JP2016043507A - Manufacturing method for preform and manufacturing method for fiber-reinforced composite material molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a preform in which a wrinkle generated on the preform can be efficiently avoided by predicting accurately a position at which tension is imparted to a prepreg and a direction of the tension which are required for preventing the generation of the wrinkle.SOLUTION: The manufacturing method for a preform shapes the preform while applying tension to a position of a fiber prepreg at which shear deformation angles of the fiber prepreg to be calculated by simulation using a shape-imparting analysis software is equal to 15° or more. It is preferable that the tension is applied in a bias direction relative to a fiber direction of the prepreg.SELECTED DRAWING: Figure 7B

Description

  In order to obtain a desired fiber-reinforced resin molded article, the present invention uses a preform manufacturing method and a preform for forming a sheet-shaped prepreg into a predetermined shape by male and female narrow pressure prior to the main molding. The present invention relates to a method for manufacturing a molded product of fiber reinforced composite material.

  Conventionally, for example, a technique for obtaining a fiber-reinforced resin molded product having a predetermined shape by heating and pressing a sheet-like prepreg formed by impregnating a reinforcing fiber with an uncured thermosetting resin in a molding die is known. (For example, refer to Patent Document 1).

  When manufacturing the fiber reinforced resin molded product, if it has a three-dimensional shape including a curved surface, a preform having a predetermined shape taking into account the shape of the final molded product from the sheet-shaped prepreg is prepared prior to the main molding. In addition, a technique for pre-shaping is also known.

  As a preform shaping method, for example, a method for obtaining a desired preform by shaping a prepreg while applying a tension in a direction substantially perpendicular to the narrow pressure direction of the male and female dies in order to suppress generation of wrinkles. Is also known (see, for example, Patent Document 2).

Republished WO 2004/018186 JP 2014-051077 A

  However, when forming a deep-drawn complex shape (for example, FIG. 1) such as a bucket seat 1 of an automobile in the above prior art, generation of wrinkles can be suppressed by applying tension to any location of the prepreg. It was very difficult to judge whether it was possible.

  In addition, even if the position to apply the tension that can suppress wrinkles can be identified by several trials and errors, it is necessary to carry out the same trial and error from the beginning if the layer structure changes, so the desired shaped product There is also a problem that the work man-hours for obtaining the cost increase and the cost increases.

  It was also unclear as to which direction the tension was applied relative to the direction of the reinforcing fiber in the prepreg, and that the generation of wrinkles could be suppressed with a smaller load.

  The present invention has been made in view of the above circumstances, and is efficiently generated in a preform by accurately predicting the position and direction of tension applied to the prepreg, which are necessary to prevent the generation of wrinkles. An object of the present invention is to provide a preform manufacturing method that can avoid wrinkles.

As a means for solving the above problems, the first aspect of the present invention is:
(1) A preform manufacturing method in which a sheet-like prepreg is shaped into a predetermined shape by narrow pressure of male and female dies prior to the main molding in order to obtain a desired fiber-reinforced resin molded product, and is shaped This is a preform manufacturing method in which a shape is applied while applying tension to a location of a prepreg where the shear deformation angle of the fabric prepreg calculated by simulation using analysis software is 15 ° or more.
(2) The preform manufacturing method according to (1), wherein tension is applied in a bias direction with respect to a fiber direction of the prepreg.
The second aspect of the present invention is
(3) A fiber-reinforced composite material for obtaining a molded article of a fiber-reinforced composite material having a three-dimensional shape by compression-molding the preform manufactured by the preform manufacturing method according to the above (1) or (2) with a molding die It is a manufacturing method of a molded article.

  The preform manufacturing method of the present invention can efficiently avoid wrinkles generated in the preform.

