JP2009028961A - Manufacturing method and manufacturing system of FRP molded body - Google Patents

Abstract

A method and system for manufacturing an FRP molded body having a desired fiber volume content by a filament winding method.
A method for manufacturing an FRP molded body includes a step (a) of impregnating a fiber bundle having conductivity with a thermosetting resin, and a fiber bundle while energizing a part of the fiber bundle impregnated with the resin. And (b) wrapping around the rotating member. In addition, the FRP molded body manufacturing system includes a resin impregnating unit 30 for impregnating a conductive fiber bundle with a thermosetting resin, a rotation driving unit 53 for rotationally driving a work 50, and a fiber bundle impregnated with a resin. A fiber bundle guide 40 that winds the fiber bundle F around the workpiece 50 by being guided in the direction of the workpiece 50, and a power supply device 60 that supplies current to a part of the length of the fiber bundle F are provided.
[Selection] Figure 1

Description

  The present invention relates to a method and a system for manufacturing an FRP (Fiber Reinforced Plastics) molded body by a filament winding method.

  In recent years, development of high-pressure hydrogen tanks used in fuel cell systems has been progressing. In particular, in an in-vehicle fuel cell system, a gas tank made of FRP is regarded as promising from the viewpoint of securing strength and reducing weight.

A gas tank made of FRP is generally manufactured by using a filament winding method (hereinafter referred to as “FW method”). In the FW method, fibers (for example, carbon fibers) impregnated with uncured (liquid or gel) thermosetting resin are wound around a rotating liner (inner container) by several to several tens of layers. Thus, a resin-impregnated fiber layer is formed, and the resin is thermoset by heating this layer. Thereby, the fiber reinforced plastic (FRP) layer which consists of a fiber and a thermosetting resin is formed.
Japanese Patent Laid-Open No. 3-161323 JP-A-5-84840

  By the way, in the FRP molded body produced by the FW method, the inner side, that is, the side closer to the liner (hereinafter referred to as “inner layer”) than the side relatively close to the outer surface (hereinafter referred to as “outer layer”) in the FRP layer. ”) Has a tendency to increase in fiber volume content (Vf). Here, the fiber volume content is the ratio of the fiber to the unit volume of the FRP layer. Hereinafter, the phenomenon in which the fiber volume content increases is also referred to as “high Vf”.

  The main cause of the high Vf is that as the winding of the resin-impregnated fiber is wound around the liner and the amount of lamination increases, the resin impregnated into the fiber oozes due to the tightening effect due to the tension applied to the resin-impregnated fiber. Can be mentioned. Also, the centrifugal force received during the FW process (resin-impregnated fiber winding process) makes it easier for the resin to bleed out toward the outside of the liner.

  Such a higher Vf of the inner layer becomes more significant as the working pressure of the gas tank becomes higher. This is because in order to give strength to the gas tank, it is necessary to increase the number of layers around which the resin-impregnated fiber is wound and to increase the thickness of the fiber-reinforced plastic layer. However, since the largest stress is applied to the inner layer in the gas tank, if Vf of the inner layer is too high, the fatigue endurance performance is significantly lowered, and the inner layer may be cracked. Therefore, a method for producing an FRP molded body that can obtain a desired Vf by suppressing the increase in the Vf of the inner layer is desired.

  However, for example, if the tension of the resin-impregnated fiber is reduced in order to suppress the seepage of the resin from the fiber, the strength of the tank is reduced. Alternatively, even if the viscosity of the resin is increased, the resin is less likely to permeate into the fibers, so that the strength of the tank is also lowered. Therefore, it is difficult to suppress the seepage of the resin while winding the resin-impregnated fiber.

On the other hand, since the curing temperature of the resin is generally as high as 100 ° C. or higher, facilities such as an electric furnace must be used. Therefore, in the manufacture of the current FRP molded body, after the FW process is completed, the liner or the like on which the resin-impregnated fiber layer is formed is moved to an electric furnace, and the resin thermosetting process is started. However, since this thermosetting process takes a long time (for example, 3 to 5 hours), the uncured resin may ooze out from the fiber during that time, and Vf may change.
Furthermore, due to this thermosetting step, there is a problem that it takes time to manufacture the FRP molded body.

