Manufacturing method for structural members

Abstract

The present invention provides a method for manufacturing structural members that allows for the easy creation of water-repellent portions on structural members when manufacturing them using additive manufacturing equipment. [Solution] The method comprises a lower mold manufacturing step for manufacturing the lower mold portion 5 of the structural member 1, and a structural member molding step for forming the structural member 1 by extruding material onto the upper surface of the lower mold portion 5 using an additive manufacturing device. In the lower mold manufacturing step, an inclined surface 512 is formed on the front portion of the upper surface of the lower mold portion 5, which gradually slopes downward from the rear to the front. The structural member molding step comprises a molding step for forming the structural member 1 on the front portion by extruding material onto the upper surface of the lower mold portion 5 using an additive manufacturing device, which has a water-repellent portion 23 on its lower surface that follows the shape of the inclined surface 512, and a demolding step for removing the structural member 1 from the lower mold portion 5.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a structural member.

Background Art

[0002] In recent years, an additive manufacturing technology has been proposed in which a cement-based material is additively manufactured to form a structural member (see, for example, Patent Document 1). It is difficult to construct an entire structure such as a building frame with a 3D printer (additive manufacturing apparatus) due to reasons such as the size of the additive manufacturing apparatus. Therefore, when constructing a structure using additive manufacturing technology, structural members manufactured by the additive manufacturing apparatus are joined together at the site.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the case of an assembly construction method in which structural members are stacked from bottom to top, a water return may be provided to the structural members in order to prevent water from entering the horizontal joints and ensure watertight performance. However, since the manufacturing of structural members by an additive manufacturing apparatus has lower accuracy than the manufacturing of structural members by a formwork construction method, it is difficult to form fine shapes such as water returns.

[0005] Therefore, an object of the present invention is to provide a method for manufacturing a structural member in which a water return portion can be easily formed on the structural member in the manufacturing of the structural member by an additive manufacturing apparatus.

Means for Solving the Problems

[0006] To achieve the above objective, the method for manufacturing a structural member according to the present invention comprises a lower mold manufacturing step for manufacturing a lower mold portion of a structural member, and a structural member molding step for forming the structural member by extruding material onto the upper surface of the lower mold portion using an additive manufacturing apparatus, wherein in the lower mold manufacturing step, an inclined surface is formed on the front portion of the upper surface of the lower mold portion that gradually slopes downward from the rear to the front, and the structural member molding step comprises a molding step for forming the structural member having a water-repellent portion on the front portion whose lower surface is shaped to conform to the inclined surface by extruding material onto the upper surface of the lower mold portion using the additive manufacturing apparatus, and a demolding step for removing the structural member from the lower mold portion.

[0007] In this invention, a water-repellent portion can be easily formed on the front portion of the lower part of a structural member by extruding material onto a lower mold portion on which a sloping surface is formed on the front portion of the upper surface that gradually slopes downward from the rear to the front.

[0008] In the method for manufacturing a structural member according to the present invention, the structural member has a lower part located on the lower side, an intermediate part located in the middle of the vertical direction, and an upper part located on the upper side, and the structural member molding process includes a lower part molding step in which a material is discharged onto the upper surface of the lower part mold using the additive manufacturing apparatus to form the lower part having a water-repellent portion on the front side whose lower surface is shaped to conform to the inclined surface, an intermediate part molding step in which a material is discharged onto the upper surface of the lower part using the additive manufacturing apparatus to form the intermediate part, an upper part molding step in which a material is discharged onto the rear side of the upper surface of the intermediate part using the additive manufacturing apparatus to form the upper part, and a demolding step in which the lower part, the intermediate part, and the upper part, which have hardened and become integrated, are removed from the lower part mold.

[0009] This configuration allows for the easy formation of a water-repellent portion on the front portion of the lower side of the structural member. By forming the upper portion of the structural member on top of the rear portion of the intermediate section, a void can be formed in front of the upper portion and above the front portion of the intermediate section. When the structural members are stacked vertically, the water-repellent portion of the upper structural member can be placed in this void.

[0010] In the method for manufacturing a structural member according to the present invention, in the upper part forming step, the material discharge port of the additive manufacturing apparatus may be shifted to a position behind the intermediate part forming step, and the material may be discharged to a position behind the intermediate part, and the material discharged behind the intermediate part may be cut off before the material hardens.

