JP2014172305A - Heating method of fiber containing resin body and heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating method of a fiber containing resin body which improves heating efficiency of the fiber containing resin body without affecting the orientation of a reinforcement fiber in the fiber containing resin body, and to provide a heater of the fiber containing resin body.SOLUTION: A heater 10 of a sheet body 1 includes an infrared heater which heats the sheet body 1 for melting the sheet body 1 and further includes an infrared ray transmission plate 25 which restricts the sheet body 1 from expanding in a thickness direction during heating and holds a shape of the sheet body 1.

Description

  The present invention relates to a heating method and a heating apparatus for heating a fiber-containing resin body.

In general, a large number of fiber-containing resin bodies in which reinforcing fibers are dispersed in a matrix thermoplastic resin are used in automobile-related parts such as a front bulkhead of a vehicle. This type of fiber-containing resin body is formed, for example, into a sheet-like form (referred to as a sheet body) as a preformed body before being formed into a final product shape. Next, the sheet body is heated to undergo a preheating step in which the sheet body is melted, and a predetermined molding process is performed on the melted sheet body to form a final product shape.
In the fiber-containing resin body, internal stress is generated when the reinforcing fiber is dispersed (impregnated) in the thermoplastic resin. For this reason, in the preheating step, when the fiber-containing resin body is melted, the internal stress is released, so that the fiber-containing resin body becomes larger in the thickness direction, for example, and an air layer (heat insulating layer) is formed in the fiber-containing resin body. ) Occurs. Therefore, the problem that the heating efficiency of the fiber-containing resin body is reduced due to the air layer inhibiting heating has occurred.
In order to solve this problem, conventionally, in the preheating step, a device including a roll-type pressurizing device that reduces the fiber-containing resin body expanded during heating has been proposed (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 04-045905

  However, in the conventional technology, since the fiber-containing resin body is reduced in the thickness direction by reducing the fiber-containing resin body expanded in the middle of heating with a roll-type pressure device, the fiber-containing resin body is being heated. Expansion is unavoidable, leading to a decrease in heating efficiency associated with expansion. Furthermore, when the fiber-containing resin body that has been expanded once is squeezed, the orientation of the reinforcing fibers inside the fiber-containing resin body changes, which may affect the strength of the final molded product.

  In view of the above-mentioned problems of the prior art, the present invention is a method for heating a fiber-containing resin body in which the heating efficiency of the fiber-containing resin body is improved without affecting the orientation of reinforcing fibers inside the fiber-containing resin body. It is an object to provide a method and a heating device for a fiber-containing resin body.

  In order to solve the above problems, the present invention provides a heating method of a fiber-containing resin body that heats the fiber-containing resin body, and controls the expansion during heating and heats the fiber-containing resin body while maintaining the shape. Features.

  According to this configuration, since the heating is controlled while maintaining the shape of the fiber-containing resin body while restricting expansion during heating, the formation of an air layer in the fiber-containing resin body is prevented, thereby The heating efficiency of the resin body can be improved, and the fiber-containing resin body can be heated in a short time. Moreover, the change in the orientation of the reinforcing fibers inside the fiber-containing resin body can be prevented by regulating the expansion during heating.

  In this configuration, when the fiber-containing resin body is held by the shape holding means that transmits a predetermined wavelength, the fiber-containing resin body is heated by a non-contact type heating means that irradiates the predetermined wavelength. good. The predetermined wavelength may be an infrared wavelength. Moreover, you may heat the said surface of the said fiber containing resin body by vibrating the said shape holding means in the state which contacted the surface of the said fiber containing resin body.

  Further, the present invention provides a heating apparatus for a fiber-containing resin body provided with a heating means for heating the fiber-containing resin body, and includes a shape holding means for regulating expansion during heating and holding the shape of the fiber-containing resin body. It is characterized by that.

  According to this configuration, since the shape holding means for restricting the expansion at the time of heating and holding the shape of the fiber-containing resin body is provided, it is prevented that an air layer is formed in the fiber-containing resin body, The heating efficiency of the fiber-containing resin body can be improved, and the fiber-containing resin body can be heated in a short time. In addition, the shape holding means regulates the expansion during heating, so that the change in the orientation of the reinforcing fibers inside the fiber-containing resin body can be prevented.