  In order to shorten the manufacturing process, for example, a heater may be disposed around a liner or the like, and the FW process may be performed while heating the resin-impregnated fiber layer. However, it is not easy to sufficiently heat the resin-impregnated fiber layer in such an arrangement. In addition, since the resin-impregnated fibers are wound around the liner one after another during heating, it is still difficult to promote thermosetting.

As a related technique, Patent Document 1 discloses a method for molding a cylindrical structure in which resin-impregnated fibers are heated and cured while being wound around a tank. Patent Document 2 discloses a method for producing a fiber-reinforced plastic tube in which a resin is impregnated by energizing resin-impregnated carbon fibers wound around the tube.
However, neither of Patent Documents 1 and 2 describes any problems such as seepage of resin from the fibers and high Vf.

  Therefore, in view of the above problems, the first object of the present invention is to provide a method and system for producing an FRP molded body having a desired fiber volume content. Moreover, this invention makes it the 2nd objective to shorten the thermosetting process in manufacture of a FRP molded object.

In order to achieve the above object, a method for manufacturing an FRP molded body according to the first aspect of the present invention is a method for manufacturing an FRP molded body by a filament winding method. A step (a) of impregnating the resin, and a step (b) of winding the fiber around the rotating member while energizing a part of the length of the fiber impregnated with the resin.
Thus, since the fiber is wound around the rotating member while the fiber is heated by energization, the resin impregnated in the fiber can be quickly thermoset.

  Here, in the step (b), by energizing at least the fibers wound around the rotating member, the resin impregnated in the fibers can be quickly thermoset around the rotating member. Further, since the rotating member itself is heated by the heat generated by the fibers wound around the rotating member, the thermosetting of the resin around the rotating member is further promoted.

  In the step (b), the energization amount to the fiber may be controlled based on the tension of the fiber, the viscosity of the resin, or a desired fiber volume content. That is, without changing the fiber tension or resin material properties, the heat generation of the fiber and the temperature of the rotating member can be adjusted so that the desired fiber volume content can be obtained, and the resin can be thermoset at the desired speed. Can be made.

The method for producing an FRP molded product according to the second aspect of the present invention is a method for producing an FRP molded product by a filament winding method, wherein a conductive fiber is impregnated with a thermosetting resin ( a), a step (b) of forming a resin-impregnated fiber layer by winding the fiber impregnated with the resin around a rotating member, and a furnace for heating the resin-impregnated fiber layer while energizing the fiber And (c) a heating step.
In this way, in parallel with heating the resin-impregnated fiber layer from the outside in the heating furnace, by energizing the fiber to generate heat, it is possible to promote the thermosetting of the resin also from the inside of the resin-impregnated fiber layer. it can.

A manufacturing system for an FRP molded body according to a first aspect of the present invention is a system for manufacturing an FRP molded body by a filament winding method, and impregnates a thermosetting resin into a conductive fiber. A rotation drive unit that rotates the rotation member, a fiber guide that winds the fiber around the rotation member by guiding the fiber impregnated with the resin in the direction of the rotation member, and a length of the fiber And a power supply device that supplies current to a part of the direction.
Here, it is preferable that the power supply device supplies current to at least the fiber wound around the rotating member.

  Moreover, the manufacturing system of the said FRP molded object may further be equipped with the control part which controls the electric current or voltage supplied to the said fiber from the said power supply device. Accordingly, the resin can be thermally cured at a desired speed by adjusting the heat generation amount of the fiber and the temperature of the rotating member.

  The controller may control the current or voltage supplied to the fiber based on the viscosity of the resin or the desired fiber volume content. That is, the thermosetting speed of the resin impregnated in the fibers can be adjusted so that a desired fiber volume content can be obtained without changing the characteristics of the resin material.

  Further, the FRP molded body manufacturing system further includes a tension measuring unit that measures the tension of the fiber, and the control unit is configured to supply current or voltage to the fiber based on a measurement result of the tension measuring unit. May be controlled. That is, the thermosetting speed of the resin impregnated in the fiber can be adjusted so that a desired fiber volume content can be obtained without changing the tension of the fiber.

An FRP molded body manufacturing system according to a second aspect of the present invention is a system for manufacturing an FRP molded body by a filament winding method, and is formed around a heating furnace and a rotating member arranged in the heating furnace. And a power supply device for supplying current to the conductive fibers contained in the resin-impregnated fiber layer.
Thus, in parallel with heating the resin-impregnated fiber layer from the outside in the heating furnace, heat generation of the resin can be promoted also from the inside by supplying current to the fiber to generate heat.