It is a molded article shape figure concerning an example of an embodiment of the present invention. It is a figure which shows the simulation result which concerns on an example of embodiment of this invention. It is a figure which shows the simulation result which concerns on an example of embodiment of this invention. It is a figure explaining the shear deformation angle which concerns on an example of embodiment of this invention. It is a figure explaining the shear deformation angle which concerns on an example of embodiment of this invention. It is a top view which shows the laminated body which concerns on an example of embodiment of this invention. It is process drawing which shows an example of embodiment of this invention. It is process drawing which shows an example of embodiment of this invention. It is process drawing which shows an example of embodiment of this invention. It is process drawing which shows an example of embodiment of this invention. It is process drawing which shows an example of embodiment of this invention. It is process drawing which shows an example of embodiment of this invention. It is process drawing which shows an example of embodiment of this invention.

First, a method for specifying a tension applying position, which is the first step in the preform manufacturing method of the present invention, will be described. The position where the tension is applied can be specified by the following steps [1] and [2].
[1] Obtain or create 3D CAD data of the shape to be shaped.
[2] Perform simulation assuming that the 3D CAD data is shaped with a fabric prepreg using the shape analysis software, and identify the location where the shear deformation angle of the fabric prepreg is 15 ° or more during shaping. To do.

(Acquisition or creation of 3D CAD data)
In the preform manufacturing method of the present invention, when specifying a position to apply tension, three-dimensional CAD data of a shape to be shaped is required.
If 3D CAD data exists at hand, it may be used. If 3D CAD data is not available, measure the coordinate data of the shape you want to shape at a desired interval using a layout machine (for example, product name: layout machine 96AS, manufactured by Tokyo Trading Techno System Co., Ltd.) It is possible to obtain 3D CAD data by inputting the data into 3D CAD software (for example, manufactured by Siemens PLM Software, product name: NX), and an optical 3D measuring device (for example, OTTO). It is also possible to obtain 3D CAD data by measuring the shape to be shaped using Vision Technology Gmbh (product name: kolibri move) and importing the data into 3D CAD software. Any method may be used, but it is preferable to use an optical three-dimensional measuring device because data can be easily created.

(Simulation using shaping analysis software)
It is possible to perform a simulation assuming that the three-dimensional CAD data is shaped with a prepreg using formability analysis software (for example, manufactured by Siemens PLM Software, product name: Fibersim).
Specifically, “PPG-PL-3K” is selected as the item “Material” in the shape analysis software for the three-dimensional CAD data of the bucket seat 1 of the automobile as shown in FIG. After inputting the value of “Fiber Spacing factor” at 0.5 or less, a desired simulation can be performed by selecting “Net Productivity”.

“Material” refers to the material used to shape the desired shape. Since the material used in the present invention is a prepreg, it is preferable to select “PPG-PL-3K”, which indicates a 3K plain weave prepreg, as “Material”.
“Fiber Spacing Factor” refers to the size of a mesh used for simulation. Although it may be appropriately selected according to the size of the shape to be shaped, it is preferable to input a value of 0.5 or less from the viewpoint of the accuracy of simulation.

(Shear deformation angle)
By performing the simulation, a shear deformation angle distribution 2 of the prepreg in the bucket seat shape can be obtained as shown in FIGS. 2A and 2B (in FIGS. 2A and 2B, a region where the shear angle is 0 ° or more and less than 15 °. 2A, the region of 15 ° or more and less than 30 ° is 2B, and the region of 30 ° or more is 2C.
The “shear deformation angle” as used herein refers to a change 4B generated as shown in FIG. 4 by the shaping simulation at an angle 4A (90 °) composed of the warp 3A and the weft 3B as shown in FIG. Yes, on the formability analysis software, it is called “Limit Angle”.

  It means that the larger the shear deformation angle, the larger the deformation amount required for shaping the prepreg into a desired shape, and the more likely wrinkles are generated. Accordingly, it is possible to more efficiently suppress the generation of wrinkles by selecting a place where a large amount of deformation is required and actively applying tension in the bias direction to easily cause shear deformation. The bias direction here is the direction of the longer diagonal line of the substantially rhomboid quadrilateral formed by shear deformation of the unit structure of the woven fabric that was square before shaping.