[0011] By using this configuration, the upper part can be manufactured while keeping the forward and backward movement distance of the material discharge port of the additive manufacturing device when creating the upper part the same as the forward and backward movement distance of the material discharge port of the additive manufacturing device when creating the lower part and the middle part.

[0012] In the method for manufacturing a structural member according to the present invention, in the lower mold manufacturing step, the upper surface of the lower mold may be covered with a sheet, and in the structural member molding step, the material may be extruded onto the sheet using the additive manufacturing apparatus.

[0013] This configuration allows the lower mold section to be easily removed from the structural member.

[0014] In the method for manufacturing a structural member according to the present invention, in the structural member forming step, either a convex portion or a concave portion with a shape that can be fitted together with one another may be formed on the lower part of the structural member, and the other may be formed on the upper part of the structural member.

[0015] This configuration allows for easy alignment of adjacent structural members vertically by fitting together the recesses or protrusions of the upper structural member with the protrusions or recesses of the lower structural member when stacking the structural members vertically. [Effects of the Invention]

[0016] According to the present invention, a water-repellent portion can be easily formed on a structural member during the manufacturing of that structural member using an additive manufacturing apparatus. Furthermore, watertightness can be improved in a masonry construction method using structural members manufactured by an additive manufacturing apparatus. [Brief explanation of the drawing]

[0017] [Figure 1]It is a cross-sectional view of a wall portion of a building provided with a structural member. [Figure 2] It is a view showing a lower mold part manufacturing process. [Figure 3] It is a view showing a process of forming an inclined surface in the lower mold part manufacturing process. [Figure 4] It is a view showing a process of installing a sheet in the lower mold part manufacturing process. [Figure 5] It is a view showing a lower part shaping process and an intermediate part shaping process. [Figure 6] It is a view showing an upper part shaping process. [Figure 7] It is a view showing an upper part shaping process following FIG. 6. [Figure 8] It is a view showing a lower mold part manufacturing process and a structural member shaping process according to a modification of the embodiment. [Figure 9] It is a cross-sectional view of a wall portion of a building provided with a structural member according to a modification of the embodiment. [Figure 10] It is a view showing a process of forming a convex portion and a protruding portion.

Mode for Carrying Out the Invention

[0018] Hereinafter, a method for manufacturing a structural member according to an embodiment of the present invention will be described based on FIGS. 1 to 7. The method for manufacturing a structural member according to the present embodiment is a method for manufacturing a structural member 1 assembled in the vertical direction as shown in FIG. 1. The structural member 1 is, for example, an exterior material provided on the wall portion 11 of a building. The structural member 1 is designed to provide a joint portion 12 between adjacent structural members 1 in the vertical direction when assembled. A waterproof mortar 121 and a sealing material 122 are provided in the joint portion 12. In the following description, the structural member 1 is in the posture provided on the wall portion 11 of the building. The surface side that becomes the outer wall surface of the structural member 1 in the horizontal direction is denoted as the front side, and the opposite side that becomes the inner side of the building is denoted as the rear side. The direction connecting the front side and the rear side is denoted as the front-rear direction. The horizontal direction orthogonal to the front-rear direction is denoted as the width direction. In the drawing, the front-rear direction is indicated by an arrow A. In the drawing, the width direction is a direction orthogonal to the paper surface.

[0019] Structural member 1 is manufactured by layering materials such as cement-based material using an additive manufacturing device (3D printer, not shown). Structural member 1 has a lower part 2 located at the bottom, an intermediate part 3 located in the middle in the vertical direction, and an upper part 4 located at the top. The lower part 2, intermediate part 3, and upper part 4 are integrated together. The front portion of the lower surface 21 of the lower part 2 has an inclined surface 211 that gradually slopes downward from the rear to the front. The portion 212 of the lower surface 21 of the lower part 2 that is behind the 211 is a horizontal surface. The upper surface 22 of the lower part 2 is a horizontal surface. In a plan view from the top and bottom, the portion of the lower part 2 where the inclined surface 211 is formed is referred to as the water-repellent portion 23, and the portion behind the water-repellent portion 23 is referred to as the rear portion 24.

