Method for manufacturing precast concrete members and cap members used in the manufacturing method thereof.

Abstract

To shorten a manufacturing time and reduce a cost by easily manufacturing a precast concrete member in which a joint member is embedded.SOLUTION: A precast concrete member 1 is manufactured in which a joint member 10 is embedded by using a cap member 28 which includes a cap attachment male screw 22 formed with an outer diameter engaged with a screw-knotted reinforcement coupling female screw 16, a cap 24 provided at the end of the cap attachment male screw 22 in an axial direction, a male screw member coupling female screw 26 provided penetrating the cap 24 from the cap 24 to the cap attachment male screw 22 and formed with an inner diameter of a prescribed value irrespective of the size of the outer diameter of the cap attachment male screw 22, and a rotation operation locking member 28 for rotating the cap 24 formed on an outer end surface 2402 of the cap 24 positioned opposite to the cap attachment male screw 22.SELECTED DRAWING: Figure 12

Description

【Technical Field】 【0001】 The present invention relates to a method for manufacturing a precast concrete member and a cap member used in the manufacturing method. 【Background Art】 【0002】 When constructing a concrete structure, concrete caulking may be performed to drive new concrete into a precast concrete member. For concrete caulking, a joint member such as a screw tie bar screwed into one end in the axial direction of an elongated cylindrical portion having an internal thread formed on its inner peripheral portion is used. 【0003】 For example, in Patent Document 1, a reinforcing bar is connected to a joint member (relay joint) embedded in a precast concrete member, and concrete is placed and cured in a concrete accommodating portion surrounded by precast concrete members on four sides to form a footing in which the placed concrete portion and the precast concrete member are integrated. 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2018-59340 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 Conventionally, to manufacture precast concrete members with pre-embedded joint members as described above, through holes are made in the steel plates that make up the concrete formwork. The opening of the female thread of the joint member is placed against the inner surface of the steel plate, coaxially with the through holes. The male thread member is inserted through the through holes in the steel plate from the outer surface of the steel plate and screwed into the female thread of the joint member, thereby attaching the joint member to the steel plate. Then, concrete is poured into the concrete formwork and allowed to harden, after which the concrete formwork is removed and the precast concrete member is taken out. 【0006】 Incidentally, the outer diameter of the threaded reinforcing bars protruding from the precast concrete member is selected to match the cross-sectional area and length of the concrete member that will be newly poured and integrated with the precast concrete member via the threaded reinforcing bars. Conventionally, each time a precast concrete member is manufactured, a joint member having a female thread that can be screwed into the threaded reinforcing bar used is created. A male threaded member with an outer diameter that screws into the female thread of the joint member is also prepared. Then, through holes are formed in the steel plates that make up the concrete formwork so that these male threaded members can be inserted into them. In other words, the manufacturing of precast concrete components was complicated, time-consuming, and costly. 【0007】 The present invention has been made in view of the above circumstances, and aims to provide a method for manufacturing a precast concrete member, which allows for the easy manufacture of a precast concrete member in which a joint member is embedded, and is advantageous in shortening manufacturing time and reducing costs, as well as a cap member used in the manufacturing method. [Means for solving the problem] 【0008】 To achieve the above-mentioned objective, one embodiment of the present invention is a method for manufacturing a precast concrete member in which a joint member for providing a protruding threaded reinforcing bar is embedded, comprising: an elongated cylindrical portion having a female thread for connecting threaded reinforcing bars formed on its inner circumference into which the threaded reinforcing bar can be screwed; a joint member having a female thread opening for connecting threaded reinforcing bars formed at one end of the cylindrical portion in the axial direction; a male threaded portion for attaching a cap, formed with an outer diameter that screws into the female thread for connecting threaded reinforcing bars; and the threaded reinforcing