Heating device

Abstract

To reduce oxidative wear of a sheet-shaped heater in a heat device in which other materials are laminated on both sides of the heater.SOLUTION: A heating device includes a heating element 11 that generates heat when power is supplied, a first insulator 13 and a second insulator 14 that are laminated on the front and back surfaces of the heating element and cover the heating element, respectively, a first heat conductor 17 that is laminated on the first insulator and covers the first insulator, and a second heat conductor 18 that is laminated on the second insulator and covers the second insulator, and a peripheral structure 30 that seals the peripheries of the first insulator and the second insulator. The peripheral structure has its peripheries sealed by direct or indirect bonding of the first heat conductor and the second heat conductor.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a heating device suitable for heat fusing thermoplastic composite materials. [Background technology]

[0002] For example, thermal conduction fusion is a fusion technology for thermoplastic composites used in aircraft structural materials. In thermal conduction fusion, a heater is placed in contact with the outer surface of each thermoplastic composite, and the heat generated by the heater is transferred to the inside of the material, melting and pressurizing the fusion interface until it exceeds the melting point. Carbon Fiber Reinforced Thermo Plastics (CFRTP) is a typical example of a thermoplastic composite material used in aircraft structural materials. In order to fuse thermoplastic composites without causing internal defects, it is necessary to heat the fusion interface locally and quickly to a temperature above the melting point. For this reason, it is preferable to use graphite as the heater material and to apply a thin heater to minimize the heat capacity of the heater itself. However, graphite is subject to oxidation wear at high temperatures above 500°C, where it combines with oxygen in the atmosphere to generate CO2 and CO-derived gas, so graphite heaters have low durability.

[0003] Patent Document 1 proposes a fusion device that can realize efficient fusion in terms of time and energy (electricity). The fusion device in Patent Document 1 has a five-layer structure in which a sheet-like or thin-film graphite heater is sandwiched between insulating materials on both sides, and the insulating materials on the front and back are covered with an outer cover and an inner cover, respectively. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7275246 Summary of the Invention [Problem to be solved by the invention]

[0005] The fusion device of Patent Document 1 has a five-layer structure, and the graphite heater is provided with insulating materials and an outer cover or an inner cover on the front and back sides thereof, and the insulating materials and covers are expected to have the effect of preventing oxidation wear caused by bonding between the graphite heater and oxygen in the atmosphere. However, it is desired to further reduce oxidation wear. In view of the above, an object of the present disclosure is to further reduce oxidative wear of a heater in a heating device in which a sheet-shaped heater is laminated with other members from both sides as in Patent Document 1, for example. [Means for solving the problem]

[0006] The heating device according to the present disclosure comprises: A heating element that generates heat when power is supplied to it; a first insulator and a second insulator, which are laminated on the front surface and the back surface of the heating element, respectively, and cover the heating element; a first heat transfer body laminated on the first insulator and covering the first insulator, and a second heat transfer body laminated on the second insulator and covering the second insulator; and a peripheral structure that seals the peripheral edges of the first insulator and the second insulator. The peripheral structure according to the present disclosure is The first heat transfer body and the second heat transfer body are directly or indirectly joined to form a peripheral seal. Effect of the Invention

[0007] The heating device of the present disclosure has a peripheral structure in which the peripheral edge is sealed by directly or indirectly joining the first heat transfer body and the second heat transfer body, and this peripheral structure blocks the path of oxygen penetration into the heating body, thereby suppressing oxidative wear of the heating body. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a heating device according to an embodiment. [Diagram 2] 2 is a cross-sectional view of the heating device of FIG. 1 and an enlarged view of a portion thereof; [Diagram 3] FIG. 2 is a plan view of the heating device of FIG. [Figure 4] 2 is a diagram showing an example of thermal fusion of CFRTP by the heating device of FIG. 1. [Diagram 5] 13A and 13B are diagrams illustrating modified examples of the heating device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a heating device 1 according to an embodiment will be described with reference to the accompanying drawings. The heating device 1 is preferably used to join two members made of carbon fiber reinforced plastic (hereinafter, CFRTP) by fusion bonding, for example. The heating device 1 has a laminated structure with a sheet-shaped heating element sandwiched between them, and seals any points in the laminated structure that could be paths for oxygen to enter. The heating device 1 employs diffusion bonding as a preferred sealing method, thereby reducing the oxidative wear of the heating element 11.