  In this configuration, the heating unit is a non-contact type heating unit that irradiates a predetermined wavelength, the shape holding unit has a function of transmitting the predetermined wavelength, and the shape holding unit is the fiber-containing resin body. The fiber-containing resin body may be heated by the heating means while holding And a vibration means for vibrating the shape holding means in a state where the shape holding means and the surface of the fiber-containing resin body are in contact with each other, and heating the surface of the fiber-containing resin body with frictional heat caused by the vibration. May be.

  According to the present invention, since the heating is controlled while maintaining the shape of the fiber-containing resin body while restricting the expansion during heating, the formation of an air layer in the fiber-containing resin body is prevented, thereby The heating efficiency of the resin body can be improved, and the fiber-containing resin body can be heated in a short time. Moreover, the change in the orientation of the reinforcing fibers inside the fiber-containing resin body can be prevented by regulating the expansion during heating.

It is a schematic block diagram of the heating apparatus concerning this embodiment. It is a figure which shows the heating procedure of a heating apparatus, (A) is a figure which shows the state by which the sheet body was conveyed to the heating apparatus, (B) is a figure which shows the state which is heating the sheet body. (A) shows a state when the heating of the sheet body is completed, and (B) is a diagram showing a state when the heated sheet body is formed into a final product shape. It is a graph which shows the change of the surface temperature at the time of heating a sheet | seat body, and center temperature. It is a schematic block diagram of the heating apparatus concerning another embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a heating device according to the present embodiment.
The heating device 10 is a device for heating and melting (softening) a fiber-containing resin body (hereinafter referred to as a sheet body 1) formed in a sheet shape. The sheet body 1 is also called FRP (Fiber Reinforced Plastics) in which reinforcing fibers (reinforcing fibers (for example, carbon fibers)) are dispersed in a thermoplastic resin (for example, nylon 6, 6, etc.) that is a matrix. ).
As shown in FIG. 1, the heating device 10 is disposed to face the first heating unit 13 with the first heating unit 13 disposed on the floor surface 100 via the base plate 11 and the sheet body 1 interposed therebetween. A second heating unit 15. The second heating unit 15 is attached to the support frame 101 (or the ceiling surface) arranged substantially parallel to the base plate 11 via the lifting device 17, and the second heating unit 15 is operated by operating the lifting device 17. It moves so as to be able to contact and separate with respect to the first heating unit 13.

The first heating unit 13 includes a hollow housing 21 whose upper surface is open, and an infrared heater (heating means) 23 for irradiating the sheet body 1 with infrared rays is disposed inside the housing 21. . The infrared heater 23 includes a heating element such as a ceramic having a relatively low temperature (500 ° C. to 1000 ° C.), and uses far-infrared light (wavelength: 1 to 15 μm) emitted from the heating element.
The infrared heater 23 is desirably formed larger than the sheet body 1 in order to uniformly irradiate the entire sheet body 1 with infrared rays, but a plurality of infrared heaters are arranged side by side as long as uniform irradiation is possible. It is good also as a structure.
Further, as the infrared heater, for example, an infrared irradiation lamp or a halogen lamp can be used. The halogen lamp uses near infrared light (wavelength: 0.5 to 3 μm) emitted from a high-temperature (2000 ° C. to 2800 ° C.) heating element. Since the light emitted from the halogen lamp generally includes visible light, it is desirable to reduce the visible light by coloring the glass surface of the lamp or setting the heating element temperature to about 2000 ° C. or lower.

An infrared transmission plate (shape holding means) 25 that transmits infrared rays emitted from the infrared heater 23 is provided in the upper surface opening of the housing 21. The infrared transmission plate 25 is obtained by applying an infrared transmission treatment (for example, a surface treatment with a germanium compound or a silicon compound) to the surface of a glass plate having a certain degree of strength. Thereby, since the absorption of the infrared rays in the infrared transmitting plate 25 can be suppressed, the amount of infrared rays contributing to the heating of the sheet body 1 can be increased correspondingly, and the heating efficiency can be improved.
The infrared transmitting plate 25 has a function of supporting the sheet body 1 as well as a function of transmitting the infrared light irradiated from the infrared heater 23. Therefore, the infrared transmission plate 25 is formed to be at least larger than the sheet body 1, and the entire sheet body 1 can be supported by the infrared transmission plate 25. In addition, the surface of the infrared transmission plate 25 is formed in a flat surface and prevents visible irregularities from occurring on the sheet body 1 melted on the infrared transmission plate 25.
The distance between the infrared transmitting plate 25 and the infrared heater 23 is set to an optimum value when the infrared rays irradiated from the infrared heater 23 heat the sheet body 1.