  According to the present invention, the thermosetting speed of the resin can be easily controlled by adjusting the amount of current applied to the fiber, so that the design matters such as the characteristics of the resin material and the tension of the fiber are not changed. It becomes possible to produce an FRP molded body having a desired fiber volume content. Therefore, it is possible to manufacture a high-pressure gas tank made of FRP having sufficient strength and durability.

  In addition, according to the present invention, since the resin is heated from the inside of the resin-impregnated fiber layer by causing the fiber to generate heat, the time required for the thermosetting of the resin is shortened, and the fiber volume content changes during that time. Can be suppressed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same constituent elements are denoted by the same reference numerals, and the description thereof is omitted.
A method and system for manufacturing an FRP molded body according to a first embodiment of the present invention will be described with reference to FIG. The FRP molded body manufacturing system shown in FIG. 1 is a system in which a fiber reinforced plastic (FRP) layer is formed around a rotating member (workpiece) by a filament winding (FW) method. The measuring device 20, the resin impregnating unit 30, the fiber bundle guide (airo) 40, the work 50, the power supply device 60, and the control unit 70 are provided.

The fiber bundle supply unit 10 includes a plurality (three in FIG. 1) of bobbins 11a to 11c around which the fiber bundles f1 to f3 are wound. As the fiber bundles f1 to f3, conductive fibers such as carbon fibers and metal fibers are used, and in this embodiment, untwisted multifilaments of carbon fibers are used. The multifilament has about 3000 to 96,000 filaments.
The fiber bundle supply unit 10 adjusts the tension of the fiber bundles f <b> 1 to f <b> 3 and sends it to the tension measuring device 20.

  The tension measuring device 20 measures the tension of the fiber bundles f <b> 1 to f <b> 3 and outputs the measurement result to the control unit 70.

  The resin impregnation unit 30 includes a resin tank 31 in which a thermosetting resin in an uncured state (liquid or gel) is stored, and an impregnation roller 32 that guides the fiber bundles f1 to f3 to a predetermined position of the resin tank 31. To 34, the fiber bundles f1 to f3 are impregnated with the resin in the resin tank 31. As the thermosetting resin, an epoxy resin, a modified epoxy resin, an unsaturated polyester resin, or the like is used.

  The fiber bundle guide 40 forms a fiber bundle F by bundling the fiber bundles f <b> 1 to f <b> 3 impregnated with resin into one, and guides this to the workpiece 50. The fiber bundle guide 40 can be reciprocated in the longitudinal direction of the workpiece 50 and the direction perpendicular thereto, and is installed in a rotatable state so that the angle with respect to the workpiece 50 can be changed.

  The work 50 is, for example, a rotating body-shaped mold (mandrel) such as a cylinder, an inner container (liner) or the like in the case of manufacturing a tank, and is formed of metal or a hard resin such as polyethylene resin or polypropylene resin. . FIG. 1 shows a liner for a high-pressure gas tank.

The workpiece 50 is attached to the rotation drive unit 53 via the support unit 52 so as to be rotatable about its axis. The rotation drive unit 53 has a variable speed motor, and the work 50 is rotationally driven by this motor. By synchronizing the rotational motion of the workpiece 50 and the reciprocating motion of the fiber bundle guide 40, the fiber bundle F is wound around the workpiece 50 in a predetermined pattern. Thereby, the resin-impregnated fiber layer 51 is formed around the workpiece 50. The winding method (pattern) of the fiber bundle F is not particularly limited, and may be, for example, hoop winding, helical winding, or a combination of them.
The pressurizing pump 54 pressurizes the inside of the work 50 in order to prevent the work 50 from being recessed during the formation of the resin-impregnated fiber layer 51.

One terminal (for example, plus) of the power supply device 60 is electrically connected to the end portion (start of winding) of the fiber bundle F via the conducting wire 61 and the clip 62, and the other terminal (for example, minus) is The fiber bundle F supplied to the workpiece 50 is electrically connected via the conductor 63 and the fiber bundle guide 40. The power supply device 60 causes the fiber bundle F to generate heat by supplying a current to a closed circuit formed by the conductor 61 to the fiber bundle F to the conductor 63.
Since the fiber bundle supply unit 10 to the resin impregnated unit 30 are electrically insulated, the fiber bundle F before being supplied to the fiber bundle guide 40 is not energized.

