JP7276065B2 - Structure and method of forming structure - Google Patents

Description

The present invention relates to a structure provided with a mortar frame formed using a three-dimensional printer and a method of forming the structure.

A three-dimensional (3D) printer may be used to form a three-dimensional structure. This 3D printer forms each layer by ejecting material from horizontally moving nozzles, and forms a three-dimensional shape by stacking each layer (see, for example, Patent Document 1 and Non-Patent Document 1). The structure forming system of Patent Literature 1 includes a nozzle attached to a robot arm, side members, and a controller. Then, the structure forming system moves the nozzle while discharging mortar downward from the discharge port of the nozzle to form the structure. In addition, Non-Patent Document 1 describes a bench configured by injecting ultra-high-strength fiber-reinforced concrete into an area surrounded by a frame formed by a 3D printer.

JP 2018-69661 A

Obayashi Corporation, "Developed a composite structure of special mortar for 3D printers and ultra-high strength fiber reinforced concrete", [online], [searched on September 10, 2019], Internet <URL: https://www .obayashi.co.jp/news/detail/news20190829_1.html>

When injecting the second mortar into the frame formed by the 3D printer using the first mortar, pressure (lateral pressure) is applied from the side of the frame by the injected second mortar. In this case, the frame may be damaged if the lateral pressure is large relative to the strength of the frame. Therefore, in order to resist the lateral pressure, it was necessary to make the frame thicker or to change the shape to be advantageous against the lateral pressure by adding ribs or the like. However, when thickening the frame, the frame material is increased. Furthermore, when the frame is thickened or ribs are added, the area into which the high-strength second mortar is injected is restricted. In this case, it may be structurally disadvantageous or restrict the design.

A structure for solving the above problems includes a first frame portion configured by laminating a first mortar having a first composition, a second frame portion provided facing the first frame portion, and the an internal structure configured by injecting a second mortar having a second composition into a space surrounded by a frame including a first frame and the second frame; and a first layer of the first frame. and a second layer having a height corresponding to the first layer of the second frame, and holding portions embedded in the second layer so as to bridge the first frame and the second frame. a separator embedded in the structure.

A method for forming a structure for solving the above problems includes a first frame portion configured by stacking a first mortar having a first composition while discharging a first mortar from a nozzle while moving the nozzle; A method of forming a structure by injecting a second mortar having a second composition different from the first composition into a space surrounded by a frame including a second frame provided opposite to the second frame. Laminating the first mortar to the height of the first layer of the first frame, and placing a separator holding portion extending from the second frame on the upper surface of the first layer, By laminating the first mortar on the holding portion, the holding portion of the separator is embedded in the first mortar.

According to the present invention, it is possible to withstand the lateral pressure of the second mortar injected into the frame with a simple structure.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of a structure according to an embodiment, where (a) is a top view and (b) is a cross-sectional view along line 1b-1b in (a); BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing of the separator in embodiment, Comprising: (a) is a short separator, (b) is a long separator, (c) is a separator which has a turnbuckle structure. Explanatory drawing explaining the structure of the three-dimensional printer in embodiment. The perspective view explaining the formation method of the structure in embodiment. FIG. 4 is an explanatory diagram of a separator shortened after the frame is cured in the embodiment; FIG. 11 is an explanatory diagram of a separator in a first modified example, where (a) is a front cross-sectional view and (b) is a plan view of a main part of a holding portion of the separator arranged in (a). It is a front view of the bolt used for the separator in the 2nd modification and the 3rd modification, (a) is a battledore-shaped bolt, (b) is a hook bolt. FIG. 11 is a front cross-sectional view of a state in which a separator is embedded in a fourth modification; FIG. 11 is a front cross-sectional view for explaining the arrangement of separators in a fifth modification;

An embodiment embodying a structure and a method for forming the structure will be described below with reference to FIGS. 1 to 5. FIG.
In this embodiment, the structure 10 shown in FIG. 1 is formed. 1(a) is a top view of the structure 10, and FIG. 1(b) is a cross-sectional view taken along line 1b--1b in FIG. 1(a).