(Identification of the position to apply tension)
It is preferable to apply tension to the prepreg where the shear deformation angle is 15 ° or more.
According to the experience of the present inventors, in the simulation results carried out under the conditions described above, the region where the shear deformation angle is 0 ° or more and less than 15 ° can be shaped without any problem, and the shear deformation angle is 15 The region where the angle is between 30 ° and 30 ° indicates that attention is required for shaping. Similarly, when the shear deformation angle is 30 ° or more, it is difficult to shape manually. Therefore, it is effective to avoid wrinkles by shaping while applying a tension to a place where the shear deformation angle is 15 ° or more.

  By selecting “Generate Flat Pattern” after completion of the simulation by the formability analysis software, CAD data of the planar shape 9 developed two-dimensionally can be obtained. At that time, it is preferable to obtain CAD data having a planar shape after marking in advance a position where tension is applied in a three-dimensional state using the “Markers” function.

  Specifically, the portions 5A, 6A, 7A (2 places) and 8A where the shear deformation angle shown in FIG. 2A is 15 ° or more are two-dimensionally developed into the planar shape 9 by using the “Markers” function. In doing so, it is possible to mark 5B, 6B, 7B (2 places), 8B as shown in FIG. In addition, 5C, 6C, 7C (2 places) and 8C which are symmetrical with respect to 5B, 6B, 7B (2 places) and 8B from the central axis of the planar shape 9 can be marked simultaneously.

Next, the second step of the preform manufacturing method of the present invention will be described. The second stage of the present invention is to produce a preform through the following steps [1] to [6] in order.
[1] Cut the prepreg into the shape determined by the shape analysis software.
[2] After the cut prepreg is laminated to obtain a laminate, the laminate is placed in a preform mold. [3] The location of the laminate specified by the simulation is clamped.
[4] The laminate is heated with a heater while being clamped.
[5] A tension is applied to the heated laminate, and the laminate is shaped by pressing with a preform mold.
[6] After gradually removing the tension by removing the tension, the preform mold is opened and the shaped laminate is taken out.
However, when shaping one prepreg, the lamination operation in the above step [2] is omitted, and one prepreg is referred to as a laminate.

(Prepreg)
The form of the prepreg that can be used in the method for producing a preform of the present invention may be a UD prepreg in which reinforcing fibers are aligned in one direction, or a woven prepreg in which reinforcing fibers are woven. .
(Reinforced fiber)
Examples of the reinforcing fiber constituting the prepreg include carbon fiber, glass fiber, aramid fiber, high-strength polyester fiber, boron fiber, alumina fiber, silicon nitride fiber, and nylon fiber. Among these, carbon fiber is preferable because it is excellent in specific strength and specific elasticity.
(Thermosetting resin)
Examples of the thermosetting resin constituting the prepreg include an epoxy resin, an unsaturated polyester resin, an acrylic resin, a vinyl ester resin, a phenol resin, and a benzoxazine resin. Among these, an epoxy resin is preferable because the strength after curing can be increased.
The prepreg may contain various additives such as a curing agent, a release agent, a defoaming agent, an ultraviolet absorber, and a filler.

(Cut the prepreg into the shape determined by the shape analysis software)
As a method of cutting the prepreg, it is preferable to cut based on CAD data of the planar shape 9 using a cutting plotter. At that time, it is preferable that the tension application positions 5B, 5C, 6B, 6C, 7B (2 places), 7C (2 places), 8B, and 8C marked at the time of CAD data generation are made clear ( FIG. 5).
(Lamination of cut prepreg)
Next, the cut prepregs are laminated so as to have a desired configuration and number, thereby producing a laminate. The laminated structure of the prepreg used in the method for producing a preform of the present invention may be a unidirectional lamination, an orthogonal lamination, or a pseudo isotropic lamination, but if the prepreg is a UD prepreg, the prepreg is torn during shaping. It is preferable to form an orthogonal laminate from the viewpoint of shear deformation.

  The number of prepregs laminated is preferably 2 to 30. If the number of prepregs laminated is 2 or more, a molded product having sufficient strength can be obtained, and if it is 30 or less, the cost of lamination can be suppressed. When the prepreg is a woven prepreg, one prepreg can be handled as a laminate.

