming column into the round bar from the other end side of the bar to the back side, a recess part and a screw part are formed to form a bolt (for example, Patent Document 1).

JP-A-6-185514

  In the configuration of Patent Document 1 described above, when a forming rod and a forming column are plunged into a round bar material, the pressure at the plunged portion can be increased, and the strength at that portion can be increased, but the portion that has not been plunged However, the strength of the bolt (molded product) could not be increased, and there was room for improvement.

  Then, this invention is made | formed in view of this situation, and makes it a subject to provide the shaping | molding method of the fiber reinforced molded product which can raise the intensity | strength of a molded product.

The method for molding a fiber-reinforced molded product according to the present invention uses a first mold having a first upper mold and a first lower mold that form an elliptical molding space, and uses the first lower mold in an open state. A large number of strip-shaped materials are arranged in the vertical direction in a semi-elliptical concave portion of the side mold, and the first upper mold and the first lower mold are heated to deform the strip-shaped material. After making it possible, the first upper mold and the first lower mold are clamped to form a fiber-reinforced plastic material having an elliptical cross section, which is different from the first mold. A second mold having a second upper mold and a second lower mold that form a molding space having a shape is used, and the elliptical fiber-reinforced plastic material molded by the first mold is opened in the mold state. Add the second upper mold and the second lower mold in a state of being placed in a vertically long posture in the semicircular recess of the second lower mold. And, by pressurizing a deformable state going on a fiber-reinforced plastic material of the longitudinal orientation said second upper mold and the longitudinal direction by clamping by the second lower mold, a circular cross section shape In the method for molding a fiber reinforced molded product, the fiber reinforced plastic is formed when the elliptical fiber reinforced plastic material is arranged in a vertically long posture on the second lower mold of the second mold. The lower part of at least one end portion of the lengthwise both ends orthogonal to the cross section of the material is molded in a state where the fiber-reinforced plastic material is held in a vertically long posture .

According to the present invention, a vertically long fiber reinforced plastic material that is deformable by being put into a molding space in a vertically long posture and being deformed by being placed in a vertically long posture and having a cross section that is vertically longer than the molding space in the longitudinal direction It is deformed so as to spread in the lateral direction by applying pressure. The lateral molding space that is not filled with the deformed fiber-reinforced plastic material is filled. Then, after the molding space is filled with the fiber reinforced plastic material, the fiber reinforced plastic material is pressurized throughout, so that the strength of the molded product to be molded can be increased.
In addition, when the fiber reinforced plastic material is arranged in the vertically long posture on the lower mold, the fiber reinforced plastic material is in the vertically long posture at the lower part of at least one end portion in the longitudinal direction perpendicular to the cross section of the fiber reinforced plastic material. If it shape | molds in the state hold | maintained, it can deform | transform reliably the fiber-reinforced plastic material of a vertically long attitude | position in the vertical direction, and can suppress generation | occurrence | production of inferior goods.

  Moreover, it is preferable that the shaping | molding method of the fiber reinforced molded product which concerns on this invention is set so that the cross-sectional area of the said molding space may become smaller than the cross-sectional area of the said fiber reinforced plastic material.

  As described above, by setting the cross-sectional area of the molding space to be smaller than the cross-sectional area of the fiber-reinforced plastic material, the entire fiber-reinforced plastic material after filling the molding space is removed from the mold. A clamping force can be applied, and the strength of the molded product to be molded can be reliably increased.

  As described above, according to the present invention, a fiber-reinforced plastic material having a longitudinally longer and laterally shorter cross section than the molding space is placed in the molding space in a vertically long posture to be in a deformable state and added in the vertical direction. It is possible to provide a method for molding a fiber reinforced molded product that can increase the strength of the molded product by pressurizing the fiber reinforced plastic material after the fiber reinforced plastic material is deformed by pressing to fill the molding space.