As shown in FIG. 1(a), the structure 10 is composed of curved surfaces and has a plurality of cavities E1. The structure 10 includes an outer frame 11 that forms the outer shape and an inner frame 12 that forms the shape of the hollow portion E1.
The outer frame 11 and the inner frame 12 function as a first frame and a second frame, and are constructed by laminating a first mortar having a first composition. The first mortar is a curable cementitious material that can be laminated using a three-dimensional (3D) printer.

An internal structure 15 is formed in a region surrounded by the outer frame 11 and the inner frame 12 . The internal structure 15 is constructed by injecting a second mortar having a higher strength than the first composition of the first mortar into the outer frame 11 and the inner frame 12 . In this embodiment, as the second mortar, for example, a cement-based material (fiber-reinforced concrete material) mixed with fibers such as Slimcrete (registered trademark) is used.

A plurality of separators are embedded in the structure 10 at approximately the same height. Each separator is arranged at a position that suppresses the lateral pressure of the second mortar injected into the area surrounded by the outer frame 11 and the inner frame 12 . These separators are arranged so as to span the opposing portions of the frame (11, 12). Moreover, the separator has a height of about 10 mm.

In this embodiment, a plurality of types of separators 21, 22, 23 with different shapes and lengths are used. Although the details of the shape will be described later, the separator 23 is arranged at a portion where the lateral pressure is higher than that of the separators 21 and 22 . For example, the separator 23 is arranged in the portion that bulges outward (the side opposite to the side where the second mortar is injected) of the outer frame 11 and the inner frame 12 . The separator 22 is longer than the separator 21 and is arranged in a portion of the frame (11, 12) that spans the longer length.

FIG. 1(b) is a vertical cross-sectional view of a portion in which the separator 21 spanning the outer frame 11 and the inner frame 12 is embedded. Here, the separator 21 is arranged to extend horizontally between the outer frame 11 and the inner frame 12 facing each other at a predetermined height. Specifically, the ring portions 25 and 27 at the ends of the separator 21 are embedded in the outer frame 11 and the inner frame 12 , and the central portion of the separator 21 is embedded in the internal structure 15 .

<Configuration of Separators 21, 22, 23>
As shown in FIG. 2(a), the separator 21 includes an eyenut 21a and an eyebolt 21b. The eye nut 21a is formed by integrating a shaft portion 26 with a ring portion 25 having a through hole 25h. Axle 26 has a length of about 40 mm. A female thread (right-hand thread) is formed at the end of the shaft portion 26 on the opposite side to the ring portion 25 on the central axis thereof. The eyebolt 21b is formed by integrating a screw shaft 28 with a ring portion 27 having a through hole 27h. The threaded shaft 28 is approximately 30 mm and fits into the internal thread of the eyenut 21a. By screwing the eyenut 21a and the eyebolt 21b together, the length of the separator 21 can be changed, for example, by about 10 mm. Also, the ring portions 25 and 27 are embedded in the first mortar and function as holding portions that hold the arrangement of the separator.

The separator 22 shown in FIG. 2B is longer than the maximum length of the separator 21, has substantially the same configuration as the separator 21, and includes an eyenut 22a and an eyebolt 22b. The eye nut 22 a has a ring portion 25 integrally formed with a shaft portion 26 having a female screw (right-hand screw) formed at the end thereof. The eyebolt 22b has a threaded shaft 28 integrated with a ring portion 27, and the length of the separator 22 can be adjusted by, for example, about 20 mm depending on how the eyenut 22a is screwed into the shaft portion 26 of the eyebolt 22b.

The separator 23 shown in FIG. 2(c) is a separator having a turnbuckle function. This separator 23 has two eyenuts 23a and 23b and a stud bolt 23c. The eye nut 23a, like the eye nut 21a, is formed by integrating a shaft portion 26 of approximately 40 mm with a ring portion 25 having a through hole 25h. The eye nut 23a is formed with an internal thread (left-hand thread) in a direction different from that of the eye nut 21a.

