JP2010023364A - Method of manufacturing hollow product using fiber-reinforced material and manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for manufacturing a hollow product using a fiber-reinforced material. <P>SOLUTION: A method is to manufacture a hollow product using a fiber-reinforced material and includes the arrangement process to arrange a hollow fibrous base with a magnetic material 30 disposed in the hollow part, inside a molding die 20, the injection process to inject a matrix material inside the molding die 20 in such a state that a magnetic field is generated between the inner surface of the molding die 20 and the magnetic material 30, and the curing process to cure the matrix material inside the molding die 20 in such a state that the magnetic field is generated between the inner surface of the molding die 20 and the magnetic material 30. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for manufacturing a hollow product with a fiber reinforced material.

  Patent Document 1 discloses a method of manufacturing a hollow product using fiber reinforced plastic. In this manufacturing method, when a hollow fiber substrate formed of prepreg is heated and cured in a mold, the fiber substrate is inflated by inflating a bag disposed in the hollow part of the fiber substrate. Is pressed against.

JP 2003-31765 A

In the manufacturing method described in Patent Document 1, when the bag placed in the hollow portion of the fiber base is inflated, the way the bag is inflated is not always constant. That is, when a large number of products are repeatedly manufactured, the way the bag swells changes for each product, resulting in variations in the quality of the manufactured products. For this reason, it is difficult to reliably prevent an appearance abnormality due to insufficient pressing force and a lack of thickness due to excessive pressing force. In the manufacturing method using a bag, it is difficult to ensure reproducibility of manufacturing quality, and the defective product rate is relatively high.
The present invention solves the above problems. The present invention provides a technique for manufacturing a hollow product with a fiber reinforced material without using a bag as in the prior art.

  The present invention provides a production method for producing a hollow product with a fiber reinforced material. This manufacturing method includes an arrangement step in which a hollow fiber base material in which a magnetic body is arranged in a hollow portion is arranged in a mold, and a magnetic field is generated between the inner surface of the mold and the magnetic body. An injection process for injecting the matrix material into the mold, and a curing process for curing the matrix material in the mold in a state where a magnetic field is generated between the inner surface of the mold and the magnetic body.

In the manufacturing method described above, the fiber base material is pressed against the inner surface of the mold by a magnetic field generated between the inner surface of the mold and the magnetic body. Thereby, the fiber base material is firmly fixed to the inner surface of the mold. When the fiber base material is impregnated with the matrix material or when the matrix material impregnated with the fiber base material is cured, the fiber base material is prevented from moving or deforming.
According to this manufacturing method, it is possible to accurately manufacture a hollow product using a fiber reinforced material without using a conventional bag.

The manufacturing method described above preferably further includes a step of taking out the product from the mold in a state where the magnetic field between the inner surface of the mold and the magnetic body is demagnetized after the curing step.
When removing the product from the mold, if the magnetic field between the inner surface of the mold and the magnetic body is demagnetized, the molded product can be removed without being deformed or damaged.

  The magnetic material used in the above-described manufacturing method may be in the form of a sheet such as a metal sheet, or a large number of particles such as metal spheres may be used. In particular, when a sheet-like magnetic material is used, the fiber base material can be uniformly pressed against the inner surface of the mold.

The present invention is also embodied in a manufacturing apparatus for manufacturing a hollow product with a fiber reinforced material. This manufacturing apparatus generates a magnetic field between a magnetic body disposed in a hollow portion of a fiber base, a mold that houses the fiber base on which the magnetic body is disposed, and an inner surface of the mold and the magnetic body. Excitation means are provided.
According to this manufacturing apparatus, the fiber base material can be pressed against the inner surface of the mold by generating a magnetic field between the inner surface of the mold and the magnetic body. Thereby, the fiber base material can be firmly fixed to the inner surface of the mold. When the fiber base material is impregnated with the matrix material or when the matrix material impregnated with the fiber base material is cured, the fiber base material can be prevented from moving or deforming.

It is preferable that the excitation means described above can be switched between an excited state in which a magnetic field is generated between the inner surface of the mold and the magnetic body and a demagnetized state in which the magnetic field between the inner surface of the mold and the magnetic body is demagnetized.
According to this configuration, when the product is taken out from the mold, the molded product can be taken out without being deformed or damaged by demagnetizing the magnetic field between the inner surface of the mold and the magnetic body.

It is preferable that the excitation means described above can adjust the strength of the generated magnetic field.
According to this configuration, the strength of the pressing force that presses the fiber base against the inner surface of the mold can be adjusted as appropriate. Thereby, it is possible to appropriately adjust the amount of the matrix material impregnated, the thickness of the cured product, and the like.

  According to the present invention, since a bag serving as a core is not required, a hollow product can be manufactured with high accuracy. Thereby, a large number of products can be repeatedly manufactured with stable manufacturing quality.