  The control unit 70 includes a program for controlling the operation of the FRP molded body manufacturing system. The controller 70 controls the amount of heat generated by the fiber bundle F by adjusting the current and / or voltage supplied from the power supply device 60 in accordance with this program, whereby the temperature of the workpiece 50 and the temperature of the workpiece 50 are wound around it. The thermosetting speed of the resin impregnated in the fiber bundle F is adjusted.

  The values of the current and voltage supplied from the power supply device 60 (that is, the energization amount) are determined in the control unit 70 by manufacturing parameters such as the tension of the fiber bundle F (measurement result of the tension measuring device 20) and the viscosity of the resin. It is determined based on the value of Vf to be performed. For example, when the fiber bundle F is increased or when a resin having a low viscosity is used, the resin is likely to exude from the fiber bundle F. Therefore, in this case, the energization amount to the fiber bundle F is increased so that the resin is quickly thermoset when the fiber bundle F is wound around the workpiece 50. Further, even when Vf is lowered, the energization amount is increased so that the resin is quickly thermoset. On the other hand, when Vf is increased, the amount of energization may be reduced in anticipation of resin seepage.

Next, an example of control of the power supply device 60 by the control unit 70 will be described with reference to FIG.
When a container such as a high-pressure gas tank is produced, a higher stress is generated on the inner side of the resin-impregnated fiber layer 51, so that the resin can easily ooze out from the fiber. Therefore, in the present embodiment, the resin is rapidly cured at the beginning of winding on the inner resin-impregnated fiber layer 51, that is, the work 50, thereby preventing the resin from exuding from the fiber as much as possible and realizing a predetermined Vf. To do.

First, the control unit 70 increases the heat value of the fiber bundle F by increasing the current value in the time zone (time t _{0 to} t _S ) at which the fiber bundle F is wound around the work 50, thereby increasing the heat generation amount of the fiber bundle F. Increase the temperature quickly. The calorific value (or current value) of the fiber bundle F is determined in consideration of the heat capacities of the workpiece 50 and the surrounding system. When the temperature of the workpiece 50 reaches the thermosetting temperature of the resin, the resin impregnated in the fiber bundle F is quickly thermoset when wound around the workpiece 50.

  Here, before the fiber bundle F is wound around the workpiece 50, the temperature of the fiber bundle F itself must be lower than the thermosetting temperature T in order to prevent the resin impregnated therein from being thermoset. On the other hand, if the resin is warmed to some extent by the heat generated by the fiber bundle F, when it is wound around the workpiece 50, it immediately reaches the thermosetting temperature T and is thermoset. Therefore, in particular, during the winding start time zone, the heat generation amount of the fiber bundle F is set so that the temperature of the workpiece 50 rises to a desired value as soon as possible within a range where the temperature of the fiber bundle F does not exceed the thermosetting temperature T. It is important to control (current value).

  When the temperature of the workpiece 50 reaches the thermosetting temperature T, the control unit 70 controls the amount of heat generated by the fiber bundle F so that the temperature is maintained. Here, when the heat-cured resin-impregnated fiber layer 51 is formed around the work 50 to some extent, the amount of the fiber bundle F serving as a heat source increases, whereas the heat radiation amount is due to the heat-cured resin. Since it decreases, the calorific value of the fiber bundle F per unit length can be small. Therefore, the control unit 70 reduces the current value supplied to the fiber bundle F and suppresses the heat generation amount.

  Furthermore, when the winding of the fiber bundle F around the workpiece 50 is completed, the control unit 70 stops supplying current to the fiber bundle F. Thereby, the temperature of the thermosetting resin-impregnated fiber layer 51 is lowered, and the FRP molded body (high pressure gas tank) is completed.

  Thereafter, the FRP compact may be further heated in a furnace. Thereby, even if the resin-impregnated fiber layer 51 has a partially uncured portion, it can be completely thermoset. Even in this case, since the resin-impregnated fiber layer 51 is generally thermoset, Vf does not change significantly.