The eye nut 23b is formed by integrating a shaft portion 29 having a length of about 10 mm with a ring portion 25 having a through hole 25h. A female thread (right-hand thread) is formed at the end of the shaft portion 29 of the eye nut 23 b opposite to the ring portion 25 . The stud bolt 23c is formed with a right-handed external thread and a left-handed external thread on both sides, respectively, and is screwed into each of the internal threads of the eyenuts 23a and 23b. The length of the separator 23 can be adjusted by rotating the stud bolt 23c without changing the orientation of the ring portion 25. As shown in FIG.

<Configuration of 3D printer>
Next, the configuration of the 3D printer 30 that forms the outer frame 11 and the inner frame 12 will be described with reference to FIG. Here, the outer frame layer 11a and the inner frame layer 12a are portions corresponding to one layer of the outer frame 11 and the inner frame 12 formed by the 3D printer 30, respectively.

The 3D printer 30 of this embodiment includes a nozzle 31 as a discharge section, a robot arm 35 and a control device 40 .
The tip of the nozzle 31 has a reduced diameter. An open ejection port 31 a is formed at the tip of the nozzle 31 . The end of the hose 32 is connected to the end of the nozzle 31 opposite to the discharge port 31a. Hose 32 is connected to a pressure pump (not shown). The first mortar supplied to the nozzle 31 through the hose 32 is discharged downward from the discharge port 31a by the pressure of the pressure pump.

A robot arm 35 as a moving means is attached to the nozzle 31 via an attachment portion 34 . The nozzle 31 is supported by the robot arm 35 and moves horizontally and vertically according to the movement of the robot arm 35 . Movement of the robot arm 35 is controlled by instructions from the control unit 41 of the control device 40 . The controller 41 of the present embodiment controls the robot arm 35 so that the direction of discharge of the first mortar from the nozzle 31 is always downward even during movement.

The control device 40 includes a control section 41, an input section (not shown) and an output section (not shown). The input unit has a keyboard, a pointing device, etc., and supplies information about the structure 10 to be formed to the control unit 41 . The output unit has a display or the like, and displays the input information, the paths of the nozzles 31 for forming the frames (11, 12), and the like.

The control unit 41 includes control means (CPU, RAM, ROM, etc.) and performs structure formation processing. Therefore, by executing the structure forming program stored in the storage unit, the control unit 41 functions as a stacking control unit 411 , a movement control unit 412 and a discharge amount control unit 413 .

The lamination management unit 411 executes processing for managing the path and height of mortar to be laminated in order to form a structure. The stacking management unit 411 stores layer heights, arrangement heights, and structure heights. The layer height is the height of one layer when formed by the first mortar discharged while moving the nozzle 31 . The placement height is the height of the mortar when the separators 21, 22, 23 are placed. The structure height is the height of the structure 10 and the height for completing the structure 10 . In this embodiment, the placement height and structure height are stored in layers. Furthermore, the lamination management unit 411 counts the number of laminated layers.

The movement control unit 412 executes processing for controlling the movement of the robot arm 35 that moves the nozzle 31 according to the path.
The discharge amount control unit 413 executes processing for controlling the pump that pumps the first mortar discharged from the nozzle 31 . The discharge amount control section 413 can adjust the discharge amount of the first mortar to discharge the first mortar to a spaced position.

<Method of Forming Structure 10>
Next, a method for forming the structure 10 described above will be described with reference to FIGS. 4 and 5. FIG.
First, the control unit 41 of the control device 40 forms the bottom layer (first layer) of the outer frame 11 and the inner frame 12 . Specifically, the movement control unit 412 of the control unit 41 arranges the nozzles 31 so as to correspond to the position of one inner frame 12, and discharges the first mortar from the discharge port 31a. According to the shape of the inner frame 12 , the robot arm 35 is moved to form one inner frame layer 12 a forming the inner frame 12 . When the inner frame layer 12a of the first layer is formed, the bottom layer of the other inner frame 12 on which the first layer has not yet been formed is formed in the same manner.