First, preferred embodiments for carrying out the present invention will be listed.
(Form 1) It is preferable that the mold is provided with a magnet. This magnet may be a permanent magnet or an electromagnet.
When providing a permanent magnet in a shaping | molding die, it is preferable to provide so that the direction of a magnet can be changed. In this case, the excitation state and the demagnetization state can be switched by changing the direction of the permanent magnet. Moreover, when providing a permanent magnet in a shaping | molding die, it is also preferable to provide a permanent magnet with respect to a shaping | molding die so that attachment or detachment is possible. In this case, it is possible to switch between the excited state and the demagnetized state by attaching / detaching the permanent magnet to / from the mold.
On the other hand, when an electromagnet is provided in the mold, it is possible to switch between an excited state and a demagnetized state by switching energization / non-energization to the electromagnet. In addition, when an electromagnet is provided in the mold, it is possible to adjust the strength of the magnetic field generated in the excited state by adjusting the amount of current supplied to the electromagnet.
(Form 2) The mold may be formed of a magnetic material or a non-magnetic material. The material for forming the mold may be any material having magnetic permeability.
(Form 3) Carbon fiber, glass fiber, aramid fiber, etc. are employable as a reinforced fiber, for example.
(Form 4) As the matrix material, for example, a thermosetting resin such as an epoxy resin, a polyester resin, a phenol resin, or a polyimide resin can be used. Alternatively, a thermoplastic resin such as a PEEK (polyether ether ketone) resin, a PPS (polyphenylene sulfide) resin, a vinyl chloride resin, or a polycarbonate resin can also be used. Moreover, it is not limited to those resin materials, For example, a rubber material etc. can also be used.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of a manufacturing apparatus 10 according to the present embodiment. The manufacturing apparatus 10 is an apparatus for manufacturing a product 100 made of fiber reinforced plastic. The product 100 has a hollow shape having a hollow portion 100a.

As shown in FIG. 1, the manufacturing apparatus 10 includes a molding die 20 for molding a product 100 and an injection device 40 for injecting a matrix material 104 into the molding die 20.
The mold 20 includes an upper mold 22 and a lower mold 24. Each of the upper mold | type 22 and the lower mold | type 24 is formed with the metal material which has magnetic permeability. A molding cavity 26 for molding the product 100 is formed between the upper mold 22 and the lower mold 24.
An injection path 28 for the matrix material 104 is formed in the mold 20. The injection path 28 is a flow path for introducing the matrix material 104 supplied from the injection apparatus 40 into the molding cavity 26. Although not shown, a plurality of injection paths 28 are formed in the mold 20.
The injection device 40 can pressure-inject the matrix material 104 into the molding cavity 26 of the mold 20. The kind of the matrix material 104 to be injected is not particularly limited. For example, the matrix material 104 may be a thermosetting resin such as an epoxy resin, a polyester resin, a phenol resin, or a polyimide resin. Alternatively, a thermoplastic resin such as a PEEK (polyether ether ketone) resin, a PPS (polyphenylene sulfide) resin, a vinyl chloride resin, or a polycarbonate resin may be used. Furthermore, the material is not limited to a resin material, and may be a rubber material, for example.

In the manufacturing apparatus 10, a plurality of magnetic bodies 30 are prepared. The magnetic body 30 is a sheet material made of a magnetic material. The magnetic body 30 of the present embodiment is formed of a stainless steel sheet material having soft magnetism. As will be described in detail later, the magnetic body 30 is disposed in the hollow portion 102a of the fiber base material 102 formed into a hollow shape (see FIG. 3). In this embodiment, the sheet-like magnetic body 30 is attached to the inner surface of the fiber base material 102. The magnetic body 30 is divided into a plurality according to the inner surface shape of the fiber base material 102.
The magnetic body 30 does not necessarily have a sheet shape. As the magnetic body 30, for example, a large number of minute metal spheres may be arranged in the hollow portion 102 a of the fiber substrate 102.

  The upper mold 22 and the lower mold 24 of the mold 20 are provided with permanent magnets 32 and 34, respectively. The permanent magnets 32 and 34 are provided such that their directions can be changed. In the upper mold 22 and the lower mold 24 of the molding die 20, by changing the directions of the permanent magnets 32 and 34, an excited state in which the inner surface 26a of the molding cavity 26 is magnetized and a demagnetization in which the inner surface 26a of the molding cavity 26 is not magnetized. The state can be switched. In the excited state, an attracting magnetic field is generated between the inner surface 26 a of the molding cavity 26 and the magnetic body 30. Thereby, the product 100 (or the fiber base material 102) is pressed against the inner surface 26a of the molding cavity 26 and is firmly fixed to the molding die 20. On the other hand, in the demagnetized state, the magnetic field described above is demagnetized, and the product 100 (or the fiber base material 102) is released from being fixed to the mold 20. As described above, the upper mold 22 and the lower mold 24 of the mold 20 are provided with an excitation / demagnetization switching structure using the permanent magnets 32 and 34 as in the known magnet stand (or magnet base).