The second heating unit 15 has substantially the same configuration as the first heating unit 13, and an infrared transmission plate 25 is disposed in an opening provided on a surface facing the first heating unit 13 (the lower surface of the housing). For this reason, the same code | symbol is attached | subjected about the structure same as the structure of the 1st heating part 13, and description is abbreviate | omitted.
A lifting device 17 is provided on the upper surface of the casing 21 of the second heating unit 15, and the lifting device 17 is fixed to the support frame 101 described above. The elevating device 17 is a device that elevates and lowers the second heating unit 15, and for example, a hydraulic device such as a hydraulic cylinder is used.
The elevating device 17 is configured to be able to descend the second heating unit 15 to a position where the gap between the second heating unit 15 and the first heating unit 13 is a predetermined interval. In the present embodiment, the first heating unit The gaps between the infrared transmission plates 25 of the 13 and the second heating unit 15 are set at substantially the same distance as the thickness of the sheet body 1 before heating. For this reason, by lowering the second heating unit 15, the sheet body 1 is sandwiched between the infrared transmission plates 25 of the first heating unit 13 and the second heating unit 15. In this state, by irradiating the sheet body 1 with infrared rays from the infrared heater 23, the sheet body 1 is heated while its expansion in the thickness direction is regulated.

  As shown in FIG. 1, the heating apparatus 10 includes a first conveyor 31 that conveys the sheet body 1 to the heating apparatus 10, and a second conveyor that conveys the sheet body 1 heated by the heating apparatus 10 to the next process. A conveyance conveyor 32 is provided. The transport surfaces of the first transport conveyor 31 and the second transport conveyor 32 are set to be substantially the same as the upper surface of the infrared transmission plate 25 of the first heating unit 13. Further, although not shown in the present embodiment, auxiliary conveying means for arranging the sheet body 1 conveyed from the first conveying conveyor 31 at a predetermined position on the infrared transmission plate 25 of the first heating unit 13 is provided. Yes. For example, the auxiliary conveyance means is configured to include a robot arm, and performs an auxiliary operation of grasping the end of the heated sheet 1 and conveying it onto the second conveyance conveyor 32.

Next, the heating procedure in the heating apparatus 10 will be described.
This heating procedure is performed as a pre-process for forming the sheet body 1 into a final product shape, and is a preheating process for melting the sheet body 1.
FIG. 2A shows a state in which the sheet body 1 is conveyed to the heating device 10 in the preliminary heating step, and FIG. 2B shows a state in which the sheet body 1 is heated. 3A shows a state when the heating of the sheet body 1 is completed, and FIG. 3B shows a state when the heated sheet body 1 is formed into a final product shape. It is.

In the preliminary heating step, the sheet body 1 is transported to the heating device 10 by the first transport conveyor 31 (FIG. 1). Specifically, as illustrated in FIG. 2A, the sheet body 1 is disposed at a substantially central portion on the infrared transmission plate 25 of the first heating unit 13. At this time, the infrared heaters 23 of the first heating unit 13 and the second heating unit 15 are energized to start heating.
Subsequently, as shown in FIG. 2B, the second heating unit 15 is lowered toward the first heating unit 13. Accordingly, the sheet body 1 is sandwiched between the infrared transmission plates 25 of the first heating unit 13 and the second heating unit 15. The gap H between the infrared transmission plates 25 when the second heating unit 15 is lowered is set to be approximately the same as the thickness H of the sheet body 1 before heating. For this reason, even if the sheet | seat body 1 clamped by each infrared rays transmissive board 25 is heated by the infrared heater 23, a shape is hold | maintained in the state by which the expansion | swelling to the thickness direction was controlled.

In this embodiment, since the infrared heater 23 is used as a heating unit, the temperature can be raised from the inside of the sheet body 1. When the inside of the sheet body 1 reaches a predetermined target temperature, the second heating unit 15 is raised as shown in FIG. In this embodiment, since heating is performed while restricting expansion of the sheet body 1 in the thickness direction, the thickness H of the sheet body 1 after heating can be kept substantially the same as before heating. Next, using an auxiliary conveyance means (not shown), the end of the sheet 1 melted by heating is grasped or hooked and moved to the second conveyance conveyor 32 (FIG. 1) for conveyance to the next process. .
Then, as shown in FIG. 3 (B), the melted sheet body 1 is conveyed to the press molding machine 40 and pressed in a state of being sandwiched between the upper mold 41 and the lower mold 42 of the press molding machine 40. Thus, a final product shape is formed.