Next, as shown in FIG. 6, the laminated body 30 is arrange | positioned at preform type | mold (female type | mold 10 and male type | mold 20).
(Preform type)
The preform mold in this embodiment can be of any type and material as long as the laminate 30 can be shaped into a desired shape when the prepreg laminate is clamped by the mold. Even if it exists, it can use for the manufacturing method of the preform of this invention.

In FIG. 7, the female mold 10 is used for the upper mold and the male mold 20 is used for the lower mold, but these may be reversed, and either may be movable.
The preform type material is not particularly limited as long as it can shape a prepreg such as metal or chemical wood, but is preferably chemical wood because the material is inexpensive and easy to process. .

Next, as shown in FIGS. 7A and 7B, the locations 5B, 5C, 6B, 6C, 7B (2 locations), 7C (2 locations), 8B, and 8C of the laminate 30 specified by the simulation are used as the tension applying means 40. Then, as shown in FIG. 8, the laminate 30 is heated by the heater 50 and then tension is applied.
(Tensioning means)
The tension applying means 40 includes a clamp 41 that chucks a necessary portion of the prepreg laminate, a tension applying mechanism 42 that applies tension in a direction substantially perpendicular to the male and female narrow pressure directions, and a chuck position that moves in the narrow pressure direction. It is preferable to have a movable position mechanism 43.

  The material of the clamp 41 is not particularly limited as long as it does not deform at the preform temperature and can sufficiently chuck the prepreg heated and softened, but it is a plastic product from the viewpoint of workability and availability. It is preferable.

  Examples of the clamping method include a spring type and an air cylinder type, but an air cylinder type is preferable because the clamping force is easily increased.

  After the laminated body 30 is chucked by the clamp 41, it is desirable to apply a tension in a direction substantially perpendicular to the narrow pressure direction of the male and female dies by the tension applying mechanism.

  Examples of a method for applying tension include an air cylinder method and a winding spring method, but the winding spring method is desirable because it can move smoothly when a load is applied. Moreover, as tension | tensile_strength provided to the laminated body 30 by the tension | tensile_strength provision mechanism 42, it is preferable that it is 1-50N.

  The tension applied to the prepreg laminate by the tension applying mechanism 42 is substantially perpendicular to the male-female narrow pressure direction and is biased to the fiber direction of the prepreg. This is preferable because wrinkles can be effectively avoided with a small load.

  Specifically, for example, tension is applied to the tension applying positions 8B and 8C shown in FIG. 7B in the diagonally downward direction in the drawing using the clamp 41, and this is in the portion 8A in FIG. 2A. The mesh (unit structure of the woven fabric) is determined by the shaping simulation so as to coincide with the extending direction.

  It is desirable to apply tension after heating the laminated body 30 to a predetermined temperature while being clamped, and to move the chuck position in the narrow pressure direction of the mold by the position movable mechanism 43.

  Examples of the movable system include an air cylinder system and a coil spring system, but the coil spring system is desirable because it can move smoothly when subjected to a load in the narrow pressure direction of the mold (vertical direction in general equipment). . In FIG. 7A, a winding spring is even arranged to support the weight of the tension applying means 40 so that the chuck position moves in accordance with the load received from the laminate 30 when the mold is narrowed.

(Heating machine)
The heater 50 heats the laminated body 30 before softening. Examples of the heating method include a hot air type and an infrared type, but an infrared type is preferable because the heating time can be shortened.
Moreover, this heating machine 50 is located in the upper part of the laminated body 30 only when it heats, and is located in the place so that it may not interfere with the operation | movement of the female die 10 at the time other than that.

  Moreover, it is preferable that the heating temperature of the laminated body 30 is 40-80 degreeC. If the heating temperature is 40 ° C. or higher, it can be easily formed into a predetermined preform shape, and if it is 80 ° C. or lower, curing of the thermosetting resin during the manufacture of the preform can be avoided.