[0020] The intermediate section 3 is provided on the entire upper surface 22 of the lower section 2. The lower surface 31 and upper surface 32 of the intermediate section 3 are horizontal planes. The intermediate section 3 and the lower section 2 have the same dimensions in the front-to-back and width directions. The upper section 4 is located on the rear portion of the upper surface 32 of the intermediate section 3. When viewed from above, the upper section 4 is positioned behind the rear edge 231 of the water-repellent section 23 of the lower section 2. The front portion of the upper surface 32 of the intermediate section 3 is exposed and not covered by the upper section 4. The lower surface 41 and upper surface 42 of the upper section 4 are horizontal planes. The upper section 4 is smaller in the front-to-back direction than the lower section 2 and the intermediate section 3. The width dimension of the upper section 4 is the same as the width dimension of the lower section 2 and the intermediate section 3.

[0021] When the structural members 1 are stacked vertically, the upper part 4 of the lower structural member 1 and the rear part of the rear portion 24 of the lower part 2 of the upper structural member 1 face each other vertically, and waterproof mortar 121 is filled between them. The front-to-back middle portion of the middle part 3 of the lower structural member 1 and the front part of the rear portion 24 of the lower part 2 of the upper structural member 1 face each other vertically, and sealant 122 is filled between them. The sealant 122 is in contact with the front surface 43 of the upper part 4 of the lower structural member and the front surface of the waterproof mortar 121. The front portion 33 of the middle part 3 of the lower structural member 1 and the water-repellent portion 23 of the upper structural member 1 are spaced apart vertically. The front end, i.e., the lower end, of the inclined surface 211 of the water-repellent portion 23 of the upper structural member 1 is positioned above the upper surface 32 of the middle part 3 of the lower structural member 1.

[0022] A method for manufacturing the structural member 1 will be described. As shown in Figures 2 to 4, the lower mold part 5, which forms the lower surface 21 (see Figure 1) of the lower part 2, is manufactured using an additive manufacturing apparatus (lower mold part manufacturing process). As shown in Figure 2, the additive manufacturing apparatus extrudes a material such as cement-based material to form a lump 51, which will be the predecessor of the lower mold part 5. As shown in Figure 3, an inclined surface 512 corresponding to the inclined surface 211 of the lower part 2 is formed on the front portion of the upper surface 511 of the lump 51. For example, the inclined surface 512 is formed by cutting off the front and upper corners 513 of the lump 51 by an operator. Alternatively, the lower mold part 5 having the inclined surface 512 may be formed by extruding material using an additive manufacturing apparatus. In this way, the lower mold part 5 having the inclined surface 512 on its upper surface 53 is manufactured. As shown in Figure 4, the upper surface 53 of the lower mold part 5 is covered with a sheet material 54 such as a vinyl sheet. The sheet material 54 is positioned so that its surface is shaped to resemble the shape of the upper surface 53 of the lower mold part 5.

[0023] The material is extruded onto the sheet material 54 of the lower mold section 5 using an additive manufacturing apparatus to form the structural member 1 (structural member forming process). The additive manufacturing apparatus extrudes material onto the sheet material 54 covering the upper surface 53 of the lower mold part 5 to form the lower part 2 having a water return section 23 on its front portion (lower part molding process). The material is extruded over the entire area above the upper surface 53 of the lower mold part 5 and allowed to harden. The intermediate section 3 is formed by extruding material onto the entire upper surface 22 of the lower section 2 using an additive manufacturing apparatus (intermediate section forming process). The upper part 4 is formed by extruding material onto the rear portion of the upper surface 32 of the intermediate part 3 using an additive manufacturing apparatus (upper part forming process). In the upper part forming process, the material discharge port of the additive manufacturing apparatus is shifted further back than when forming the lower part 2 and intermediate part 3, and moved in the front-to-back direction by the same length as the lower part 2 and intermediate part 3. As a result, as shown in Figure 6, the rear portion 44 of the material of the extruded upper part 4 protrudes behind the lower part 2 and intermediate part 3. The portion of the intermediate part 3 that protrudes behind the lower part 2 and intermediate part 3, i.e., the rear portion 44, is cut off before hardening, as shown in Figure 7. The rear end surfaces 25, 35, and 45 of the lower part 2, intermediate part 3, and upper part 4 are arranged to be approximately flush with each other.

