Adhesive method for composite materials

Abstract

To suitably bond a composite material without bagging, without being restricted by a shape.SOLUTION: A method for bonding a composite material for bonding a composite material to a bonding object executes the steps of: arranging the composite material in a bonding region of the bonding object through an adhesive; heating a plurality of local regions as a part of the bonding region while pressing, and temporarily bonding the composite material to the bonding object; and heating the temporarily bonded whole bonding region, and finally bonding the composite material to the bonding object.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a method for bonding composite materials.

Background Art

[0002] Conventionally, a method for bonding composite materials is known in which the bonding portion between the object to be bonded and the composite material is heated while applying pressure over the entire area for bonding (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, when bonding a composite material to an object to be bonded, in order to prevent the generation of air bubbles in the bonding portion between the object to be bonded and the composite material, it is hermetically sealed with a bagging film, and heating is performed by an autoclave in a state where the inside of the bagging film is evacuated. However, when the object to be bonded or the composite material has a complex shape, there may be difficulties in manufacturability such as damage to the bagging film in bonding using the bagging film. For this reason, it is conceivable to perform baggingless bonding as in Patent Document 1, but when the object to be bonded or the composite material is a large part used in an aircraft or the like, it becomes less practical due to shape constraints.

[0005] Therefore, an object of the present disclosure is to provide a method for bonding composite materials that can preferably bond composite materials without being restricted by shape and without bagging.

Means for Solving the Problems

[0006] The method for bonding a composite material according to the present disclosure is a method for bonding a composite material to an object to be bonded. In the method, a step of disposing the composite material on the bonding region of the object to be bonded via an adhesive, a step of heating while pressing a plurality of local regions that are part of the bonding region to temporarily bond the composite material to the object to be bonded, and a step of heating the entire bonded region that has been temporarily bonded to permanently bond the composite material to the object to be bonded are performed.

Advantages of the Invention

[0007] According to the present disclosure, the composite material can be suitably bonded without being restricted by the shape and without bagging.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. Note that the present invention is not limited by this embodiment. Also, the components in the following embodiments include those that can be replaced by those skilled in the art and are easy to replace, or those that are substantially the same. Furthermore, the components described below can be combined as appropriate, and when there are a plurality of embodiments, the embodiments can also be combined.

[0010] [Embodiment] FIG. 1 is an explanatory diagram showing a method for bonding a composite material according to the present embodiment. FIG. 2 is an explanatory diagram showing local regions in the bonding region.

[0011] The method for bonding composite materials according to this embodiment is a method of bonding a composite material 6 to an object to be bonded 5 to form a bonded structure 1. The object to be bonded 5 may be a composite material or may be a metal or the like, and is not particularly limited. In this embodiment, the case where the method is applied to a composite material as the object to be bonded 5, that is, the case of bonding composite materials to each other will be described. Further, the method for bonding the composite material 6 according to this embodiment is a bonding method suitable for parts used in an aircraft, which are large and have a complex shape, as the object to be bonded 5 and the composite material 6.

[0012] The composite material 6 is, for example, a fiber-reinforced plastic obtained by impregnating a reinforcing fiber with a resin and curing it. As the reinforcing fiber, for example, carbon fiber or the like is used, and as the resin, for example, a thermosetting resin or the like is used. The reinforcing fiber and the resin are not particularly limited.

[0013] (Method for bonding composite materials) First, in the method for bonding the composite material 6, a step S1 of arranging the composite material 6 in the bonding region E1 of the object to be bonded 5 is executed. In this embodiment, the object to be bonded 5 is a plate-shaped composite material, and the bonding region E1 is the entire upper surface. Specifically, in step S1, an adhesive sheet 8 formed in a sheet shape is arranged over the entire bonding region E1 of the object to be bonded 5. After that, in step S1, the composite material 6 is arranged on the adhesive sheet 8. In step S1, when the adhesive sheet 8 is interposed between the object to be bonded 5 and the composite material 6, the adhesive sheet 8 is heated and melted to fill the gap between the object to be bonded 5 and the composite material 6 with the adhesive without any gaps.

