JP2009000906A - Internal pressure molding method for fiber-reinforced resin structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To mold a fiber-reinforced resin structure having uniform physical properties, by closely attaching a bag to the inside of the fiber-reinforced resin structure, while uniforming the temperature in the bag which is placed in the inside of the fiber-reinforcement resin structure and into which a heat transfer medium is introduced. <P>SOLUTION: The molding method comprises introducing a heat transfer medium heated to a predetermined temperature into the bag 1 that is placed in the hollow fiber-reinforced resin structure 2 that is arranged in a mold. The heat transfer medium is introduced into the inside through the introducing inlet 5 of the bag, and the introduced heat transfer medium is discharged to the outside through the discharging outlet 6 of the bag 1 that is smaller in cross-section than the introducing inlet. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an internal pressure molding method for a fiber reinforced resin structure, and more particularly to an internal pressure molding method using a bag having an inlet and an outlet.

  Patent Document 1 relates to an internal pressure molding method. In the conventional technique, a heating medium such as heated air, hot water, water vapor, polyalkylene glycol, silicone oil or the like is introduced into the inside of the silicone bag by a molding method disclosed in Patent Document 1. Then, a structure is formed by bringing a molding material, for example, CFRP, into close contact with a mold (not shown). FIG. 2 is an explanatory view of such a conventional molding method, in which heated air is introduced into a silicone bag to pressurize the bag, and the CFRP structure is heated while closely contacting a mold (not shown). It shows what is to be cured.

  However, in the silicone bag 1 having the shape as shown in FIG. 2, the heated air 30 as a heating medium is injected and stays in the silicone bag 1, so that convection is generated inside the silicone bag 1 and the temperature is increased. There is a problem that the distribution becomes non-uniform, non-uniformity occurs in the degree of curing of the CFRP structure 2, and the desired physical properties cannot be obtained uniformly.

JP 2006-130875 A

  The present invention has been made in view of such circumstances, and its purpose is to equalize the temperature in the bag where the heat medium is introduced inside the fiber reinforced resin structure and to obtain a fiber reinforced resin with uniform physical properties. The object is to provide a method of forming a structure.

  In order to solve the above problems, the internal pressure molding method for a fiber reinforced resin structure according to the present invention is heated to a predetermined temperature inside a bag placed in a hollow fiber reinforced resin structure disposed in a mold. The bag is molded by applying an internal pressure by introducing a heated medium so that the bag is brought into close contact with the inside of the fiber reinforced resin structure, and the fiber reinforced resin structure is formed through the introduction port of the bag. The heating medium introduced into the body and introduced into the fiber reinforced resin structure is discharged to the outside through an outlet having a smaller cross-sectional area than the inlet of the bag. .

  In addition to the above features, the internal pressure molding method for a fiber-reinforced resin structure according to the present invention is characterized in that the bag is a silicone bag.

  In addition to the above features, the internal pressure molding method for a fiber reinforced resin structure of the present invention is characterized in that the heating medium discharged from the discharge port circulates to the introduction port.

  Further, the bag for internal pressure molding of the fiber reinforced resin structure of the present invention introduces a heating medium heated to a predetermined temperature into the bag placed inside the hollow fiber reinforced resin structure arranged in the mold. The bag is used in a method of forming the bag by applying an internal pressure so that the bag is brought into close contact with the inside of the fiber reinforced resin structure. The bag includes an inlet for the heating medium, and an inlet for the heating medium. It has a discharge port with a small cross-sectional area.

  In addition to the above characteristics, the bag for internal pressure molding of the fiber reinforced resin structure of the present invention is characterized in that the bag is a silicone bag.

  The present invention molds a fiber reinforced resin structure having uniform physical properties without variation in bending strength and the like by uniformly heating and curing the fiber reinforced resin structure from the inside with a uniform temperature distribution in the bag. be able to. The present invention also has the effect of shortening the molding operation.