[0024] The material is hardened, and the integrated lower part 2, middle part 3, and upper part 4 are removed from the lower mold part 5 (demolition process). Because the lower mold part 5 is covered with sheet material 54, the structural member 1 can be easily removed from the lower mold part.

[0025] In this way, the structural member 1 is manufactured. The manufactured structural member is assembled into the wall portion 11 of the building, and joints are provided between the upper and lower structural members 1,1.

[0026] Next, the operation and effects of the method for manufacturing structural members according to this embodiment will be described. In the manufacturing method of structural members according to this embodiment, a water-repellent portion 23 can be easily formed on the structural member 1 by extruding the material for the structural member 1 onto the lower mold portion 5 on which an inclined surface 512 manufactured by an additive manufacturing device is formed. By forming the upper portion 4 of the structural member 1 on the rear portion of the intermediate portion 3, a void 46 can be formed in front of the upper portion 4 and above the front portion of the intermediate portion 3. When the structural members 1 are stacked in the vertical direction, the water-repellent portion 23 of the upper structural member 1 can be placed in this void 46. In a masonry construction method using structural members 1 manufactured by an additive manufacturing device, the watertightness of the joint portion 12 can be improved.

[0027] In the upper section molding process, the material discharge port of the additive manufacturing device is shifted further back than in the intermediate section molding process, and the material is discharged to a position behind the intermediate section 3. Before the material hardens, the rear portion 44 that has been discharged behind the intermediate section 3 is cut off. In this way, the upper section 4 can be manufactured while keeping the front-to-back movement distance of the material discharge port of the additive manufacturing device during the molding of the upper section 4 the same as the front-to-back movement distance of the material discharge port of the additive manufacturing device during the molding of the lower section 2 and the intermediate section 3.

[0028] Although embodiments of the method for manufacturing structural members according to the present invention have been described above, the present invention is not limited to the above embodiments and can be modified as appropriate without departing from the spirit of the invention. For example, in the lower mold manufacturing process, the lower mold 5 may be manufactured without using additive manufacturing equipment. In the above embodiment, the structural member 1 has a lower part 2, an intermediate part 3, and an upper part 4, with a water-repellent portion 23 provided on the lower part 2, and a void 46 formed on the upper part for arranging the water-repellent portion 23 of the structural member positioned above. The structural member 1 does not need to have a void 46 if a water-repellent portion 23 is provided, nor does it need to be formed by dividing it into upper and lower parts such as the lower part 2, intermediate part 3, and upper part 4.

[0029] In the upper part molding process, the material for the upper part 4 is extruded to the position of the rear end of the lower part 2 and the intermediate part 3, and it is not necessary to extrude it so that it overflows to the rear. The lower mold portion 5 is covered with sheet material 54, but it does not need to be covered with sheet material 54 as long as the hardened lower portion 2 can be removed without any problems.

[0030] In the structural member fabrication process, either a convex portion or a concave portion with a shape that can be fitted together may be formed on the lower part (lower side portion 2) of the structural member 1, and the other may be formed on the upper part (middle portion 3 or upper side portion 4) of the structural member 1. With this configuration, when the structural members 1 are stacked vertically, the recesses or protrusions of the upper structural member 1 and the protrusions or recesses of the lower structural member 1 can be fitted together, making it easy to align adjacent structural members vertically.

[0031] In the manufacturing method of the structural member 1B with such a configuration, as shown in Figure 8, for example, in the lower mold manufacturing process, a protrusion 55 is provided on the upper surface 53 of the lower mold 5B. The protrusion 55 may be provided by extruding material onto the upper surface 53 of the lower mold 5B, or by installing a member that has been pre-formed into a predetermined shape onto the upper surface 53 of the lower mold 5B. In the lower part molding process of the structural member molding process, material is extruded onto the upper surface 53 of the lower mold 5B using an additive manufacturing device to form a recess 26 corresponding to the protrusion 55 on the lower surface 21 of the lower part 2B. If the upper surface 53 of the lower mold 5B is covered with sheet material 54, the protrusion 55 is also covered with sheet material 54.