Next, the operation of the above heating procedure will be described.
FIG. 4 is a graph showing changes in the surface temperature and the center temperature when the sheet body 1 is heated. FIG. 4 also shows a graph showing changes in the surface temperature and the center temperature when expansion in the thickness direction of the sheet body is not regulated as a conventional heating method of the sheet body.

In the case of preheating, heating is performed until the center temperature of the sheet body 1 reaches a predetermined target temperature. In the sheet body 1, internal stress is generated when carbon fibers are dispersed in the thermoplastic resin as a matrix. In the conventional heating method, since the expansion in the thickness direction of the sheet body is not regulated, the internal stress is released when the sheet body melts, so that the sheet body becomes larger in the thickness direction, and an air layer ( Heat insulation layer).
When an air layer is generated in the sheet body, the heating in the sheet body is inhibited by the air layer, and as shown in FIG. 4, until the center temperature rises to the target temperature as compared with the surface temperature of the sheet body. It took time to reduce the heating efficiency.
Further, in the conventional heating method, there is a concern about deterioration of the sheet body material due to excessive increase in the surface temperature of the sheet body. Furthermore, in the conventional heating method, the sheet body once expanded is reduced to the original thickness, and therefore, the orientation of the carbon fibers inside the sheet body changes during the reduction, which may affect the strength of the final molded product. . Furthermore, in the conventional heating method, since the heating time is excessive, there is a concern that the resin material of the sheet body is deteriorated due to excessive increase in the surface temperature.

On the other hand, in this embodiment, since the sheet body 1 is sandwiched by the infrared transmission plate 25 and heated in a state in which expansion in the thickness direction is restricted, an air layer may be generated in the sheet body 1. Is prevented. For this reason, as shown in FIG. 4, the surface temperature and the center temperature of the sheet body 1 are each raised to the target temperature in a short time, whereby the heating time in the preheating step can be shortened. Thereby, the improvement of heating efficiency can be aimed at without the possibility that the resin material of the sheet body 1 will deteriorate.
Furthermore, the change in the orientation of the carbon fibers inside the sheet body 1 can be prevented by regulating the expansion in the thickness direction during heating.

  Here, as a configuration for holding the sheet body 1, for example, a wire conveyor is assumed. However, in a wire conveyor, a mesh-like unevenness is generated on the surface of the sheet body 1 due to expansion during heating, which is not sufficient from the viewpoint of the design properties of the product. Furthermore, when infrared rays are irradiated from below the wire conveyor by an infrared heater, the gaps between the wires are subjected to non-contact heating by infrared rays, while the contact portions with the wires are heated by infrared rays. Therefore, it becomes contact heating by the heated wire. For this reason, it becomes difficult to heat the surface of the sheet body 1 uniformly, and the heating efficiency of the sheet body 1 is reduced.

  In contrast, in the present embodiment. Since the sheet body 1 is larger than the sheet body 1 and is sandwiched between the infrared transmission plates 25 which are glass plates having a smooth surface, the sheet body 1 is obtained even when the sheet body 1 is melted. It is possible to prevent unevenness due to the infrared transmitting plate 25 from being generated on the surface of the sheet, and to improve the design of the product after final molding. Furthermore, since the infrared rays irradiated from the infrared heater 23 pass through the infrared transmission plate 25 and are irradiated almost uniformly onto the surface of the sheet body 1, the heating efficiency of the sheet body 1 can be further improved.

Next, another embodiment will be described.
FIG. 5 is a schematic configuration diagram of a heating device 120 according to another embodiment.
The heating device 120 includes a first heating unit 113 disposed on the floor 100 via the base plate 11, and a second heating unit 115 disposed opposite to the first heating unit 113 with the sheet body 1 interposed therebetween. Is provided. The second heating unit 115 is attached to the support frame 101 (or the ceiling surface) disposed substantially parallel to the base plate 11 via the lifting device 17, and the second heating unit 115 is operated by operating the lifting device 17. It moves so as to be able to contact and separate from the first heating unit 113.