(A) is a perspective view of a carbon fiber reinforced plastic material having a flat plate shape, and (b) is a perspective view showing a state in which a number of strips of the carbon fiber reinforced plastic material of (a) are stacked up and down. . (A) is a perspective view which shows the molded object which shape | molded the carbon fiber reinforced plastic material shown in FIG.1 (b) in cross-sectional shape ellipse, (b) is shaping | molding of cross-sectional shape ellipse of FIG. It is a perspective view which shows the molded article which shape | molded the article in circular cross-sectional shape. FIG. 2 is a longitudinal sectional view of a mold showing a state immediately before molding a strip-shaped carbon fiber reinforced plastic material stacked in a vertical direction as shown in FIG. is there. It is a longitudinal cross-sectional view of a metal mold | die which shows the state which closed the metal mold | die of FIG. 3 and shape | molded the molded object of cross-sectional shape ellipse. It is a longitudinal cross-sectional view of the metal mold | die which shows the state just before shape | molding the molded object of cross-sectional shape ellipse in cross-sectional shape circle. It is a longitudinal cross-sectional view of the metal mold | die which shows the state which took out the two molded products shape | molded. It is a perspective view which shows the shape of the length direction one end part of the lower metal mold | die.

  FIG. 1A shows a material 2 for molding a fiber-reinforced plastic material 1 used in the method for molding a fiber-reinforced molded product of the present invention. The material (also referred to as prepreg) 2 shown here is formed by impregnating a carbon fiber with a phenoxy resin (thermoplastic epoxy resin) and molding it into a plate shape. The material 2 includes a material in which fibers are arranged in only one direction, and a material in which a woven fabric in which fibers are woven vertically and horizontally is impregnated with resin. Further, the carbon fiber content (fiber volume content: Vf) relative to the phenoxy resin is set to 50%. However, the more the content exceeds 50%, the more advantageous in terms of strength. You may set to less than% content rate. The length of the carbon fiber is over 5 mm, which makes it impossible to form by injection molding, and in particular, the length exceeds 10 mm (the longer is better, but the longer is 50 mm). It is preferable in terms of strength later.

  FIG. 1A shows a material 2 (also referred to as a prepreg) 2 formed by impregnating a carbon fiber with a phenoxy resin (thermoplastic epoxy resin) to form a rectangular sheet. FIG. 1B shows the material 2 cut into a long and narrow strip, and a large number of the cut strip-shaped materials 2A are stacked in the vertical direction. As shown in FIG. 3, the strip-shaped material 2 </ b> A in which a large number of strip materials 2 </ b> A shown in FIG. The carbon fiber reinforced plastic material 1 having an elliptical cross-sectional shape is formed by putting in an elliptical concave portion 15 in a state where a large number of them are stacked in the vertical direction and clamping (FIG. 4). Then, when the carbon fiber reinforced plastic material 1 having an elliptical cross-sectional shape is molded, the molding is performed in the semicircular recess 14 (see FIG. 3) that forms the lower half of the molding space 18 having a circular cross-sectional shape to be described later. By inserting the carbon fiber reinforced plastic material 1 having an elliptical shape (a shape having a vertically long and a laterally short cross section) in a vertically long posture and heating and pressing in the vertical direction, the rod-shaped fiber reinforced molded product 20 having a circular cross section is formed. (See FIGS. 2B and 6). The longitudinal dimension H1 of the carbon fiber reinforced plastic material 1 shown in FIG. 2A is larger than the longitudinal dimension H2 of the circular molding space 18 shown in FIG. 4, and the carbon fiber reinforced plastic material 1 shown in FIG. The horizontal (width) dimension W1 is set to be smaller than the horizontal (width) dimension W2 of the circular molding space 18 shown in FIG.