bar provided at the axial end of the male threaded portion for attaching the cap. A cap member comprising: a lid portion that closes the female thread opening with the male thread portion for cap attachment screwed into the female thread for muscle connection; a female thread for connecting the male thread member that penetrates the lid portion and extends from the lid portion to the male thread portion for cap attachment, and is formed with an inner diameter of a predetermined value regardless of the size of the outer diameter of the male thread portion for cap attachment; a rotational locking portion for rotating the lid portion formed on the outer end surface of the lid portion opposite to the male thread portion for cap attachment; and a male thread provided so as to be screwable into the female thread for connecting the male thread member. A male threaded member having a screw is prepared, and the male threaded portion for cap attachment of the cap member is connected to the female thread for connecting the threaded reinforcing bars of the joint member, and the female threaded opening is closed with the lid to form a joint-cap assembly. A hole for inserting the male threaded member is provided in the plate material constituting the concrete formwork, allowing the male threaded member to be inserted, and the outer end surface of the lid is in contact with the outer surface of the lid, coaxially with the hole for inserting the male threaded member, and the male threaded member inserted into the hole is placed in front of the inner surface of the plate material constituting the inner surface of the concrete formwork. The joint-cap assembly is attached to the inner surface of the plate material by screwing it into the female thread for connecting the male thread member, concrete is poured into the concrete formwork to manufacture the precast concrete member inside the concrete formwork, and after manufacturing, the male thread member is removed from the female thread for connecting the male thread member to remove the precast concrete member from the concrete formwork, and the cap member is removed from the joint-cap assembly by engaging a tool with the locking part for rotation and rotating it. Furthermore, in one embodiment of the present invention, the locking portion for rotational operation is formed in a predetermined shape regardless of the size of the outer diameter of the male thread portion for cap attachment. Furthermore, in one embodiment of the present invention, the male threaded portion for cap attachment of the cap member is connected to the female threaded portion for connecting threaded reinforcing bars of the joint member, and when viewed from the axial direction of the female threaded portion for connecting threaded reinforcing bars, the lid portion is formed with a larger contour than the cylindrical portion. Furthermore, one embodiment of the present invention is characterized by comprising: a male threaded portion for attaching a cap, formed with an outer diameter that screws into a female thread for connecting threaded reinforcing bars; a lid portion provided at the axial end of the male threaded portion for attaching a cap, having an outer diameter larger than the outer diameter of the male threaded portion for attaching a cap; a female thread that penetrates the lid portion and extends from the lid portion to the male threaded portion for attaching a cap, having an inner diameter of a predetermined value regardless of the size of the outer diameter of the male threaded portion for attaching a cap; and a locking portion for rotational operation formed on the outer end surface of the lid portion, which is located opposite the male threaded portion for attaching a cap, for rotating the lid portion. Furthermore, in one embodiment of the present invention, the locking portion for rotational operation is formed in a predetermined shape regardless of the size of the outer diameter of the male thread portion for cap attachment. [Effects of the Invention] 【0009】 According to one embodiment of the present invention, a cap member is provided that screws onto the female thread for connecting threaded reinforcing bars of a joint member, and the cap member is provided with a female thread for connecting a male threaded member, which has an inner diameter of a predetermined value regardless of the size of the female thread for connecting threaded reinforcing bars of the joint member. Therefore, the joint member can be used as a male threaded member for fixing to the formwork plate, regardless of the size of the outer diameter of the threaded reinforcing bars protruding from the precast concrete member via the joint member, and a predetermined outer diameter can be used. In addition, the inner diameter of the male threaded member insertion hole provided in the formwork plate can be formed