[0010] [Configuration of heating device 1: Figures 1, 2, and 3] The heating device 1 is composed of a heating element 11, a first insulator 13 and a second insulator 14 each made of a pair of electrically insulating materials laminated on the front and back sides of the heating element 11, and a first heat transfer element 17 and a second heat transfer element 18 laminated on the first insulator 13 and the second insulator 14, respectively.

[0011] [About heating element 11] The heating element 11 is a sheet-like heating element that generates heat when power is supplied. As an example, this heating element is made of graphite, and generates heat when power is supplied. A graphite heater has a large amount of infrared radiation and can generate heat in a short time of less than one second, making it suitable for thermal fusion of CFRTP. However, the graphite heater is merely one preferred example in this disclosure. In addition, a carbon heater using carbon fiber as a heating element, a ceramic heater using alumina (Al2O3), silicon nitride (Si3N4), or the like as a heating element, a metal thin film heater, and the like can be used in this disclosure. The heating element 11 has a rectangular outer shape when viewed from above, but may have other shapes. Note that a rectangle refers to a quadrangle with four equal corners. In order to absorb thermal expansion when heated and to increase the amount of heating element laid per unit area, it is preferable to form the heating element 11 in a meandering pattern.

[0012] [First insulator 13, second insulator 14: see Figure 2] The first insulator 13 and the second insulator 14 are laminated on the front and back sides of the heating element 11, respectively. The first insulator 13 and the second insulator 14 are provided to electrically insulate the heating element 11 from the first heat conductor 17 and the second heat conductor 18. There is no limitation on the material constituting the first insulator 13 and the second insulator 14 as long as the material can electrically insulate the heating element 11 from the first heat conductor 17 and the second heat conductor 18. However, taking heat resistance into consideration, it is preferable to use mica as the first insulator 13 and the second insulator 14.

[0013] [First heat transfer body 17, second heat transfer body 18: see Figure 2] The first heat transfer body 17 and the second heat transfer body 18 are laminated on the first insulator 13 and the second insulator 14, respectively, and constitute the outer layers of the heating device 1. The first heat transfer body 17 and the second heat transfer body 18 transfer heat generated by the heating body 11 when power is supplied to the outside.

[0014] The first heat transfer body 17 is a member having a C-shaped cross section, and includes a flat heat transfer wall 17A and side walls 17B, 17B rising from both ends of the heat transfer wall 17A in the second direction W to be connected to the heat transfer wall 17A. A first surface 17A1 of the heat transfer wall 17A covers the surface of the first insulator 13, and a first surface 17B2 of the side wall 17B covers the sides of the insulator 13 and the heating body 11. In addition, a second surface 17A2 of the heat transfer wall 17A contacts the CFRTP member to be fused as the heating device 1 and transfers heat.

[0015] The first heat transfer body 17 is made of a material having excellent thermal conductivity and a predetermined rigidity. An example of a physical property value for evaluating thermal conductivity is thermal conductivity, and a material having a thermal conductivity of 10 W / m·K or more at room temperature is preferably used. An example of a physical property value for evaluating rigidity is Young's modulus, and a material having a Young's modulus of 30 GPa or more at room temperature is preferably used. Specific examples of suitable metal materials include copper or copper alloy, aluminum or aluminum alloy, and stainless steel. In addition to metal materials, high thermal conductive fine ceramics such as aluminum nitride and silicon carbide can also be used as the first heat transfer body 17. The second heat transfer body 18 is also made of the same type of material as the first heat transfer body 17. However, the first heat transfer body 17 and the second heat transfer body 18 may be made of different materials.

[0016] The second heat transfer body 18 is an entirely flat member, and is disposed opposite the heat transfer wall 17A of the first heat transfer body 17, with the heating body 11, the first insulator 13 and the second insulator 14 sandwiched therebetween.