As shown in FIGS. 3 to 6, the mold 3 includes an upper mold 4 positioned on the upper side and a lower mold 5 positioned on the lower side. The upper mold 4 is attached to a movable member 8 that is moved up and down by a lifting mechanism (not shown) of male molds 6 and 7 having two types of shapes. One male mold 7 constitutes a first upper mold that forms a semi-elliptical molding space. The other male mold 6 constitutes a second upper mold that forms a semicircular molding space. The molding lower mold 5 includes a fixed base 9, a cylindrical intermediate member 10 fixed to the upper end of the fixed base 9, and an upper end member 11 fixed to the upper end of the intermediate member 10. Recesses 12 and 13 are formed in the upper end so that the male molds 6 and 7 are opened upward. The semicircular recess 14 and the semi-elliptical shape are formed so as to be recessed further downward at the lower ends of the recesses 12 and 13. A recess 15 is formed. The mold part in which one semi-elliptical recess 15 is formed constitutes the first lower mold. The mold part in which the other semicircular recess 14 is formed constitutes a second lower mold. Here, the first lower mold and the second lower mold are constituted by one mold. Configure the semicircular recess 16 and a second mold that will be formed a circular shape of the molding space 18 at the left side of the semicircular recess 14 of the top member 11 which is formed so as to be recessed upward to the left of male 6 An elliptical molding space 19 is formed by a laterally semi-elliptical concave portion 17 formed so as to be recessed upward in the right male mold 7 and a laterally semi-elliptical concave portion 15 on the right side of the upper end member 11 . Configure the mold .

  As shown in FIG. 7, when the fiber reinforced plastic material 1 indicated by a two-dot chain line is arranged in a vertically long posture at one end portion in the length direction (axial direction) of the semicircular recess 14 of the lower mold 5. A locking portion 21 that locks the lower portion of one end portion in the length direction orthogonal to the cross section of the fiber reinforced plastic material 1 is formed continuously with the semicircular recess 14. The locking portion 21 includes a semicircular bottom wall portion 21A that supports the bottom surface of the elliptical carbon fiber reinforced plastic material 1, and a pair of flat side wall portions 21B that extend straight upward from both widthwise ends of the bottom wall portion 21A. , 21B. The distance between the side wall portions 21B and 21B is set to be the same as or slightly larger than the thickness of the elliptical carbon fiber reinforced plastic material 1. Therefore, by locking one end portion in the length direction of the elliptical carbon fiber reinforced plastic material 1 to the locking portion 21, the side wall of the carbon fiber reinforced plastic material 1 contacts the side wall portions 21B and 21B of the locking portion 21. By contacting, the carbon fiber reinforced plastic material 1 can be held in a vertically long posture. As described above, when the fiber reinforced plastic material 1 having an elliptical cross section is arranged in a vertically long posture on the lower mold 5, one end portion of both ends in the length direction perpendicular to the cross section of the fiber reinforced plastic material 1 is provided. If the fiber-reinforced plastic material 1 is molded in a state where the lower portion is locked and the fiber-reinforced plastic material 1 is held in the vertically long posture, the fiber-reinforced plastic material 1 in the vertically long posture can be reliably deformed, and the occurrence of defective products can be suppressed. Here, the locking portion 21 is provided only at one end portion in the length direction orthogonal to the cross section of the fiber reinforced plastic material 1, but the locking portion is provided at both end portions in the length direction orthogonal to the cross section of the fiber reinforced plastic material 1. Can also be implemented. Further, the upper mold 4 may be formed in correspondence with the locking portion 21 provided in the lower mold 5. It should be noted that an unnecessary portion having an elliptical cross section formed by the locking portion 21 remains at the end of the fiber reinforced molded product 20 having a circular cross section after being formed by deforming the fiber reinforced plastic material 1. Therefore, the unnecessary part is cut off by cutting or the like.