to a predetermined inner diameter, regardless of the size of the outer diameter of the threaded reinforcing bars protruding from the precast concrete member via the joint member. Therefore, it is no longer necessary to prepare male threaded members with different outer diameters each time to accommodate the varying outer diameters of threaded reinforcing bars that protrude from precast concrete members via joint members, and it is also no longer necessary to redrill male threaded member insertion holes with different inner diameters in the formwork plates each time. This allows for the easy manufacture of precast concrete members with embedded joint members, resulting in a manufacturing method for precast concrete members that is advantageous in reducing manufacturing time and costs. 【0010】 Furthermore, if the locking portion for rotational operation is formed in a predetermined shape regardless of the size of the outer diameter of the male threaded portion for cap attachment, it becomes unnecessary to prepare a tool each time to accommodate the different sizes of outer diameters of the threaded reinforcing bars protruding from the precast concrete member via the joint member. Therefore, the cap member can be attached to and removed from the joint member with a single tool, which is advantageous in improving work efficiency in the manufacturing of precast concrete members. 【0011】 Furthermore, if the lid portion is formed with a larger outline than the cylindrical portion when viewed from the axial direction of the female thread for connecting threaded reinforcing bars, it is advantageous in manufacturing aesthetically pleasing precast concrete members, as it prevents the production of precast concrete members in which the concrete portion filled on the outside of the lid portion easily breaks, or incomplete precast concrete members with gaps on the outside of the lid portion. Furthermore, this is advantageous for stably attaching the joint-cap connector to the inner surface of the concrete formwork. 【0012】 Furthermore, a cap member is provided that screws onto the female thread for connecting threaded reinforcing bars, and the cap member is provided with a female thread formed with a predetermined inner diameter, regardless of the size of the inner diameter of the female thread for connecting threaded reinforcing bars. Therefore, for example, when attaching a joint member having a female thread for connecting threaded reinforcing bars to a concrete formwork plate, a male threaded member with a predetermined outer diameter can be used regardless of the size of the inner diameter of the female thread for connecting threaded reinforcing bars. Furthermore, the inner diameter of the hole for inserting the male threaded member provided in the concrete formwork plate can be formed with a predetermined inner diameter regardless of the size of the inner diameter of the female thread for connecting threaded reinforcing bars. Therefore, it becomes unnecessary to prepare male threaded members with different outer diameters each time to accommodate the varying outer diameters of threaded reinforcing bars that protrude from precast concrete members via joint members. Furthermore, it becomes unnecessary to redrill insertion holes for male threaded members with different inner diameters in the formwork plates each time. This allows for the easy manufacture of precast concrete members with embedded joint components, which is advantageous in reducing manufacturing time and costs. 【0013】 Furthermore, if the locking portion for rotational operation is formed in a predetermined shape regardless of the size of the outer diameter of the male threaded portion for cap attachment, it becomes unnecessary to prepare a tool each time to accommodate the different sizes of outer diameters of the threaded reinforcing bars protruding from the precast concrete member via the joint member. Therefore, the cap member can be attached to and removed from the joint member with a single tool, which is advantageous in improving work efficiency in the manufacturing of precast concrete members. [Brief explanation of the drawing] 【0014】 [Figure 1] This is a perspective view of a precast concrete member with an embedded joint component. [Figure 2] (A) is a perspective view showing an example of a joint member according to this embodiment, and (B) is a cross-sectional view of the joint member. [Figure 3] (A) is a front view of the cap member according to this embodiment, and (B) is a rear view of the cap member. [Figure 4] (A) is a side view of the cap member according to this embodiment, and (B) is a side cross-sectional view of the cap member. [Figure 5] It is a perspective view showing an example of a concrete formwork. [Figure 6] (A) is a cross-sectional view showing the state before attaching the cap member to the joint member, and (B) is a