Then, when the first layer of the inner frame 12 is formed, the first layer of the outer frame 11 is formed in the same manner. Specifically, after arranging the nozzle 31 corresponding to the position of the outer frame 11 , the control unit 41 causes the first mortar to be discharged from the discharge port 31 a and moves the robot arm 35 according to the shape of the outer frame 11 . , to form the outer frame layer 11a of the first layer.

Then, when the formation of the first layer of the outer frame 11 and the inner frame 12 is completed, the ejection port 31a of the nozzle 31 is raised by one layer, and the upper layer of the outer frame 11 and the inner frame 12 ( second layer). Specifically, a second layer (upper layer) is formed on the first layer. This layer formation is repeated up to a predetermined number of layers (arrangement height).
When the layer is stacked up to the predetermined layer, the discharge amount control section 413 of the control section 41 stops discharging the first mortar from the nozzle 31 .

Next, the separators 21, 22, 23 are arranged at predetermined positions so as to bridge over the opposing frames (11, 12). In this case, the ring portions 25 and 27 of the separators 21, 22 and 23 are placed on the top surfaces of the uppermost outer frame layer 11a and inner frame layer 12a stacked up to the arrangement height. Here, the end portions of the ring portions 25 and 27 are arranged so as not to protrude from the outer frame layer 11a and the inner frame layer 12a. Furthermore, in this case, the ring portions 25 and 27 may be pressed against the outer frame layer 11a and the inner frame layer 12a, and part of the lower mortar may be inserted into the through holes 25h and 27h.

FIG. 4 shows locations where the separators 23 are arranged. In this case, the ring portion 25 of the separator 23 is arranged on the upper surface of the outer frame layer 11a of the first layer at the arrangement height and the inner frame layer 12a of the second layer at the arrangement height. And it is bridged so that the outer frame 11 and the inner frame 12 of the separator 23 may be connected.

After arranging the separators, the first mortar is laminated again on the inner frame layer 12a and the outer frame layer 11a on which the ring portions 25, 27 of the separators 21, 22, 23 are arranged. In this case, since the separators 21, 22, and 23 are lower than one layer, the newly laminated first mortar is less likely to have a step. Then, the control unit 41 stacks the inner frame layer 12a and the outer frame layer 11a up to the height of the structure by repeating the lamination of the first mortar, thereby forming the outer frame 11 and the inner frame 12 .

Next, the mortar forming the outer frame 11 and the inner frame 12 is cured.
Then, when the outer frame 11 and the inner frame 12 are almost cured, the length of the separator 23 is shortened by several millimeters. Specifically, as shown in FIG. 5, the stud bolts 23c of the separators 23 embedded in the outer frame 11 and the inner frame 12 are rotated in the tightening direction R1. Thereby, the length of the separator 23 can be shortened while the ring portion 25 is embedded in the outer frame 11 and the inner frame 12 . Therefore, the ring portions 25 of the separator 23 are brought close to each other, and the outer frame 11 and the inner frame 12 embedded in the ring portions 25 are pulled toward the center of the separator 23 .

After that, a second mortar is injected into the area surrounded by the outer frame 11 and the inner frame 12 . In this case, the injected second mortar presses the side surfaces of the outer frame 11 and the inner frame 12, but the embedded separators 21, 22, and 23 resist this side pressure (side pressure).
The second mortar is then dried to complete the structure 10. FIG.

(action)
According to this embodiment, the separators 21, 22, and 23 span the opposing frames (11, 12). Thereby, the interval between the frames (11, 12) included in the structure 10 and forming the outer shape of the structure 10 can be maintained even when the second mortar is injected.

Further, according to this embodiment, the separators 21, 22, and 23 are arranged and the first mortar is laminated during the formation of the outer frame 11 and the inner frame 12. FIG. Thereby, separators 21, 22, and 23 can be provided when laminating the first mortar.