  Thereafter, as shown in FIG. 9, the female mold 10 is lowered, and the laminated body 30 is shaped by clamping the laminated body 30 between the male mold 20 and the female mold 10. At that time, the prepreg is pulled in accordance with the narrow pressure of the mold while the tension applying mechanism 42 applies an appropriate tension in the bias direction in a direction substantially perpendicular to the narrow pressure direction of the male and female dies. Further, the position of the chuck is moved by the position moving mechanism 43 according to the narrow pressure of the mold.

  Moreover, it is preferable that the pressure at the time of clamping is 0.01-0.1 MPa. If the pressure is 0.01 MPa or more, it can be easily formed into a predetermined preform shape, and if it is 0.1 MPa or less, the preform manufacturing apparatus can be simplified.

  Next, as shown in FIG. 10, after the tension is gradually applied and the clamp 41 is removed, the female mold 10 is raised, and the laminated body 30 shaped from the male mold 20 is taken out as shown in FIG. 11.

  In the preform manufacturing method described above, after the laminated body 30 is arranged in the preform mold (female mold 10 and male mold 20), the location of the prepreg specified by the simulation is chucked by the clamp 41 of the tension applying means 40. .

  Thereafter, after the laminated body 30 is heated by the heater 50, the tension is applied by the tension applying mechanism 42 in a direction substantially perpendicular to the narrow pressure direction of the male and female dies and in the bias direction. Finally, the position movable mechanism 43 allows the clamp position to be moved in the narrow pressure direction of the male and female molds, and then the preform mold is narrowed to shape the prepreg.

  In this way, a simulation is performed assuming that the fabric prepreg is shaped into a three-dimensional shape using the shape analysis software, and the location where the shear deformation angle of the fabric prepreg at the time of shaping is 15 ° or more is specified. By forming the prepreg while applying a tension in the bias direction to the fiber direction of the prepreg at that position, it becomes possible to efficiently avoid wrinkles generated in the preform.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the examples.
(Example 1)
In order to shape the bucket seat 1 of the automobile shown in FIG. 1, the shape of the bucket seat 1 is measured using an optical three-dimensional measuring instrument (manufactured by OTTO Vision Technology Gmbh, product name: kolibri move), and the measurement is performed. By inputting the data into 3D CAD software (manufactured by Siemens PLM Software, product name: NX), 3D CAD data of bucket seat 1 was obtained.

  Using the three-dimensional CAD data using formability analysis software (manufactured by Siemens PLM Software, product name: Fibersim), select “PPG-PL-3K” as the item “Material” in the software, and select the item “Fiber Spacing”. “factor” is input as “0.2”, the item “Net Productivity” is selected, and a desired simulation is performed. As shown in FIGS. 2A and 2B, the shear deformation angle distribution of the prepreg in the bucket seat 1 2 was obtained. (A shear deformation angle of 0 ° or more and less than 15 ° is shown as 2A, 15 ° or more and less than 30 ° is shown as 2B, and 30 ° or more is shown as 2C).

  After the simulation, the item “Generate Flat Pattern” was selected to obtain CAD data of the planar shape 9 two-dimensionally developed as shown in FIG. At that time, the positions 5A, 6A, 7A (two places) and 8A at which the shear deformation angle shown in FIG. 2A is 15 ° or more are marked using the “Markers” function, and the corresponding positions are shown in FIG. It was specified as 5B, 6B, 7B (2 places) and 8B shown. Further, the positions that are symmetrical with respect to the central axis of the planar shape 9 with respect to 5B, 6B, 7B (2 places), and 8B are specified as 5C, 6C, 7C (2 places), and 8C.

  Next, a prepreg sheet (manufactured by Mitsubishi Rayon Co., Ltd., product name: TR391E250S, thickness per sheet: 0.22 mm) prepared by impregnating the carbon fiber aligned in one direction with the epoxy resin composition was prepared.

  Using the cutting plotter, the prepreg sheet has the same shape as the planar shape 9 so that the arrow direction in FIG. 5 coincides with the orientation direction of the carbon fibers, that is, the orientation angle of the carbon fibers becomes 0 °. Three pieces were cut. Furthermore, two sheets were cut into the same shape as the planar shape 9 so that the arrow direction in FIG. 5 was orthogonal to the orientation direction of the carbon fibers, that is, the orientation angle of the carbon fibers was 90 °.