cross-sectional view of the joint-cap combined body with the cap member attached to the joint member. [Figure 7] It is a manufacturing procedure of a precast concrete member. (A) is a cross-sectional view showing a male screw member insertion hole provided in a concrete formwork, and (B) is a cross-sectional view showing the joint-cap combined body arranged on the inner surface of the concrete formwork. [Figure 8] It is a continuation of the manufacturing procedure of the precast concrete member. (A) is a cross-sectional view showing the joint-cap combined body attached to the concrete formwork with a male screw member, and (B) is a cross-sectional view showing concrete being poured into the concrete formwork. [Figure 9] It is a continuation of the manufacturing procedure of the precast concrete member. (A) is a cross-sectional view showing the male screw member removed, and (B) is a cross-sectional view showing the concrete formwork removed. [Figure 10] It is a continuation of the manufacturing procedure of the precast concrete member. (A) is a cross-sectional view showing the cap member removed, and (B) is a cross-sectional view of the precast concrete member in which screw studs protrude from the embedded joint member. [Figure 11] It is an enlarged cross-sectional view of FIG. 8(A). [Figure 12] It is an enlarged cross-sectional view of FIG. 8(B). [Figure 13] It is an enlarged cross-sectional view of FIG. 9(A). [Figure 14] It is an enlarged cross-sectional view of FIG. 9(B). [Figure 15] It is an enlarged cross-sectional view of FIG. 10(A). [Figure 16]This is an enlarged cross-sectional view of Figure 10(B). [Modes for carrying out the invention] 【0015】 Hereinafter, embodiments of the present invention will be described with reference to the drawings. Figure 15 is a cross-sectional view of the portion of a precast concrete member 1 manufactured by the manufacturing method of the present invention in which the joint member 10 is embedded. In this embodiment, as shown in Figure 1, the precast concrete member 1 is used as a beam member by connecting threaded reinforcing bars T to the embedded joint member 10 at the building construction site. Therefore, a joint member 10, as shown in Figure 2, is embedded in the precast concrete member 1 in order to allow the threaded reinforcing bar T to protrude. 【0016】 In this embodiment, the joint member 10 and the cap member 20 shown in Figures 3 and 4 are joined together to assemble the joint-cap assembly 40 shown in Figure 6(B). Then, as shown in Figure 8(A), the joint-cap assembly 40 is attached to the concrete formwork 30 using a male threaded member 42 that screws into the female thread 26 for connecting the male threaded member of the cap member 20, and the precast concrete member 1 is manufactured using the concrete formwork 30. 【0017】 First, with reference to Figure 2, the joint member 10 will be explained in detail. The joint member 10 is made of metal and is configured to include a cylindrical portion 12, as shown in Figure 2. The joint member 10 is a member used to connect threaded reinforcing bars T that protrude from the precast concrete member 1. The cylindrical portion 12 has an elongated shape with a regular hexagonal cross-section, and a female thread 16 for connecting threaded reinforcing bars is formed on its inner circumference, into which threaded reinforcing bars can be screwed. A female threaded opening 1602 for connecting threaded reinforcing bars is formed at one end 1202 in the axial direction of the cylindrical portion 12. As shown in Figure 1, the joint member 10 is embedded in the precast concrete member 1 so that the female threaded opening 1602 is exposed. 【0018】 A reinforcing bar 14 is integrally attached to the cylindrical portion 12, protruding from the other end 1204 in the axial direction of the cylindrical portion 12, which is located opposite the female screw opening 1602. The reinforcing bar 14 is a threaded reinforcing bar, which is attached to the other end 1204 of the cylindrical portion 12 by screwing it into the female thread 16 for connecting threaded reinforcing bars. In this embodiment, the reinforcing bar 14 is fixed to a predetermined position in the cylindrical portion 12 by welding 18. 【0019】 Furthermore, the joint member 10 is not limited to those described above; various conventionally known types that can be used to connect to threaded reinforcing bars T protruding from the precast concrete member 1 are also applicable. For example, the joint member 10 may consist only of the cylindrical portion 12, or a rod or the like may be fixed to the cylindrical portion 12 instead of the reinforcing bar 14. 