According to this embodiment, the following effects can be obtained.
(1) In this embodiment, the separators 21, 22, and 23 can firmly connect the frames (11, 12), so that the lateral pressure of the second mortar forming the internal structure 15 can be resisted. Therefore, it is not necessary to change the shape of the frame (11, 12) to resist the lateral pressure, such as by increasing the thickness of the frame (11, 12).

(2) In the present embodiment, the ring portions 25 and 27 of the separators 21, 22 and 23 are placed on the outer frame layer 11a and the inner frame layer 12a laminated up to the arrangement height. Laminate the first mortar on top. As a result, the ring portions 25 and 27 can be embedded in the outer frame 11 and the inner frame 12 only by arranging the separators 21, 22 and 23 in the middle of lamination, so the separators 21, 22 and 23 can be efficiently embedded. can do.

(3) In this embodiment, the separators 21, 22, and 23 can be changed in length. Thereby, the separators 21, 22, 23 can be adjusted according to the distance between the frames (11, 12) to be bridged.

(4) Ring portions 25 and 27 having through holes 25h and 27h are formed at both ends of the separators 21, 22 and 23 of the present embodiment. Accordingly, when the first mortar is laminated on the separators 21, 22, and 23 arranged on the outer frame layer 11a and the inner frame layer 12a, the first mortar enters the through holes 25h and 27h. The ends of the separators 21, 22, 23 can be firmly embedded in the frames (11, 12).

(5) The separator 23 of this embodiment is shortened after the frames (11, 12) are cured. As a result, the tensile strength between the frames (11, 12) can be increased in advance before injecting the second mortar in the portion where the lateral pressure of the second mortar is further increased.

This embodiment can be implemented with the following modifications. This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
- The separators 21, 22, 23 of the above-described embodiments are configured using eyenuts 21a, 22a, 23a, 23b, eyebolts 21b, 22b and stud bolts 23c. The configuration of the separator is not limited to this.

For example, as shown in FIG. 6A, a separator 50 having T-shaped metal plates 51 at both ends may be used. The separator 50 is constructed by fixing two metal plates 51 as holding portions and a joining flat plate 52 for joining them together with bolts 53 and nuts 54 . Further, as shown in FIG. 6B, the metal plate 51 is formed with a plurality of through holes 51a, 51b, 51c, 51d. When the first mortar forming the frames (11, 12) is laminated, the metal plates 51 are embedded in the opposing frames (11, 12). The length of the separator 50 can be adjusted by loosening the bolts 53 and nuts 54 and sliding the connecting flat plate 52 . Moreover, since the portion embedded in the first mortar is thin, it is possible to make it difficult for the first mortar that is laminated after the separator 50 is placed to have a step.

Furthermore, the end portions of the eyebolts 21b and 22b in the above embodiment may be changed to a shape other than the ring portion 27 having the through hole 27h.
For example, as shown in FIG. 7A, the bolt B1 may include a battledore 55 having a plurality of through holes 55h. Furthermore, as shown in FIG. 7(b), instead of the ring-shaped eyebolts 21b and 22b having the through holes 27h, hook bolts B2 having a C-shaped member 57 having a notch 57a may be used.

Further, as shown in FIG. 8, engaging members 71 as holding portions that are bent downward are provided at both ends, and the engaging members 71 may be integrally configured via connecting members 72 to form a separator 70 . When the separator 70 is arranged on the upper surfaces of the outer frame layer 11a and the inner frame layer 12a formed up to the height of the arrangement, the tips of the engaging members 71 are pierced into the outer frame layer 11a and the inner frame layer 12a. Thereby, the separator 70 can be firmly arranged.

