JP-7854666-B2 - Method for interlayer reinforcement in the layering direction in a layered 3D printer

JP7854666B2JP 7854666 B2JP7854666 B2JP 7854666B2JP-7854666-B2

Inventors

深津志向
梶田秀幸
西脇智哉
宮田賢優
清水耕史

Assignees

前田建設工業株式会社
国立大学法人東北大学

Dates

Publication Date: 20260507
Application Date: 20240903

Claims (4)

A method for reinforcing the interlayers of a layered structure when constructing a building by layering construction materials extruded from the material extrusion nozzle of a layered 3D printer, A laminated structure formation process involves discharging construction materials from a material discharge nozzle to form a laminated structure consisting of multiple layers , After forming the aforementioned multi-layered laminated structure, a reinforcing material insertion step is performed in which a reinforcing material is inserted into the construction material such that, after forming the aforementioned multi-layered laminated structure, a reinforcing material is inserted into the layer boundary of the construction material in the multi-layered laminated structure so as to penetrate from the upper layer to the lower layer of the laminated structure, and the head of the reinforcing material does not protrude from the construction material located at the uppermost layer, and is located inside the construction material rather than on the surface of the construction material. A method for interlayer reinforcement in the stacking direction in a stacked 3D printer, characterized by including the following:
The method for interlayer reinforcement in the layering direction in a layered 3D printer according to claim 1 , characterized in that, in the reinforcing material insertion step, the insertion angle of each reinforcing material is kept constant when inserting the reinforcing material into the construction material.
The interlayer reinforcement method in the stacking direction of a stacking type 3D printer according to claim 1 or 2, characterized in that, in the reinforcing material insertion step, the positions of the reinforcing material to be inserted in the stacking structural unit located in the upper layer and the stacking structural unit located in the layer directly below the stacking structural unit located in the upper layer are different from each other in the horizontal direction.
The interlayer reinforcement method in the stacking direction of a stacking type 3D printer according to any one of claims 1 to 3, characterized in that the reinforcing material has a uniform and straight cross-section.

Description

This invention relates to a method for interlayer reinforcement in the layering direction of a layered 3D printer. In recent years, additive manufacturing (3D) printers, which use 3D printing technology to create structures layer by layer, have been developed in the construction sector both domestically and internationally. These printers primarily use cement-based materials, supplying mortar mixed in a mixer to the 3D printing device via pump. Construction using 3D printers allows for the layering of structures without formwork, offering significant advantages over conventional concrete construction in terms of labor savings, design flexibility, and safety. Concrete structures fabricated with a layered 3D printer are created by layering cement-based materials, resulting in discontinuous layers, such as cold joints, between layers. The presence of these discontinuous layers can lead to a reduction in strength due to the fragility between layers, compared to conventional concrete structures. Conventional techniques address this problem by reinforcing the mechanical strength between layers by inserting metallic fibers in the layering direction (see, for example, Patent Documents 1-3). The technology described in Patent Document 1 relates to an interlayer-reinforced 3D printed concrete structure and a method for constructing the same. This construction method includes the following steps: Printing a first layer of the printing material; Positioning horizontal bars section by section along a first direction of the first layer of the printed material for multiple sections of horizontal bars; Gradually printing a second layer of the printing material along the first direction as the horizontal bars are positioned, and injecting short bars into pre-set injection positions before printing them into the short bar injection positions. In this step, the horizontal bars are injected into the first layer of the printing material, and the upper parts of the short bars are exposed from the upper surface of the first layer of the printing material. According to this construction method, by positioning horizontal bars between layers of the 3D printed material and injecting short bars, the interlayer adhesion properties of the printing material can be effectively strengthened. The technology described in Patent Document 2 involves vertically inserting multiple steel fibers into a lamellar concrete material. The technology described in Patent Document 3 relates to a method for manufacturing components from a curable material. This component manufacturing method includes the following steps: printing at least one layer of the material using a 3D printing process; introducing multiple similar reinforcing elements into the layer; and periodically repeating the above two steps until the component is complete. Chinese Patent Application Publication No. 109680954Chinese Utility Model Application Publication No. 206233586International Publication No. 2019/092162 A schematic diagram of a layered 3D printer according to an embodiment of the present invention.A flowchart of a method for interlayer reinforcement in the stacking direction in a stacked 3D printer according to an embodiment of the present invention.Flowchart of the reinforcing material insertion process.Schematic diagram of a test specimen for mechanical testing.An explanatory diagram showing the results of a bending test (comparison with and without reinforcing material).An explanatory diagram showing the results of the bending test (comparison between cast-in and laminated construction). The following describes, with reference to the drawings, an interlayer reinforcement method in the stacking direction of a stacking 3D printer according to an embodiment of the present invention (hereinafter sometimes abbreviated as "interlayer reinforcement method"). Figures 1 to 6 illustrate the interlayer reinforcement method in the stacking direction of a stacking 3D printer according to an embodiment of the present invention. Figure 1 is a schematic diagram of the stacking 3D printer, Figures 2 and 3 are flowcharts of the interlayer reinforcement method, Figure 4 is a schematic diagram of a test specimen for mechanical testing, Figure 5 is an explanatory diagram showing the bending test results (comparison with and without reinforcement), and Figure 6 is an explanatory diagram showing the bending test results (comparison between impregnation and stacking). <Overview of Inter-story Reinforcement Methods> As shown in Figure 1, the interlayer reinforcement method according to an embodiment of the present invention relates to a method for reinforcing the interlayers of a laminated structure when constructing a building by laminating construction materials (e.g., cement-based materials) extruded from a material ejection nozzle of a laminated 3D printer. As shown in Figure 2, this interlayer reinforcement method includes a laminated structure formation step (S10) and a reinforcing materia