  The best mode for carrying out the present invention is to provide a heating medium inlet and outlet in a pressurizing bag for pressurizing a fiber resin structure as a molding material, and to cut off the inlet from the sectional area of the outlet. By increasing the area and applying pressure in the bag and circulating the heating medium, the temperature in the pressure bag is made uniform.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is an explanatory diagram of a silicone bag having an inlet and an outlet according to the present embodiment and an internal pressure molding method using the same. The silicone bag 1 has an inlet 5 having a diameter of 30 mm and an outlet 6 having a diameter of 10 mm, and uses silicone oil 3 as a heating medium. Since this silicone oil is circulated by the oil pump 7, the inside of the silicone bag 1 is pressurized based on the difference in cross-sectional area between the inlet and outlet, and the CFRP structure 2 is molded (not shown). It is made to adhere to, and this is heated and hardened.

  As a structural material, a multi-axis CFRP material (± 45 °) was used, and vacuum press molding was performed in two stages of 60 minutes at a silicone oil temperature of 90 ° C. and 90 minutes at 130 ° C. Then, the degree of internal surface hardening and the bending strength of the CFRP structure were measured at each part A to C shown in FIG.

  As a comparative example, heated air 30 having an injection temperature of 130 ° C. is injected into a silicone bag 1 (see FIG. 2) having the same volume as the silicone bag shown in FIG. The strength was measured at the same site as the sites A to C shown in FIG.

  The results are shown in Table 1. The molding cycle in the table is one cycle, that is, the time required to mold one CFRP structure when the molding operation of the CFRP structure is repeated.

  The results shown in Table 1 show that in the comparative example, both the degree of internal surface hardening and the bending strength vary depending on the site, whereas in the examples of the present invention, the degree of internal surface hardening is high and the bending strength increases. It can be seen that uniform physical properties are obtained regardless of the part.

  In the above embodiment, a silicone bag is used as the bag. However, the bag according to the present invention is not limited to this, and may be made of ABS, acrylic, polyamide, urethane, synthetic rubber, or the like. .

FIG. 1 is an explanatory diagram of a silicone bag having an inlet and an outlet according to the present embodiment and an internal pressure molding method using the same. FIG. 2 is an explanatory view of a bag according to a conventional molding method and an internal pressure molding method using the bag.

Explanation of symbols

1 silicone bag,
2 CFRP structure,
3 Silicone oil (introduction side),
4 Silicone oil (discharge side),
5 introduction port,
6 outlet,
7 Oil pump,
30 heated air,
50 inlet

Claims (5)

The bag is placed inside the fiber reinforced resin structure by applying an internal pressure by introducing a heating medium heated to a predetermined temperature into the bag placed in the hollow fiber reinforced resin structure placed in the mold. A method of forming a film in close contact with
The heating medium is introduced into the fiber reinforced resin structure through the introduction port of the bag, and the heating medium introduced into the fiber reinforced resin structure has a cross-sectional area from the introduction port of the bag. An internal pressure molding method for a fiber reinforced resin structure, characterized in that the fiber reinforced resin structure is discharged to the outside through a small discharge port. The internal pressure molding method according to claim 1,
An internal pressure molding method of a fiber reinforced resin structure, wherein the bag is a silicone bag. The internal pressure molding method according to claim 1 or 2,
An internal pressure molding method of a fiber reinforced resin structure, wherein a heating medium discharged from the discharge port circulates to the introduction port. The bag is placed inside the fiber reinforced resin structure by applying an internal pressure by introducing a heating medium heated to a predetermined temperature into a bag placed inside the hollow fiber reinforced resin structure disposed in the mold. A bag used in a method of molding in close contact with
The bag for internal pressure molding of a fiber reinforced resin structure, wherein the bag has an inlet for the heating medium and an outlet having a smaller cross-sectional area than the inlet. The bag according to claim 4, wherein
A bag for internal pressure molding of a fiber reinforced resin structure, wherein the bag is a silicone bag.

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