  This cut prepreg sheet was laminated so that the orientation direction of the carbon fibers was 0 ° / 90 ° / 0 ° / 90 ° / 0 °, and a laminate 30 was produced.

  Next, in the molding machine, as shown in FIG. 6, the female mold 10 is disposed as the movable mold on the upper mold, the male mold 20 is disposed on the lower mold as the fixed mold, and the laminate 30 is disposed on the male mold 20. did.

  Thereafter, as shown in FIG. 7A and FIG. 7B, the locations 5B, 5C, 6B, 6C, 7B (2 locations), 7C (2 locations) of the laminate 30 where the shear deformation angle specified in the simulation is 15 ° or more. ), 8B and 8C were chucked by the clamp 41 of the tension applying means 40.

  Thereafter, an infrared heater (heating machine 50) was placed on the upper part of the laminate 30, and the laminate 30 was heated to about 60 ° C. and softened (FIG. 8). Thereafter, tension was applied by the tension applying mechanism 42 in a direction substantially perpendicular to the male and female narrow pressure directions in the bias direction specified by the simulation. At this time, the tension of the winding spring installed in the tension applying mechanism 42 was set to 20N.

  Thereafter, after the position movable mechanism 43 allows the chuck position to be moved in the direction of narrowing the mold, the female mold 10 is lowered to narrow the male mold 20 and the female mold 10 as shown in FIG. Thus, the laminate 30 was shaped.

Thereafter, as shown in FIG. 10, the tension of the tension applying mechanism 42 is gradually applied and the clamp 41 is removed, and then the female mold 10 is raised, and the laminate 30 is removed from the male mold 20 as shown in FIG. Typed. The delaminated laminate 30 was shaped into a desired shape without wrinkles.
The preform was placed in a lower mold for compression molding heated to 140 ° C., held between the upper mold for 10 minutes, and heated and pressurized to obtain a fiber reinforced resin molded product. The obtained molded product was excellent in strength and appearance.
(Comparative Example 1)
5B, 5C, 6B, 6C, 7B (2 places), 7C (2 places), 8B, 8C specified in the simulation are not selected, and 10 places from the region where the shear deformation angle is 0 ° or more and less than 15 °. A preform was produced in the same manner as in Example 1 except that the tension was applied by selecting. The resulting preform was wrinkled frequently.

  Further, when this preform was compression-molded by the same method as in Example 1, the obtained molded product was not excellent in strength and appearance.

1 Bucket sheet 2 Shear deformation angle distribution 2A Shear deformation angle: 0 ° or more and less than 15 ° 2B Shear deformation angle: 15 ° or more and less than 30 ° 2C Shear deformation angle: 30 ° or more 3A 0 ° direction of UD prepreg (cross warp of prepreg) direction)
3B 90 ° direction of UD prepreg (weft direction of cross prepreg)
Angle of 0A direction and 90 ° direction of 4A UD prepreg (= 90 °)
4B Shear deformation angle 5A, 6A, 7A, 8A Position where shear deformation angle is 15 ° or more 5B, 5C, 6B, 6C, 7B, 7C, 8B, 8C Tension applying position 9 Planar shape 10 Female type 20 Male type 30 Laminate 40 Tension applying means 41 Clamp 42 Tension applying mechanism 43 Position movable mechanism 50 Heating machine

Claims (3)

Prior to the main molding to obtain a desired fiber-reinforced resin molded product, a method for producing a preform that is shaped into a predetermined shape by narrowing a sheet-like prepreg with a male and female mold,
A method for producing a preform, which is shaped while applying tension to a location of a prepreg in which the shear deformation angle of the woven fabric prepreg is 15 ° or more calculated by simulation using a shape analysis software.   The method for producing a preform according to claim 1, wherein tension is applied in a bias direction with respect to a fiber direction of the prepreg.   A method for producing a fiber-reinforced composite material molded article, wherein a preform produced by the method for producing a preform according to claim 1 or 2 is compression-molded with a molding die to obtain a fiber-reinforced composite material molded article having a three-dimensional shape.