Next, a method for manufacturing the product 100 using the manufacturing apparatus 10 will be described. FIG. 2 is a flowchart showing a flow of a manufacturing method of the product 100 using the manufacturing apparatus 10. Hereinafter, the manufacturing method of the product 100 will be described in detail along the flowchart shown in FIG.
First, in step S12, the direction of the permanent magnets 32 and 34 is confirmed, and it is confirmed that the mold 20 is in a demagnetized state. By leaving the molding die 20 in a demagnetized state, the operation of placing the fiber base material 102 in the molding cavity 26 is facilitated in the next step S14.

Next, in step S14, as shown in FIG. 3, the fiber base material 102 molded into a hollow shape is placed in the molding cavity 26 of the molding die 20. At this time, the magnetic body 30 is disposed in the hollow portion 102 a of the fiber base material 102. The magnetic body 30 disposed in the hollow portion 102 a faces the inner surface 26 a of the molding cavity 26 through the fiber base material 102.
The fiber base material 102 is formed by laminating reinforcing fibers. The fiber base material 102 can be formed in, for example, the molding cavity 26 of the mold 20. That is, by stacking the fiber base material 102 on the inner surface 26 a of the molding cavity 26 and further stacking the magnetic body 30, the hollow fiber base material 102 including the magnetic body 30 can be formed. Alternatively, the fiber base material 102 may be formed using an external device or mold, and the magnetic material 30 may be disposed in the hollow portion 102 a, and then the fiber base material 102 may be disposed in the molding cavity 26.
Although the reinforced fiber used for the fiber base material 102 is not specifically limited, For example, it can be set as carbon fiber, glass fiber, an aramid fiber, etc. Further, the reinforcing fiber may be impregnated with an uncured resin in advance, such as a prepreg.

Next, in step S16, as shown in FIG. 4, the directions of the permanent magnets 32 and 34 are changed to switch to the excited state. Thereby, a magnetic field attracting between the inner surface 26 a of the molding cavity 26 and the magnetic body 30 is generated. The magnetic body 30 presses the fiber substrate 102 against the inner surface 26 a of the molding cavity 26 and fixes the fiber substrate 102 to the inner surface 26 a of the molding cavity 26.
Here, the molding die 20 may be provided with an electromagnet using an electromagnetic coil instead of the permanent magnets 32 and 34. In this case, switching to the excited state can be performed by starting energization of the electromagnetic coil. In addition, when the molding die 20 is provided with an electromagnet, the magnetic field to be generated can be adjusted by the value of the current supplied to the electromagnetic coil. That is, the pressing force of the fiber base material 102 by the magnetic body 30 can be adjusted.

  Next, in step S <b> 18, as shown in FIG. 5, the matrix material 104 is injected into the molding cavity 26 of the mold 20 by the injection device 40. Thereby, the fiber base material 102 in the molding cavity 26 is impregnated with the matrix material 104. Since the mold 20 is in an excited state, the fiber base material 102 is pressed against the inner surface 26 a of the molding cavity 26 by the magnetic body 30. Therefore, deformation of the fiber base material 102 due to the flow of the matrix material 104 is prevented. The fiber substrate 102 is impregnated with an appropriate amount of matrix material 104. As described above, various types of matrix material 104 can be used. Here, a thermosetting resin (eg, an epoxy resin) is used for the matrix material 104. Therefore, it is not necessary to heat the mold 20 when the matrix material 104 is injected. On the other hand, when a thermoplastic resin is used for the matrix material 104, the mold 20 is preferably heated when the matrix material 104 is injected.

  Next, in step S20, as shown in FIG. 6, the molding die 20 is placed in the heating furnace 50, and the matrix material 104 in the molding cavity 26 is heated and cured. Since the mold 20 is in an excited state, the fiber base material 102 and the matrix material 104 are pressed against the inner surface 26 a of the molding cavity 26 by the magnetic body 30. Thereby, the matrix material 104 is heat-cured in a shape along the inner surface 26 a of the molding cavity 26. The pressing force of the fiber base material 102 by the magnetic body 30 is stable without greatly changing even when the temperature rises during heat curing. When a thermoplastic resin is used for the matrix material 104, the matrix material 104 is cured by cooling the mold 20.