【0020】 Next, the cap member 20 will be described with reference to Figures 3, 4, and 6. The cap member 20 is made of metal and, as shown in Figure 6, connects to the female thread 16 for connecting threaded reinforcing bars of the joint member 10, and is a member that closes the female thread opening 1602. As shown in Figures 3 and 4, the cap member 20 is configured to include a male threaded portion 22 for cap attachment and a lid portion 24. The male threaded portion 22 for cap attachment is cylindrical and has a male thread 2202 with an outer diameter that screws into the female thread 16 for connecting threaded reinforcing bars formed on its outer circumference. 【0021】 The cover portion 24 is an annular plate-shaped member provided at the axial end of the male threaded portion 22 for cap attachment, and as shown in Figure 6(B), it closes the female threaded opening 1602 when the male threaded portion 22 for cap attachment is screwed into the female threaded portion 16 for connecting the threaded reinforcing bars of the joint member 10. As shown in Figure 4, the outer diameter of the lid portion 24 is larger than the outer diameter of the male threaded portion 22 for cap attachment. Furthermore, as shown in Figure 6(B), the lid portion 24 is formed with a larger profile than the cylindrical portion 12 when viewed from the axial direction of the female thread 16 for connecting threaded reinforcing bars of the joint member 10, with the male thread portion 22 for attaching the cap of the cap member 20 connected to the female thread 16 for connecting threaded reinforcing bars of the joint member 10. In this embodiment, since the profile of the cylindrical portion 12 is a regular hexagon, the lid portion 24 is formed in a circular shape with a profile larger than that hexagon. 【0022】 The cap member 20 penetrates the center of the lid portion 24 and extends from the lid portion 24 to the male threaded portion 22 for cap attachment. Regardless of the size of the outer diameter of the male threaded portion 22 for cap attachment, a female thread 26 for connecting the male threaded member is formed with an inner diameter of a predetermined value. The female thread 26 for connecting the male thread member is designed to accommodate a predetermined male thread member 42 (Figure 11). In this embodiment, for example, the female thread 26 for connecting the male thread member is designed to accommodate an M6 (JIS standard) male thread member 42. 【0023】 As shown in Figures 3(A) and 4(B), a rotational locking portion 28 for rotating the lid portion 24 is formed on the outer end surface 2402 of the lid portion 24, which is located opposite the male threaded portion 22 for cap attachment. The outer end surface 2402 is formed as a flat surface. The locking portion 28 for rotational operation is formed by a pair of opposing grooves that are rectangular in shape and extend radially outward from the female thread 26 for connecting the male thread member on the diameter of the female thread 26 for connecting the male thread member of the lid portion 24. 【0024】 As shown in Figure 1, when a threaded reinforcing bar T is attached to the precast concrete member 1, the joint member 10 is provided with a female thread 16 for connecting the threaded reinforcing bar T. The cap member 20 is provided with a male threaded portion 22 for attaching the cap, which connects to the female thread 16 for connecting the threaded reinforcing bar of the joint member 10. On the other hand, the inner diameter of the female thread 26 for connecting the male thread member provided on the cap member 20, the outer diameter of the male thread member 42, and the rotational locking portion 28 provided on the outer end surface 2402 of the lid portion 24 are always predetermined dimensions, regardless of the outer diameter of the threaded reinforcing bar T used. 【0025】 Next, with reference to Figure 5, the concrete formwork 30 for forming the precast concrete member 1 will be described. The concrete formwork 30 is composed of a rectangular parallelepiped with an open top, and its cross-section is U-shaped. In this embodiment, the steel plate 32 that constitutes the side surface of the concrete formwork 30 is provided with a male screw member insertion hole 34 through which a male screw member 42 having a male thread that can be screwed into the female thread 26 for connecting the male screw member of the cap member 20 can be inserted. Furthermore, since the outer diameter of the male threaded member 42 is always formed to a predetermined value regardless of the outer diameter of the threaded reinforcing bar T used, the inner diameter of the male threaded member insertion hole 34 is also formed to a predetermined value. Although the concrete formwork 30 in this embodiment is made of steel plate, it may be made of other materials such as wood, as long as it is possible to pour concrete into it and to provide holes for inserting male screw members. Furthermore, the number and position of the holes for inserting male screw members are arbitrary and are determined according to the precast concrete member 1 being manufactured. 