Next, the manufacturing method and system of the FRP molded object which concerns on the 2nd Embodiment of this invention are demonstrated, referring FIG.
FIG. 3 is a schematic diagram showing a heating furnace 80 which is a part of the FRP molded body manufacturing system according to the present embodiment. Inside the heating furnace 80, a heater 81 and a holding portion 82 for holding the workpiece 50 on which the resin-impregnated fiber layer 51 is formed are provided. A power supply device 90 is installed outside the heating furnace 80. One terminal (for example, plus) of the power supply device 90 is electrically connected to one end (for example, the start of winding) of the fiber bundle F that forms the resin-impregnated fiber layer 51 through the conductor 91 and the clip 92. Has been. In addition, the other terminal (for example, minus) of the power supply device 90 is electrically connected to the other end (for example, the end of winding) of the fiber bundle F through the conducting wire 93 and the clip 94. The power supply device 90 supplies a current to a closed circuit including the conductive wires 91 to the clip 92, the fiber bundle F, the clip 94 to the conductive wire 93.

  In the present embodiment, the fiber bundle F impregnated with the thermosetting resin is wound around the workpiece 50 without energizing the fiber bundle F in the same manner as in the normal FW method. When the resin-impregnated fiber layer 51 is thermoset in the heating furnace 80, the fiber bundle F is energized to generate heat. Thereby, the resin-impregnated fiber layer 51 is heated not only from the outside but also from the inside thereof, so that the time required for thermosetting the resin can be shortened.

It is a schematic diagram which shows the structure of the manufacturing system of the FRP molded object which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the example of control of the power supply device by the control part shown in FIG. It is a schematic diagram which shows a part of structure of the manufacturing system of the FRP molded object which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

  f1 to f3, F ... fiber bundle, 20 ... tension measuring device, 30 ... resin impregnated part, 40 ... fiber bundle guide, 50 ... work, 51 ... resin impregnated fiber layer, 53 ... rotational drive part, 60, 90 ... power supply device , 70 ... control unit, 80 ... heating furnace

Claims (10)

A method for producing an FRP molded body by a filament winding method,
A step (a) of impregnating a fiber having conductivity with a thermosetting resin;
A step (b) of winding the fiber around a rotating member while energizing a portion of the fiber impregnated with the resin in the length direction;
The manufacturing method of a FRP molded object provided with.   The method for producing an FRP molded body according to claim 1, wherein the step (b) includes energizing at least the fibers wound around the rotating member.   The step (b) includes controlling the energization amount to the fiber based on the tension of the fiber, the viscosity of the resin, or a desired fiber volume content. Manufacturing method of FRP molded object. A method for producing an FRP molded body by a filament winding method,
A step (a) of impregnating a fiber having conductivity with a thermosetting resin;
A step (b) of forming a resin-impregnated fiber layer by winding the fiber impregnated with the resin around a rotating member;
(C) heating the resin-impregnated fiber layer in a heating furnace while energizing the fibers;
The manufacturing method of a FRP molded object provided with. A system for producing an FRP molded body by a filament winding method,
A resin-impregnated portion for impregnating a fiber having conductivity with a thermosetting resin;
A rotation drive unit for rotating the rotation member;
A fiber guide for winding the fiber around the rotating member by guiding the fiber impregnated with the resin in the direction of the rotating member;
A power supply for supplying a current to a part of the fiber in the longitudinal direction;
FRP molded body manufacturing system.   The said power supply device is a manufacturing system of the FRP molded object of Claim 5 which supplies an electric current to the fiber wound around the said rotation member at least.   The manufacturing system of the FRP molded object of Claim 5 or 6 further provided with the control part which controls the electric current or voltage supplied to the said fiber from the said power supply device.   The said control part is a manufacturing system of the FRP molded object of Claim 7 which controls the electric current or voltage supplied to the said fiber based on the viscosity of the said resin, or the fiber volume content rate desired. A tension measuring unit for measuring the tension of the fiber;
The said control part is a manufacturing system of the FRP molded object of Claim 7 or 8 which controls the electric current or voltage supplied to the said fiber based on the measurement result of the said tension | tensile_strength measurement part. A system for producing an FRP molded body by a filament winding method,
A heating furnace;
A power supply device for supplying current to conductive fibers contained in a resin-impregnated fiber layer formed around a rotating member disposed in the heating furnace;
FRP molded body manufacturing system.

Images