The procedure for molding the fiber-reinforced molded product of the present invention (here, the rod-shaped fiber-reinforced molded product) will be described. First, as shown in FIG. A large number of strip-shaped materials 2A shown in FIG. As shown in FIGS. 2 and 4, the strip-shaped material 2A disposed by heating the mold 3 is made deformable, and the upper mold 4 is lowered and clamped with the lower mold 5. The rod-shaped fiber-reinforced plastic material 1 having an elliptical cross section is formed. After molding, the mold is opened and naturally cooled for a predetermined time, and then the mold is opened and the rod-like fiber reinforced plastic material 1 is taken out. The taken-out rod-like fiber reinforced plastic material 1 is put in the semicircular recess 14 on the left side of the lower mold 5 and then the upper mold 4 is lowered to a predetermined position (see FIG. 5, in FIG. In this state, the mold temperature is set to 200 ° C. and heated for 15 minutes. By this heating, the upper mold 4 is lowered in order to apply pressure to the fiber-reinforced plastic material 1 in a vertically long posture that is in a deformable state from above. This vertically long fiber reinforced plastic material 1 is deformed so as to spread in the lateral direction by being pressurized in the longitudinal direction. The lateral molding space that is not filled with the deformed fiber reinforced plastic material 1 is filled. Then, after the molding space 18 is filled with the fiber reinforced plastic material 1, the strength of the molded product to be molded can be increased by pressurizing the fiber reinforced plastic material 1 throughout. Here, the pressing force of the mold 3 is 150 kg / cm ² , and the pressurizing time by the mold 3 is 30 minutes. When 30 minutes of pressurization time by the mold 3 elapses, the upper mold 4 is raised to open the mold, and after cooling for 6 hours by natural cooling, the fiber reinforced molded product 20 molded as shown in FIG. Take out. In FIG. 5, when the vertically long fiber reinforced plastic material 1 is formed into a circular and rod-like fiber reinforced molded product 20, a large number of the strip-shaped materials 2A shown in FIG. If it is arranged in a state where it is superposed in the vertical direction, the fiber reinforced plastic material 1 and the fiber reinforced molded product 20 are molded with the same pressure by one mold 3, and as shown in FIG. The fiber reinforced molded article 20 and the elliptical rod-like fiber reinforced plastic material 1 can be taken out simultaneously. The lower mold 5 is provided with an actuator (not shown) for separating the fiber reinforced molded product 20 and the fiber reinforced plastic material 1 attached to the lower mold 5 upward from the lower mold 5. Extrusion bars 22 and 22 that can move up and down are provided. When burrs are generated in the molded fiber reinforced molded product 20 and the fiber reinforced plastic material 1, an operation of removing the burrs is performed. The fiber reinforced molded product 20 formed into a rod-shaped member may be cut into a predetermined length, and a bolt (screw) may be manufactured by providing each of the cut with a helical screw portion and a head. In this embodiment, as described above, pressure is applied to form a rod-shaped fiber reinforced plastic material 1 having an elliptical cross section, and then pressure is applied to the molded fiber reinforced plastic material 1 to form a fiber reinforced molding having a circular cross section. The product 20 is molded. Thus, the fiber reinforced molded product 20 formed by pressing and compacting twice is advantageous in terms of strength as compared with the case where the fiber reinforced molded product is molded by one molding.

Further, when the mold 3 is clamped, the cross-sectional area of the left circular molding space 18 (see FIG. 4) is the cross-sectional area of the fiber-reinforced plastic material 1 (see FIG. 4) having an elliptical cross section (right side). The sectional area of the elliptical molding space 19 is set to be smaller. Specifically, the cross-sectional area of the circular molding space 18 is 113.1 mm ² , and the cross-sectional area of the elliptical fiber-reinforced plastic material 1 is 114.5 mm ² , but other values may be used. . Note that the greater the difference between these cross-sectional areas, the greater the strength of the fiber-reinforced molded product 20 formed by applying the pressing force of the mold 3 to the fiber-reinforced plastic material 1. The amount of will also increase. In addition, since the axial length of the circular molding space 18 is the same as the axial length of the elliptical fiber-reinforced plastic material 1, the volume of the circular molding space 18 is a fiber having an elliptical cross section. It is smaller than the volume of the reinforced plastic material 1. As described above, the cross-sectional area of the circular molding space 18 is set to be smaller than the cross-sectional area of the fiber-reinforced plastic material 1, so that the fiber-reinforced plastic material after filling the circular molding space 18 is used. The clamping force from the mold 3 can be applied to the entirety of 1, and the strength of the molded product to be molded can be reliably increased.