【0026】 Next, with reference to Figures 6 to 16, the manufacturing procedure for producing the precast concrete member 1 in which the joint member 10 of this embodiment is embedded will be described. First, as shown in Figures 6(A) and (B), the joint-cap assembly 40 is assembled from the joint member 10 and the cap member 20. That is, as shown in Figure 6(A), with one end 1202 of the cylindrical portion 12 of the joint member 10 and the male threaded portion 22 for cap attachment of the cap member 20 facing each other, the male threaded portion 22 for cap attachment of the cap member 20 is inserted while screwing it into the female thread 16 for connecting threaded reinforcing bars of the joint member 10. Then, as shown in Figure 6(B), the male threaded portion 22 for cap attachment of the cap member 20 is connected to the female threaded portion 16 for connecting threaded reinforcing bars of the joint member 10, and the female threaded opening 1602 is closed with the cover portion 24 to form a joint-cap assembly 40. Furthermore, by closing the female thread opening 1602 with the cover portion 24, it is possible to prevent concrete from flowing into the female thread 16 for connecting the threaded reinforcing bars of the joint member 10 during concrete pouring. 【0027】 Next, as shown in Figure 7(A), a male screw member insertion hole 34 is formed at a predetermined position in the steel plate 32 that constitutes the side surface of the concrete formwork 30, allowing the insertion of the male screw member 42. Then, as shown in Figure 7(B), the outer end surface 2402 of the cover portion 24 is brought into contact with the inner surface 3202 of the steel plate 32 that constitutes the inner surface of the concrete formwork 30, coaxially with the male screw member insertion hole 34, and around the male screw member insertion hole 34. 【0028】 Next, as shown in Figures 8(A) and 11, the male threaded member 42 (M6 bolt) inserted through the male threaded member insertion hole 34 from the outer surface of the concrete formwork 30 is screwed into the female thread 26 for connecting the male threaded member, thereby sandwiching the steel plate 32 between the lid 24 of the cap member 20 and the head of the male threaded member 42, and attaching the joint-cap assembly 40 to the inner surface 3202 of the steel plate 32. Once the joint-cap assembly 40 is attached to the concrete formwork 30, concrete C is poured into the concrete formwork 30 as shown in Figures 8(B) and 12, thereby manufacturing the precast concrete member 1 inside the concrete formwork 30. 【0029】 Once the predetermined time has elapsed and the concrete C has hardened, and the precast concrete member 1 has been manufactured, the male screw member 42 is removed from the female screw 26 for connecting the male screw member, as shown in Figures 9(A) and 13. Then, as shown in Figures 9(B) and 14, the precast concrete member 1 is removed from the concrete formwork 30 by removing the concrete formwork 30. Furthermore, as shown in Figures 10(A) and 15, the cap member 20 is removed from the female thread 16 for connecting threaded reinforcing bars of the joint-cap assembly 40 embedded in the precast concrete member 1. The cap member 20 can be easily removed from the joint-cap assembly 40 by engaging a tool such as a flathead screwdriver with the rotational locking part 28 (see Figure 14) and rotating it. This completes the production of the precast concrete member 1 with the joint member 10 embedded. 【0030】 Subsequently, the precast concrete members 1 shown in Figures 10(A) and 15 are transported to the construction site, and when concrete jointing work is performed, as shown in Figures 10(B) and 16, threaded reinforcing bars T are screwed into the female threaded opening 1602 of the joint member 10 embedded in the precast concrete member 1, thereby connecting the threaded reinforcing bars T to the joint member 10. This results in a precast concrete member 1 with the threaded reinforcing bar T shown in Figure 1 protruding from it. 【0031】 As described above, according to this embodiment, a cap member 20 is provided that screws onto the female thread 16 for connecting threaded reinforcing bars of the joint member 10, and the cap member 20 is provided with a female thread 26 for connecting a male threaded member, which is formed with an inner diameter of a predetermined value regardless of the size of the female thread 16 for connecting threaded reinforcing bars of the joint member 10. Therefore, the joint member 10 can be used as a male threaded member 42 for fixing it to the steel plate 32 of the concrete formwork 30, regardless of the size of the outer diameter of the threaded reinforcing bar T that protrudes from the precast concrete member 1 via the joint member 10, and a predetermined outer diameter