[0017] In the heating device 1, the thickness of the portion where the heating element 11, the first insulator 13, the second insulator 14, the first heat transfer element 17, and the second heat transfer element 18 are stacked is preferably 10 mm or less, preferably 5 mm or less, and more preferably 3 mm or less. Furthermore, with regard to each element constituting the heating device 1, it is preferable that the thickness of the heating element 11 is 0.3 mm or less, the thickness of the first insulator 13 and the second insulator 14 is 0.3 mm or less, and the thickness of the first heat transfer element 17 and the second heat transfer element 18 is 1 mm or less.

[0018] [Peripheral structure: see Figures 2 and 3] The heating device 1 is provided with a peripheral structure 30 for suppressing oxidative wear of the heating element 11. This will be described in detail below. As a premise of this structure, the first insulator 13 and the second insulator 14 are formed to have a larger dimension in the second direction W than the heating element 11, and the first insulator 13 and the second insulator 14 protrude further outward in the second direction W than the heating element 11. A third insulator 15 is provided between the first insulator 13 and the second insulator 14 to fill the gap between the first insulator 13 and the second insulator 14. A joint 19 is provided between the side wall 17B and the first insulator 13, the second insulator 14, and the third insulator 15 in the second direction W. In FIG. 2, the joint 19 has a first surface 19A facing downward, a second surface 19B facing upward opposite the first surface 19A, a third surface 19C facing the side wall 17B, and a fourth surface 19D facing the third surface 19C. In the direction from the heating element 11 to the periphery in the second direction W, the heating element 11, the first insulator 13, the second insulator 14, the third insulator 15, the bonding body 19, and the side wall 17B are arranged in this order.

[0019] The joint body 19 is a rectangular parallelepiped member whose dimension in the first direction (L) is larger than that in the second direction W, and is made of the same material as the first heat transfer body 17 and the second heat transfer body 18, for example, a copper alloy. In the third direction T, the joint body 19 is disposed between the heat transfer wall 17A of the first heat transfer body 17 and the second heat transfer body 18, with the heat transfer wall 17A in contact with the first surface 19A and the second surface 19B in contact with the second heat transfer body 18. In the second direction W, the third surface 19C is in contact with the side wall 17B, and the fourth surface 19D is in contact with the first insulator 13, the second insulator 14, and the third insulator 15.

[0020] In order to reduce the oxidative wear of the heating element 11, the bonding body 19 is bonded to the heat transfer wall 17A of the first heat transfer body 17 on the first surface 19A, and is bonded to the second heat transfer body 18 on the second surface 19B. This blocks the path of oxygen penetration toward the heating element 11. In the present disclosure, diffusion bonding DB is adopted as a preferred bonding means. Diffusion bonding is a technique in which the base material is held in a heated and pressurized state without melting, and atoms at the bonding interface are diffused through the bonding surface to obtain a metallurgically integrated bonded portion. In the case of this embodiment, the bonding body 19 and the heat transfer wall 17A are metallurgically integrated with each of the first surface 19A and the second surface 19B as the bonding interface, and the bonding body 19 and the second heat transfer body 18 are integrated, so that oxygen can be prevented from entering from the corresponding portion toward the heating body 11. The bonding of the heat transfer wall 17A and the second heat transfer body 18 through the bonding body 19 in this manner corresponds to indirect bonding in the present disclosure. In addition, when a graphite heater is used as the heating body 11, it is recommended to perform diffusion bonding in a vacuum environment to avoid gasification of graphite.

[0021] In this embodiment, as long as the diffusion bonding state can be obtained by applying heat and pressure, the specific means are arbitrary. For example, the diffusion bonding can be performed using devices such as a hot press and HIP (Hot Isostatic Pressing). In addition, in the case of copper alloys, it is known that the diffusion bonding state can be obtained at the interface by resistance welding accompanied by pressure, and the diffusion bonding can also be performed by resistance welding. In the example shown in FIG. 2, resistance welding can be performed by heating while applying a load (F) at least between the heat transfer wall 17A and the second heat transfer body 18. According to JIS Z 3001, the diffusion bonding is defined as "a method of bonding by bringing members into close contact with each other, applying pressure to the extent that plastic deformation is minimized under a temperature condition below the melting point of the base material, and realizing a metal bond between the bonding surfaces." In addition, a heating temperature of about 400°C is used for the diffusion bonding of copper and copper alloys.