The first heating unit 113 includes a holding frame 121 having an open top surface that is disposed outside the casing 21 described above, and the casing 21 is mounted on a spring (elastic member) 123 that is disposed on the bottom surface 121 </ b> A of the holding frame 121. It becomes the composition arranged. Further, a housing side electromagnetic coil (vibration means) 125 is provided on the outer side surface 21A of the housing 21, and a holding frame side electromagnetic coil (vibration means) 127 is arranged to face the inner side surface 121B of the holding frame 121. Yes. Since the housing 21 and other configurations are the same as those of the heating device 10 described above, the same reference numerals are given and description thereof is omitted.
The second heating unit 115 has substantially the same configuration as the first heating unit 113 except that the top and bottom are reversed, and the casing 21 is disposed on the top surface 121C of the holding frame 121 via a spring (elastic member) 123. ing.
In this embodiment, the housing 21 is vibrated laterally with respect to the holding frame 121 by changing the magnetic field of each electromagnetic coil at a predetermined frequency. According to this configuration, in a state where the sheet body 1 is held between the infrared transmission plates 25, the infrared transmission plate 25 is vibrated in the lateral direction, so that the surface of the sheet body 1 is added to the heating by the infrared heater 23. Friction heat due to vibration can be applied to the.
For this reason, the temperature rising time of the sheet body 1 can be further shortened, and the heating efficiency can be improved. Furthermore, by heating the surface of the sheet body 1 with frictional heat, the stress of the carbon fibers existing in the vicinity of the surface can be reduced, and the internal stress generated in the sheet body when the temperature is raised can be reduced. 1 expansion can be further suppressed.

  As described above, according to the present embodiment, the heating device 10 for the sheet body 1 includes an infrared heater that heats the sheet body 1 to melt the sheet body 1 in the thickness direction of the sheet body 1 during heating. Since the infrared transmission plate 25 that regulates the expansion of the sheet body 1 and maintains the shape of the sheet body 1 is provided, the generation of an air layer in the sheet body 1 during heating is prevented. For this reason, shortening of the heating time until the sheet | seat body 1 fuse | melts can be implement | achieved, and the improvement of heating efficiency can be aimed at, without the resin material of the sheet | seat body 1 deteriorating.

  As mentioned above, although this invention was concretely demonstrated based on one Embodiment, this invention is not limited to the said embodiment, It can change in the range which does not deviate from the summary. In the present embodiment, the fiber-containing resin body has been described as a sheet body formed in a sheet shape, but other shapes such as a block body may be used as long as the shape of the preheating target is a constant shape.

1 Sheet body (fiber-containing resin body)
DESCRIPTION OF SYMBOLS 10, 120 Heating device 13, 113 1st heating part 15, 115 2nd heating part 17 Lifting device 21 Case 21A Outer side surface 23 Infrared heater (heating means)
25 Infrared transmitting plate (shape holding means)
125 Case side electromagnetic coil (vibration means)
127 Holding frame side electromagnetic coil (vibration means)

Claims (7)

In the heating method of the fiber-containing resin body for heating the fiber-containing resin body,
A method for heating a fiber-containing resin body, wherein the fiber-containing resin body is heated while restricting expansion during heating and maintaining the shape of the fiber-containing resin body.   The fiber-containing resin body is heated by a non-contact type heating means that irradiates the predetermined wavelength in a state where the fiber-containing resin body is held by a shape holding means that transmits a predetermined wavelength. Item 2. A method for heating a fiber-containing resin body according to Item 1.   The method for heating a fiber-containing resin body according to claim 2, wherein the predetermined wavelength is an infrared wavelength.   4. The fiber-containing resin body according to claim 2, wherein the surface of the fiber-containing resin body is heated by vibrating the shape holding means in contact with the surface of the fiber-containing resin body. Heating method. In the heating device for the fiber-containing resin body provided with heating means for heating the fiber-containing resin body,
An apparatus for heating a fiber-containing resin body, comprising shape holding means for restricting expansion during heating and holding the shape of the fiber-containing resin body.   The heating unit is a non-contact type heating unit that irradiates a predetermined wavelength, the shape holding unit has a function of transmitting the predetermined wavelength, and the shape holding unit holds the fiber-containing resin body. The apparatus for heating a fiber-containing resin body according to claim 5, wherein the fiber-containing resin body is heated by the heating means.   Vibrating means for vibrating the shape holding means in a state where the shape holding means and the surface of the fiber-containing resin body are in contact with each other, and heating the surface of the fiber-containing resin body with frictional heat generated by the vibration The apparatus for heating a fiber-containing resin body according to claim 5 or 6, characterized by the above.

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