[0014] Subsequently, in the method for bonding the composite material 6, a step S2 of temporarily bonding the composite material 6 to the object to be bonded 5 by heating a plurality of local regions E2 that are part of the bonding region E1 while applying pressure is executed. In step S2, as the apparatus used for temporary bonding, a temporary bonding apparatus 10 including a plurality of clamps 11, a plurality of heaters 12, a plurality of temperature sensors 13, and a control unit 15 is applied.

[0015] The plurality of clamps 11 serve as a jig that sandwiches the object to be bonded 5 and the composite material 6 from both sides and presses the local region E2. Here, as shown in FIG. 2, the plurality of local regions E2 pressed by the plurality of clamps 11 are evenly arranged with respect to the bonding region E1. Specifically, the local region E2 is a circular region. Also, the plurality of local regions E2 are arranged in a grid pattern.

[0016] The plurality of heaters 12 are provided corresponding to the plurality of clamps 11 and are respectively provided between the clamp 11 and the bonding structure 1. The heater 12 heats the local region E2 to thermoset the adhesive, thereby temporarily bonding the object to be bonded 5 and the composite material 6. The plurality of heaters 12 are connected to the control unit 15 and are respectively temperature-controlled by the control unit 15.

[0017] The plurality of temperature sensors 13 are provided corresponding to the plurality of heaters 12 and are provided at positions where the temperature of the local region E2 can be measured. The plurality of temperature sensors 13 are connected to the control unit 15 and respectively output the temperature of the local region E2 measured toward the control unit 15.

[0018] The control unit 15 adjusts the heating temperature of the local region E2 by controlling the temperature of the heater 12 based on the measured temperature of the temperature sensor 13.

[0019] In step S2, a plurality of bonding portions are formed by temporarily bonding the plurality of local regions E2 using the above-described temporary bonding device 10. The plurality of bonding portions impart a restraining force to restrain the object to be bonded 5 and the composite material 6 against the internal pressure generated by the expansion of the adhesive in the main bonding described later.

[0020] Next, in the method for bonding the composite material 6, a step S3 of heating the entire bonded area E1 of the temporarily bonded composite material 6 and then permanently bonding the composite material 6 to the object 5 to be bonded is performed. In step S3, the temporarily bonded bonded structure 1 is placed in a heating furnace 20, and in the heating furnace 20, the bonded area E1 of the bonded structure 1 is uniformly heated. Here, the heating temperature for temporary bonding in step S2 and the heating temperature for permanent bonding in step S3 are the same. When the bonded structure 1 is heated in step S3, the adhesive thermally expands, generating an internal pressure between the object 5 to be bonded and the composite material 6. On the other hand, since the object 5 to be bonded and the composite material 6 are constrained in a plurality of local areas E2 (bonded portions), the internal pressure between the object 5 to be bonded and the composite material 6 is difficult to decrease, suppressing the generation of air bubbles in the adhesive. Then, by performing the permanent bonding in step S3, the object 5 to be bonded and the composite material 6 become integrated, and the bonding of the composite material 6 is completed.

[0021] As described above, the method for bonding the composite material 6 according to the embodiment is understood as follows, for example.

[0022] The method for bonding the composite material 6 according to the first aspect is a method for bonding the composite material 6 to the object 5 to be bonded. In the method for bonding the composite material 6, a step S1 of disposing the composite material 6 via an adhesive (adhesive sheet 8) in the bonded area E1 of the object 5 to be bonded, a step S2 of heating while pressing a plurality of local areas E2 that are part of the bonded area E1 to temporarily bond the composite material 6 to the object 5 to be bonded, and a step S3 of heating the entire bonded area E1 of the temporarily bonded composite material 6 to permanently bond the composite material 6 to the object 5 to be bonded are performed.