[0022] In this embodiment, diffusion bonding is used for at least the following two reasons. First, the objects to be joined (joint body 19, heat transfer wall 17A, and second heat transfer body 18) are metallically integrated, so that the intrusion of oxygen, which is the cause of oxidative wear, can be prevented. The second reason is that the first surface 19A and the second surface 19B, which are hidden inside by the heat transfer wall 17A and the second heat transfer body 18, must be joined, making it difficult to employ other joining techniques such as welding.

[0023] Although the peripheral structure 30 at both ends in the second direction W has been described above, the peripheral structure 30 is preferably provided also at both ends in the first direction L in plan view as shown in Fig. 3. In other words, the peripheral structure 30 is preferably provided over the entire area of ​​the periphery FR surrounding the first direction L and the second direction W.

[0024] [Example of fusion: see Figure 4] We will explain an example in which two members made of CFRTP are joined by fusion using a heating device 1. In this example, two heating devices 1, 1 are prepared, and their first heat transfer bodies 17, 17 are arranged above and below each other with a gap between them, facing each other. A pair of fusion targets 100A, 100B made of CFRTP are sandwiched between the first heat transfer bodies 17 and 17.

[0025] In the gap between the second heat transfer body 18 and the side walls 17B, 17B, for example, a heat insulator 101 can be placed without any gaps. Providing the heat insulator 101 prevents the heat generated by the heating body 11 from being discharged to the outside instead of being directed toward the fusion targets 100A, 100B. The heat insulator 101 also serves as a load for the fusion targets 100A, 100B.

[0026] In addition, the heat insulator 101 is disposed so as to be in contact with the second heat transfer body 18, thereby blocking the multiple cooling grooves 18A formed in the second heat transfer body 18 from the third direction T. Therefore, the portion of the cooling groove 18A other than the first direction L becomes a closed space. After the heating required for fusing the fusion objects 100A, 100B is performed, it is preferable that the fusion parts are quickly solidified. Therefore, after the necessary heating is performed, cooling air is continuously supplied to the cooling groove 18A forming this closed space. The supplied air cools the fusion objects 100A, 100B via the second heat transfer body 18, and therefore solidification of the fusion parts can be promoted.

[0027] Although an example in which two heating devices 1, 1 are used has been described above, it is also possible to use only one heating device 1 to fuse the fusion objects 100A, 100B.

[0028] [Effect of heating device 1] As described above, according to the heating device 1, the portions that can be a path for oxygen to penetrate into the heating element 11 are blocked by the diffusion bond DB, so that oxidation wear of the heating element 11 can be suppressed during fusion of the CFRTP. In particular, the diffusion bond DB metallurgically bonds the joining body 19 and the first heat transfer body 17, and the joining body 19 and the second heat transfer body 18 together, and has a high degree of blocking the path for oxygen to penetrate.

[0029] Moreover, according to the heating device 1, the bonded body 19 can be diffusion-bonded while applying a load L in the third direction T in which the bonded body 19 is sandwiched between the first heat transfer body 17 and the second heat transfer body 18. Therefore, according to the heating device 1, by heating while applying the load L to the same direction and the same region, it is possible to easily obtain two diffusion bonds, that is, the bonded body 19 and the heat transfer wall 17A and the bonded body 19 and the second heat transfer body 18.

[0030] Furthermore, according to the heating device 1, since the bonding body 19 is interposed between the first heat transfer body 17 and the second heat transfer body 18, the first heat transfer body 17 and the second heat transfer body 18 can use flat plate materials with simple shapes for the opposing surfaces including the diffusion bonding portion. Therefore, the heating device 1 has low production costs.

[0031] [Modifications of peripheral structure: see Figure 5] Although one example of a preferred peripheral structure has been described, in this embodiment, the peripheral structure described below can be adopted.