can be used. In addition, the inner diameter of the male threaded member insertion hole 34 provided in the steel plate 32 of the concrete formwork 30 can be formed to a predetermined inner diameter regardless of the size of the outer diameter of the threaded reinforcing bar T that protrudes from the precast concrete member 1 via the joint member 10. Therefore, it is no longer necessary to prepare male threaded members 42 with different outer diameters each time to accommodate the different outer diameters of the threaded reinforcing bars T that protrude from the precast concrete member 30 via the joint member 10. Furthermore, it is no longer necessary to redrill male threaded member insertion holes 34 with different inner diameters in the steel plate 32 of the concrete formwork 30 each time. This makes it possible to easily manufacture the precast concrete member 1 with the joint member 10 embedded, resulting in a manufacturing method for the precast concrete member 1 that is advantageous in shortening manufacturing time and reducing costs. 【0032】 In other words, the outer diameter of the threaded reinforcing bar T protruding from the precast concrete member 1 is not a uniform value because the dimensions are selected to match the cross-sectional area and length of the concrete member that will be newly poured and integrated with the precast concrete member 1. In this embodiment, if the outer diameter of the threaded reinforcing bars T is different, a joint member 10 is manufactured with an inner diameter of the female thread 16 for connecting the threaded reinforcing bars formed to match the difference. Furthermore, a cap member 20 is manufactured to be connected to this joint member 10. When manufacturing this cap member 20, the inner diameter of the female thread 26 for connecting the male thread member provided on the cap member 20 and the outer diameter of the male thread member 42 are always formed to a constant value, regardless of the outer diameter of the threaded reinforcing bar T. In other words, even if a joint member 10 with a different inner diameter of the female thread 16 for connecting threaded reinforcing bars is used, the joint member 10 can be attached to the inner surface 3202 of the concrete formwork 30, which is provided with a male thread insertion hole 34 through which a predetermined male thread member 42 can be inserted, via the cap member 20 using the predetermined male thread member 42. Therefore, the male screw member insertion hole 34 and the male screw member 42 can be standardized, which is advantageous in easily manufacturing the precast concrete member 1 in which the joint member 10 is embedded, shortening manufacturing time and reducing costs. 【0033】 Furthermore, the locking portion 28 for rotational operation is formed in a predetermined shape regardless of the size of the outer diameter of the male threaded portion 22 for cap attachment. Therefore, it is not necessary to prepare a tool each time to accommodate the different sizes of outer diameters of the threaded reinforcing bars T that protrude from the precast concrete member 1 via the joint member 10. Therefore, the cap member 20 can be attached to and removed from the joint member 10 with a single tool, which is advantageous in improving work efficiency for the manufacturing of the precast concrete member 1. 【0034】 Furthermore, with the male threaded portion 22 for cap attachment of the cap member 20 connected to the female threaded portion 16 for connecting threaded reinforcing bars of the joint member 10, the cover portion 24 is formed with a larger outline than the cylindrical portion 12 when viewed from the axial direction of the female threaded portion 16 for connecting threaded reinforcing bars. Therefore, it is advantageous in manufacturing a visually appealing precast concrete member 1, without producing a precast concrete member 1 in which the concrete portion filled on the outside of the lid 24 easily breaks, or an incomplete precast concrete member 1 with a gap on the outside of the lid 24. Furthermore, this is advantageous for stably attaching the joint-cap assembly 40 to the inner surface 3202 of the concrete formwork 30. 