[0032] The intermediate part molding process and the upper part molding process are performed to provide a protrusion 47 on the upper surface 42 of the upper part 4B. The protrusion 47 may be provided by extruding material onto the upper surface 42 of the upper part 4B, or by installing a member that has been pre-formed into a predetermined shape. As shown in Figure 9, structural members 1B manufactured in the same manner are stacked by fitting the recess 26 of the upper structural member 1B into the protrusion 47 of the lower structural member 1B. The depth dimension of the recess 26 is made smaller than the protrusion dimension of the protrusion 47. In this way, a gap is created between the upper surface 42 of the upper part 4B of the lower structural member 1B and the lower surface 21 of the lower part 2B of the upper structural member 1B. This gap becomes the space for waterproof mortar 121 to be provided.

[0033] As shown in Figure 10, when a protrusion 55 is provided on the upper surface 53 of the lower mold portion 5B, or a convex portion 47 is provided on the upper surface 42 of the upper portion 4B of the structural member 1, guide lines 13 may be provided on the upper surface 53 of the lower mold portion 5B and the upper surface 42 of the upper portion 4B to guide the position of the protrusion 55 and the convex portion 47. For example, a projection 144 or the like may be provided at the tip of the nozzle 14 of the additive manufacturing apparatus that extrudes the material to form the lower mold portion 5B and the upper portion 4B, and the guide lines may be automatically drawn by moving the nozzle 14 while bringing this projection 144 into contact with the upper surfaces 53 and 42 of the already laminated layers.

[0034] In the above embodiment, structural members 1,1 that have been manufactured in advance in a factory or similar facility are stacked on-site. Alternatively, the lower part 2 may be manufactured first, then installed in the installation location, and the intermediate part 3 and upper part 4 may be manufactured on top of the lower part 2 installed in the installation location using an additive manufacturing device.

[0035] The Sustainable Development Goals (SDGs) are among the 17 international goals adopted at the UN Summit in September 2015. The method for manufacturing structural members according to this embodiment can contribute to achieving goals such as "Goal 12: Responsible Consumption and Production" among the 17 Sustainable Development Goals (SDGs). [Explanation of Symbols]

[0036] 1. Structural members 2 Lower part 3. Middle section 4. Upper part 5 Lower mold part 12 Joint area 23 Water return section 54 Sheet material 211 Slope

Claims

1. The lower mold manufacturing process for producing the lower mold portion of the structural member, The process includes a structural member forming step in which material is extruded onto the upper surface of the lower mold portion using an additive manufacturing apparatus to form the structural member, In the lower mold manufacturing process, a sloping surface is formed on the front portion of the upper surface of the lower mold, gradually sloping downwards from the rear to the front. The aforementioned structural member fabrication process is as follows: A molding process in which the additive manufacturing apparatus extrudes material onto the upper surface of the lower mold to form the structural member having a water-repellent portion on its front side whose lower surface is shaped to conform to the inclined surface, A method for manufacturing a structural member, comprising a demolding step of removing the structural member from the lower mold portion.

2. The aforementioned structural member is The lower part located on the lower side, The intermediate part located in the middle of the vertical direction, It has an upper part located on the upper side, The aforementioned structural member fabrication process is as follows: The lower part molding process involves using the additive manufacturing apparatus to extrude material onto the upper surface of the lower mold portion to form the lower part having a water return portion on its front side that conforms to the inclined surface, The intermediate part forming step involves extruding material onto the upper surface of the lower part using the additive manufacturing apparatus to form the intermediate part, The additive manufacturing apparatus includes an upper part forming step in which material is extruded into the rear portion of the upper surface of the intermediate part to form the upper part, A method for manufacturing a structural member according to claim 1, comprising a demolding step of removing the lower portion, the intermediate portion, and the upper portion, which have hardened and become integrated from the lower mold portion.

3. The method for manufacturing a structural member according to claim 2, wherein in the upper part molding step, the material discharge port of the additive manufacturing apparatus is shifted to a position further back than the intermediate part molding step, the material is discharged to a position further back than the intermediate part, and the material discharged further back than the intermediate part is cut off before the material hardens.

4. In the lower mold manufacturing process, the upper surface of the lower mold is covered with a sheet. The method for manufacturing a structural member according to any one of claims 1 to 3, wherein in the structural member molding step, the material is extruded onto the sheet using the additive manufacturing apparatus.

5. In the aforementioned structural member fabrication process, A method for manufacturing a structural member according to any one of claims 1 to 3, wherein either a convex portion or a concave portion having a shape that can be fitted together is formed on the lower part of the structural member, and the other is formed on the upper part of the structural member.

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