[0032] In the heating device 1, the diffusion bonding is performed using the bonding body 19, but in the present disclosure, the peripheries of the first heat transfer body 17 and the second heat transfer body 18 can be directly diffusion bonded without using the bonding body 19. This corresponds to the direct bonding in the present disclosure. In other words, in the heating device 1, a part corresponding to the bonding body 19 prepared as a separate body is provided in the first heat transfer body 17 or the second heat transfer body 18. FIG. 5 shows an example (Ex. 1) in which a bonding portion 17C corresponding to the bonding body 19 is formed in the first heat transfer body 17, and an example (Ex. 2) in which a bonding portion 18D corresponding to the bonding body 19 is formed in the second heat transfer body 18. The bonding portion 17C is formed so that the dimension (wall thickness) in the third direction T is larger than other regions of the heat transfer wall 17A at the periphery of the heat transfer wall 17A, and is formed along the side wall 17B. The joint 18D is formed at the periphery of the second heat transfer body 18 so as to have a larger dimension in the third direction T than other regions of the second heat transfer body 18. By using the first heat transfer body 17 having the joint 17C and the second heat transfer body 18 having the joint 18D, the effort of preparing the joint 19 in addition to the first heat transfer body 17 and the second heat transfer body 18 can be saved.

[0033] In the example described below, the direction of diffusion bonding is different from the peripheral structures described so far. That is, the diffusion bonding in the peripheral structures described so far is provided parallel to the first heat transfer body 17 and the second heat transfer body 18, but as in the example shown in FIG. 5 (Ex. 3), the diffusion bonding DB can be provided so as to intersect, typically perpendicular to, the first heat transfer body 17 and the second heat transfer body 18. In this example, the side wall 17B of the first heat transfer body 17 is prepared as a separate member from the heat transfer wall 17A. That is, a side wall 21, which is a substitute for the side wall 17B, is provided on the side surface of the first heat transfer body 17 and the side surface of the second heat transfer body 18, and the side wall 21 and the side surface of the first heat transfer body 17 and the side wall 21 and the side surface of the second heat transfer body 18 are diffusion bonded. During diffusion bonding, a load (F) is applied in the direction shown in the figure.

[0034] In addition, in the above embodiment, diffusion bonding is exemplified as a preferred bonding method, but the present disclosure can employ other bonding methods exemplified below. (1) Material joining (a) Arc welding, gas welding, resistance welding, laser welding (b) Brazing and soldering (c)Friction Stir Welding (FSW) (2)Chemical bonding Adhesion (using heat-resistant inorganic adhesive) (3) Mechanical bonding (a) Conclusion (b) Shrink fitting, cold fitting Other elements may be added to the configurations described in the above embodiments. For example, another layer, such as a highly heat-conductive sheet, may be interposed between the second heat transfer body 18 and the second insulator 14 in order to suppress in-plane temperature unevenness of the heat generating body 11.