Next, in steps S22 and S24, as shown in FIG. 7, an operation of taking out the product 100 that has been molded by heat curing from the mold 20 is performed.
First, in step S22, before opening the mold 20, the direction of the permanent magnets 32 and 34 is changed, and the mold 20 is switched to a demagnetized state. As a result, the magnetic field between the inner surface 26a of the molding cavity 26 and the magnetic body 30 disappears, and the product 100 is released from being fixed to the molding die 20. In addition, when it replaces with the permanent magnets 32 and 34 and the electromagnet is provided in the shaping | molding die 20, the shaping | molding die 20 is switched to a demagnetization state by stopping the electricity supply to the electromagnetic coil.
Next, in step S <b> 24, the mold 20 is opened, and the product 100 is taken out from the molding cavity 26 of the mold 20. By leaving the mold 20 in a demagnetized state, the product 100 can be taken out smoothly without being deformed.
Finally, in step S26, as shown in FIG. 8, the unnecessary part 100b is cut out from the product 100, and the magnetic body 30 is taken out from the hollow part 100a of the product 100. Thus, the manufacture of the product 100 by the manufacturing apparatus 10 is completed. Thereafter, the product 100 is completed by performing necessary finishing operations on the product 100.

  As described above, according to the manufacturing apparatus 10 of the present embodiment, for example, the product 100 made of carbon fiber reinforced plastic (CFRP) can be accurately manufactured by the RTM (Resin Transfer Molding) method. Since magnetic force is used to fix the fiber base 102 to the mold 20, the pressing force applied to the mold 20 applied to the fiber base 102 is stabilized as compared with the conventional technique of fixing by the internal pressure of the bag. Thereby, individual differences (quality differences between products) hardly occur in the amount of the matrix material 104 impregnated into the fiber base material 102 and the surface properties of the product 100 after curing. A large number of products 100 can be manufactured with stable manufacturing quality.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
For example, the shape of the product 100 to be manufactured is not limited to the shape of the above-described embodiment, and the product 100 having various shapes can be manufactured. For example, the product 100 having the curved surface portion 100c shown in FIG. 9 and the product 100 having the acute angle portion 100d shown in FIG. 10 are also similar to the above-described embodiment by changing the shape of the molding cavity 26. Can be manufactured.
In the manufacturing apparatus 10 and the manufacturing method described above, the magnetic body 30 may be a magnetic body that has already been magnetized, such as a magnet sheet. In this case, it is not necessary to provide the permanent magnets 32 and 34 and the electromagnet in the mold 20, and the mold 20 may be formed of a magnetic material such as metal. Even in this case, the matrix material 104 can be injected into the molding cavity 26 while the magnetic field is generated between the inner surface 26a of the molding cavity 26 and the magnetic body 30, and the matrix material 104 can be cured.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

The figure which shows the structure of the manufacturing apparatus of an Example. The flowchart which shows the manufacturing method of the product by the manufacturing apparatus of an Example. The figure which shows the manufacture process of a product (step S12, S14). The figure which shows the manufacture process of a product (step S16). The figure which shows the manufacture process of a product (step S18). The figure which shows the manufacture process of a product (step S20). The figure which shows the manufacture process of a product (step S22, S24). The figure which shows the manufacture process of a product (step S26). The figure which shows a mode that the product which has a curve part is manufactured. The figure which shows a mode that the product which has an acute angle part is manufactured.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10: Manufacturing apparatus 20: Mold 26: Molding cavity 26a: Inner surface 28 of cavity 26: Injection path 30: Magnetic body 32, 34: Permanent magnet 40: Injection apparatus 100: Product 100a: Product hollow part 102: Fiber base material 102a: hollow part of fiber substrate 104: matrix material

Claims (6)

It is a manufacturing method for manufacturing a hollow product with a fiber reinforced material,
An arrangement step of arranging a hollow fiber substrate in which a magnetic body is arranged in a hollow portion in a mold,
An injection step of injecting a matrix material into the mold in a state where a magnetic field is generated between the inner surface of the mold and the magnetic body;
A curing step of curing the matrix material in the mold in a state where a magnetic field is generated between the inner surface of the mold and the magnetic body;
A manufacturing method comprising:   The manufacturing method according to claim 1, further comprising a step of taking out the product from the molding die in a state where the magnetic field between the inner surface of the molding die and the magnetic body is demagnetized after the curing step.   The manufacturing method according to claim 1, wherein the magnetic body has a sheet shape. It is a production device for producing hollow products with fiber reinforced materials,
A mold in which a hollow fiber substrate is disposed;
A magnetic body disposed in a hollow portion of the fiber base;
Excitation means for generating a magnetic field between the inner surface of the mold and the magnetic material;
A manufacturing apparatus comprising:   The excitation means can switch between an excited state in which a magnetic field is generated between the inner surface of the mold and a magnetic body and a demagnetized state in which the magnetic field between the inner surface of the mold and the magnetic body is demagnetized. The manufacturing apparatus according to claim 4.   The manufacturing apparatus according to claim 4, wherein the excitation unit is capable of adjusting a strength of a generated magnetic field.

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