- In the above-described embodiment, the structure 10 is constructed by arranging the central portions of the separators 21, 22, and 23 in the region surrounded by the outer frame 11 and the inner frame 12, and injecting the second mortar. Parts of the frame formed of one member, such as a frame using a spiral shape or a frame formed by a single stroke, are bridged by a separator, and the second mortar is injected into the region surrounded by these frames. may

Further, in the above embodiment, all the frames are formed by a 3D printer, but some of the frames may be formed by a 3D printer. For example, as shown in FIG. 9, a wall frame 82 formed by a 3D printer is provided on a wall 81 . Specifically, after attaching the eyenut 21a of the separator 21 to the wall 81, the first mortar constituting the wall frame 82 is laminated to the arrangement height by a 3D printer. After that, the eyebolt 21b of the separator 21 is screwed into the eyenut 21a and the ring portion 27 of the separator 21 is placed on the wall frame 82 . Then, the first mortar is layered on the ring portion 27 to form the wall frame 82 . Furthermore, a second mortar is injected between the wall 81 and the wall frame 82 .

- In the above embodiment, all the separators 21, 22, and 23 are arranged at the arrangement height. The height at which a plurality of separators are arranged is not limited to the same height, and the height at which the separators are arranged can be changed according to the lateral pressure applied to the outer frame 11 and the inner frame 12, the shape of the structure 10, and the arrangement of the separators. good too.

B1... bolt, B2... hook bolt, E1... cavity, L1, L2... length, R1... tightening direction, 10... structure, 11... outer frame, 11a... outer frame layer, 12... inner frame, 12a... inner Frame layer 15 Internal structure 21, 22, 23, 50, 70 Separator 21a, 22a, 23a, 23b Eyenut 21b, 22b Eyebolt 23c Stud bolt 25, 27 Ring portion 25h , 27h, 51a, 51b, 51c, 51d, 55h... Through hole, 26, 29... Shaft part, 28... Screw shaft, 30... 3D printer, 31... Nozzle, 31a... Discharge port, 32... Hose, 34... Mounting part , 35... Robot arm, 40... Control device, 41... Control unit, 51... Metal plate, 52... Flat plate for joining, 53... Bolt, 54... Nut, 55... Battledore, 57... C-shaped member, 57a... Notch, 61... shaft, 63... flat plate, 71... engaging member, 72... connecting member, 81... wall, 82... wall frame, 411... lamination management unit, 412... movement control unit, 413... discharge amount control unit.

Claims (8)

a first frame portion configured by laminating a first mortar having a first composition;
a second frame provided facing the first frame;
an internal structure configured by injecting a second mortar having a second composition into a space surrounded by a frame including the first frame portion and the second frame portion;
holding portions embedded in a first layer of the first frame and a second layer of the second frame having a height corresponding to the first layer; and a separator embedded in the internal structure so as to span two frame portions. 2. The structure according to claim 1, wherein the second frame is constructed by laminating the first mortar. 3. The structure according to claim 1, wherein the holding portion is formed with a through hole through which the first mortar is inserted. The structure according to any one of claims 1 to 3, wherein the separator has a variable length. A first frame configured by moving the nozzle to stack a first mortar having a first composition while ejecting the first mortar from the nozzle; and a second frame provided opposite to the first frame. A method for forming a structure formed by injecting a second mortar having a second composition different from the first composition into a space surrounded by a frame, comprising:
Laminating the first mortar to the height of the first layer of the first frame,
placing a separator holding portion extending from the second frame portion on the upper surface of the first layer;
A method of forming a structure, wherein the holding portion of the separator is embedded in the first mortar by laminating the first mortar on the holding portion. The second frame is configured by laminating the first mortar,
When the first frame is laminated to the height of the first layer, the second frame is laminated to the second layer corresponding to the height of the first layer,
The holding portions of the separator are placed on the upper surfaces of the first layer and the second layer, respectively, and the first mortar is laminated on the holding portions to form the first frame portion and the second layer. 6. The method of forming a structure according to claim 5, wherein a frame is formed. A through hole through which the first mortar is inserted is formed in the holding portion,
7. The structure according to claim 5 or 6, wherein the first mortar layered on the holding part is joined to the first mortar under the holding part through the through hole. Forming method. the separator is of variable length;
8. The method of forming a structure according to claim 5, wherein the separator is shortened after curing the first mortar.

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