[0035] The present disclosure can be understood as follows. [Appendix 1] A heating element (11) that generates heat when power is supplied; a first insulator (13) and a second insulator (14) that are laminated on the front and back surfaces of the heating element (11) and cover the heating element (11); a first heat transfer body (17) laminated on the first insulator (13) and covering the first insulator (13), and a second heat transfer body (18) laminated on the second insulator (14) and covering the second insulator (14); a peripheral structure (30) that seals the peripheral edges (FR) of the first insulator (13) and the second insulator (14); The peripheral structure (30) is A heating device (1) whose periphery is sealed by direct or indirect bonding of a first heat transfer body (17) and a second heat transfer body (18). [Appendix 2] In the above-mentioned embodiment, preferably, the peripheral edges of the first heat transfer body (17) and the second heat transfer body (18) protrude outward beyond the peripheral edges of the first insulator (13) and the second insulator (14); The peripheral structure (30) is a joint body (19) that is located outside the first insulator (13) and the second insulator (14) and is fitted into the first heat transfer body (17) and the second heat transfer body (18); The first heat transfer body (17) and the bonding body (19) are diffusion bonded to each other, and the second heat transfer body (18) and the bonding body (19) are diffusion bonded to each other. [Appendix 3] In addition 1 or addition 2, preferably The first heat transfer body (17) and the second heat transfer body (18) are The optical fiber has a first direction (L) and a second direction (W) perpendicular to the first direction (L), and has a rectangular shape in a plan view. The peripheral structure (30) is The heat transfer member is provided over the entire periphery of the first heat transfer body (17) and the second heat transfer body (18). [Appendix 4] In any one of Supplementary Note 1 to Supplementary Note 3, preferably, The first heat transfer body (17) is the heat transfer wall (17A) has a rectangular shape in a plan view and has a first direction (L) and a second direction (W) perpendicular to the first direction (L); and a pair of side walls (17B, 17B) rising from both sides of the heat transfer wall (17A) in the first direction (L); The heat transfer wall (17A) and the pair of walls (17B, 17B) are integrally formed. [Appendix 5] In any one of Supplementary Notes 1 to 4, preferably, The second heat transfer body (18) is The shape of the electrode in a plan view is rectangular, and the electrode has a first direction (L) and a second direction (W) perpendicular to the first direction (L); a first surface (18B) in contact with the second insulator (14) and a second surface (18C) on the rear side of the first surface (18B); A plurality of cooling grooves (18A) for flowing a cooling medium are formed in the second surface (18C) along the first direction (L). [Appendix 6] In any one of Supplementary Notes 1 to 5, preferably, The heating element (11) is a sheet-shaped heater made of graphite, The first heat transfer body (17) and the second heat transfer body (18) are made of a copper alloy. In addition to the above, it is possible to select and discard the configurations given in the above embodiment, or to change them to other configurations as appropriate. [Explanation of symbols]

[0036] 1 Heating device 11 Heating element 13 First insulator 14 Second insulator 15 Third Insulator 17 First heat transfer body 17A heat transfer wall 17A1 1st page 17A2 2nd side 17B Side wall 17C joint 18 Second heat transfer body 18A cooling groove 18B 1st page 18C 2nd side 18D joint 19 Zygote 19A 1st page 19B 2nd side 19C 3rd page 19D 4th page 21 Side wall 30 Peripheral Structure 100A, 100B fusion target 101 Insulation DB Diffusion Bonding F load L 1st direction W 2nd direction T 3rd direction

Claims

1. A heating element that generates heat when power is supplied to it; a first insulator and a second insulator, which are laminated on the front surface and the back surface of the heating element, respectively, and cover the heating element; a first heat transfer body that is laminated on the first insulator and covers the first insulator, and a second heat transfer body that is laminated on the second insulator and covers the second insulator; a peripheral structure that seals the peripheral edges of the first insulator and the second insulator, The peripheral structure is A heating device, wherein the periphery is sealed by direct or indirect bonding of the first heat transfer body and the second heat transfer body.

2. the first heat transfer body and the second heat transfer body have peripheral edges that protrude outward beyond the peripheral edges of the first insulator and the second insulator, The peripheral structure is a joining body that is located outside the first insulator and the second insulator and is fitted to the first heat transfer body and the second heat transfer body, The first heat transfer body and the bonding body are diffusion bonded, and the second heat transfer body and the bonding body are diffusion bonded. The heating device according to claim 1 .

3. The first heat transfer body and the second heat transfer body are The optical fiber has a first direction and a second direction perpendicular to the first direction, and has a rectangular shape in a plan view. The peripheral structure is The first heat transfer body and the second heat transfer body are provided over the entire peripheral area thereof. The heating device according to claim 2 .

4. The first heat transfer body is A heat transfer wall having a rectangular shape in a plan view, the heat transfer wall having a first direction and a second direction perpendicular to the first direction, and a pair of side walls rising from both sides of the heat transfer wall in the second direction, The heat transfer wall and the pair of side walls are integrally formed. The heating device according to claim 1 .

5. The second heat transfer body is The shape of the projection 100 in a plan view is rectangular, the projection 100 having a first direction and a second direction perpendicular to the first direction; a first surface in contact with the second insulator and a second surface on the rear side of the first surface; A plurality of cooling grooves for flowing a cooling medium are formed in the second surface along the first direction. The heating device according to claim 1 .

6. The heating element is a sheet-shaped heater made of graphite, The first heat transfer body and the second heat transfer body are made of copper or a copper alloy. A heating device according to any one of claims 1 to 5.

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