[0023] According to this configuration, even if the object 5 to be bonded and the composite material 6 are large and have a complex shape, temporary bonding can be suitably performed in the local area E2. Also, in the permanent bonding, the generation of air bubbles can be suppressed by the internal pressure generated between the object 5 to be bonded and the composite material 6. Therefore, the composite material 6 can be suitably bonded without being restricted by the shape of the object 5 to be bonded and the composite material 6, and without bagging.

[0024] As a second aspect, in step S3 of firmly bonding the composite material 6, the plurality of bonding portions bonded in the plurality of local regions E2 have a restraining force against the internal pressure generated by the expansion of the adhesive due to heating.

[0025] According to this configuration, it is possible to suppress the separation of the object to be bonded 5 and the composite material 6 due to the internal pressure caused by the expansion of the adhesive. In addition, since it is possible to suppress the decrease in the internal pressure, it is possible to suitably suppress the generation of bubbles.

[0026] As a third aspect, the plurality of local regions E2 are evenly arranged with respect to the bonding region E1.

[0027] According to this configuration, since the uneven distribution of the restraining force can be suppressed, the restraint between the object to be bonded 5 and the composite material 6 can be maintained throughout the entire bonding region E1.

[0028] As a fourth aspect, the heating temperature in step S2 of temporarily bonding the composite material 6 and the heating temperature in step S3 of firmly bonding the composite material 6 are the same temperature.

[0029] According to this configuration, the thermosetting of the adhesive can be suitably performed in both temporary bonding and permanent bonding.

[0030] As a fifth aspect, in step S3 of firmly bonding the composite material 6, the bonding region E1 is heated uniformly.

[0031] According to this configuration, since the timing of thermosetting in the bonding region E1 can be made substantially simultaneous, the bonding between the object to be bonded 5 and the composite material 6 can be suitably performed.

[0032] As a sixth aspect, in step S1 of arranging the composite material 6, the adhesive is an adhesive sheet 8 formed in a sheet shape, and the adhesive sheet 8 between the object to be bonded 5 and the composite material 6 is heated and melted.

[0033] According to this configuration, since the adhesive can be filled between the object to be bonded 5 and the composite material 6 without any gaps, the formation of air bubbles can be suppressed, and the bonding quality can be improved.

Explanation of symbols

[0034] 1 Bonding structure 5 Object to be bonded 6 Composite material 8 Adhesive sheet 10 Temporary bonding device 11 Clamp 12 Heater 13 Temperature sensor 15 Control unit

Claims

1. In a method for bonding a composite material to an object to be bonded, a step of disposing the composite material via an adhesive in an adhesive region of the object to be bonded; a step of heating a plurality of local regions that are part of the adhesive region while applying pressure to temporarily bond the composite material to the object to be bonded; a step of heating the entire adhesively bonded region that has been temporarily bonded to permanently bond the composite material to the object to be bonded. A method for bonding a composite material that performs these steps.

2. In the step of permanently bonding the composite material, the plurality of bonded portions bonded in the plurality of local regions have a restraining force against the internal pressure generated by the expansion of the adhesive due to heating. The method for bonding a composite material according to Claim 1.

3. The method for bonding a composite material according to Claim 1 or 2, wherein the plurality of local regions are evenly arranged with respect to the adhesive region.

4. The method for bonding a composite material according to any one of Claims 1 to 3, wherein the heating temperature in the step of temporarily bonding the composite material and the heating temperature in the step of permanently bonding the composite material are the same temperature.

5. In the step of permanently bonding the composite material, the method for bonding a composite material according to any one of Claims 1 to 4, wherein the adhesive region is heated uniformly.

6. In the step of disposing the composite material, the adhesive is an adhesive sheet formed in a sheet shape, and the adhesive sheet between the object to be bonded and the composite material is heated and melted. The method for bonding a composite material according to any one of Claims 1 to 5.

Images