  As the thermoplastic resin used for the fiber reinforced plastic, a thermoplastic epoxy resin is preferably used, and examples thereof include a polyamide resin, a polyester resin, a polystyrene resin, a polyetherimide resin, and a polycarbonate resin.

  In addition, the shaping | molding method of the fiber reinforced molded product which concerns on this invention is not limited to embodiment, A various change is possible in the range which does not deviate from the summary of this invention.

  In the above-described embodiment, carbon fibers are used as the fibers. However, various metal fibers may be used in addition to glass fibers, aramid fibers, polyester fibers, and polyamide fibers.

  Moreover, in the said embodiment, although the elliptical thing was shown as a shape which has a vertically long and short cross section rather than a shaping | molding space, if it is a vertically long and short shape, it will be a triangle, a quadrangle, or a pentagon The thing of the above polygonal shape may be sufficient.

  Moreover, in the said embodiment, although the fiber reinforced plastic material was shape | molded from what piled up what was cut in strip shape, it is the material which consists of a fiber-containing thermoplastic resin previously shape | molded by the predetermined shape without cutting. A large number may be stacked, or a large number of materials of various shapes made of thermoplastic resin containing a fiber material may be stacked.

  Moreover, in the said embodiment, although it was made possible to shape | mold two moldings from which a shape differs with one metal mold | die, you may shape | mold two moldings from which a shape differs using two metal mold | dies.

DESCRIPTION OF SYMBOLS 1 ... Fiber reinforced plastic material, 2 ... Material (prepreg), 2A ... Strip-shaped material, 3 ... Mold, 4 ... Upper die, 5 ... Lower die, 6, 7 ... Male die, 8 ... Movable member, DESCRIPTION OF SYMBOLS 9 ... Fixing base, 10 ... Intermediate member, 11 ... Upper end member, 12, 13 ... Recessed part, 14 ... Semi-circular recessed part, 15 ... Semi-elliptical recessed part, 16 ... Semi-circular recessed part, 17 ... Semi-elliptical recessed part, 18 ... Circular molding space, 19 ... Elliptical molding space, 20 ... Fiber reinforced molded product, 21 ... Locking part, 21A ... Bottom wall part, 21B ... Side wall part, 22 ... Extrusion bar, H1, H2 ... Vertical dimensions , W1, W2 ... Horizontal dimensions

Claims (2)

Using a first mold having a first upper mold and a first lower mold that form an elliptical molding space, a strip-shaped material is placed in a semi-elliptical recess of the first lower mold in an open state. The first upper mold is disposed in a state in which a large number of the upper and lower molds are superposed in a vertical direction and the first upper mold and the first lower mold are heated to deform the strip-shaped material. And a first lower mold, and a second upper mold that forms a circular molding space different from the first mold by molding a fiber-reinforced plastic material having an elliptical cross section. Using a second mold having a second lower mold, the elliptical fiber-reinforced plastic material molded by the first mold is vertically long in the semicircular recess of the second lower mold in the mold open state. A vertically long posture in which the second upper die and the second lower die are heated and deformed in a state of being arranged in a posture. By pressurizing with longitudinal fiber-reinforced plastic material by clamping between the second lower mold and said second upper mold, the fiber-reinforced molded article cross section forming a circular fiber-reinforced molded article In the molding method,
When the elliptical fiber-reinforced plastic material is disposed in a vertically long posture on the second lower mold of the second mold, at least one end portion in the longitudinal direction perpendicular to the cross section of the fiber-reinforced plastic material A molding method for a fiber-reinforced molded article, wherein the lower part of the fiber-reinforced plastic material is molded in a state where the fiber-reinforced plastic material is held in a vertically long posture .   The method for molding a fiber-reinforced molded article according to claim 1, wherein a cross-sectional area of the molding space is set to be smaller than a cross-sectional area of the fiber-reinforced plastic material.

Images