【0035】 Furthermore, the cap member 20 includes a male threaded portion 22 for cap attachment, formed with an outer diameter that screws into the female thread 16 for connecting threaded reinforcing bars, and a lid portion 24 provided at the axial end of the male threaded portion 22 for cap attachment, with an outer diameter larger than the outer diameter of the male threaded portion 22. A female thread 26 for connecting the male threaded member is provided, which penetrates the lid portion 24 and extends from the lid portion 24 to the male threaded portion 22 for cap attachment, and has an inner diameter of a predetermined value regardless of the size of the outer diameter of the male threaded portion 22. In addition, a rotational locking portion 28 for rotating the lid portion 24 is provided on the outer end surface 2402 of the lid portion 24, which is located opposite the male threaded portion 22 for cap attachment. Therefore, for example, when attaching a joint member 10 having a female thread 16 for connecting threaded reinforcing bars to a steel plate 32 of a concrete formwork 30, a male threaded member 42 with a predetermined outer diameter can be used regardless of the size of the inner diameter of the female thread 16 for connecting threaded reinforcing bars. In addition, the inner diameter of the hole 34 for inserting the male threaded member provided in the steel plate 32 of the concrete formwork 30 can be formed with a predetermined inner diameter regardless of the size of the inner diameter of the female thread 16 for connecting threaded reinforcing bars. Therefore, it is no longer necessary to prepare male threaded members 42 with different outer diameters each time to correspond to the size of the outer diameter of the threaded reinforcing bars T that protrude from the precast concrete member 1 via the joint member 10, and it is also no longer necessary to redrill male threaded member insertion holes 34 with different inner diameters in the steel plate 32 of the concrete formwork 30 each time. This makes it easy to manufacture the precast concrete member 1 with the joint member 10 embedded, which is advantageous in shortening manufacturing time and reducing costs. 【0036】 In other words, the cap member 20 is provided with a female thread 26 for connecting a male thread member into which a predetermined male thread member 42 is screwed. Therefore, the joint member 10 can be attached to the inner surface 3202 of the concrete formwork 30, which is provided with a male thread member insertion hole 34 through which the predetermined male thread member 42 can be inserted, via the cap member 20 using the predetermined male thread member 42. Therefore, the male screw member insertion hole 34 and the male screw member 42 can be standardized, which is advantageous in easily manufacturing the precast concrete member 1 in which the joint member 10 is embedded, shortening manufacturing time and reducing costs. Furthermore, the cap member 20 can be easily removed by engaging a tool such as a flathead screwdriver with the rotational locking part 28 and rotating it. [Explanation of symbols] 【0037】 1. Precast concrete member 10 Joint members 12 Cylinder 14 Reinforcement bars 16. Female thread for connecting threaded reinforcing bars. 1602 Male thread opening 18 Welding 20 Cap component 22 Male threaded section for cap attachment 24 Lid 2402 Outer end face 28 Locking part for rotational operation 30 Concrete formwork 32 Steel plate 34 Male threaded member insertion hole 40 Joint / Cap Connectors 42 Male threaded member C Concrete T-shaped threaded reinforcing bars

Claims

[Claim 1] A method for manufacturing a precast concrete member in which a joint member for attaching threaded reinforcing bars is embedded, The joint member comprises an elongated cylindrical portion having a female thread for connecting threaded reinforcing bars formed on its inner circumference into which the threaded reinforcing bars can be screwed, and a female thread opening for the female thread for connecting threaded reinforcing bars formed at one end of the cylindrical portion in the axial direction, A cap member comprising: a male threaded portion for attaching a cap, formed with an outer diameter that screws into the female thread for connecting threaded reinforcing bars; a lid portion provided at the axial end of the male threaded portion for attaching a cap, which closes the female thread opening when the male threaded portion for attaching a cap is screwed into the female thread for connecting threaded reinforcing bars; a female thread for connecting a male threaded member, which penetrates the lid portion and extends from the lid portion to the male threaded portion for attaching a cap, and is formed with an inner diameter of a predetermined value regardless of the size of the outer diameter of the male threaded portion for attaching a cap; and a locking portion for rotational operation of the lid portion, formed on the outer end surface of the lid portion opposite to the male threaded portion for attaching a cap; A male screw member having a male thread that can be screwed into the female thread for connecting the male screw member is provided, A joint-cap assembly is provided in which the female thread for connecting the threaded reinforcing bars of the joint member is connected to the male thread for attaching the cap of the cap member, and the female thread opening is closed with the lid. A hole for inserting the male screw member is provided in the plate material that constitutes the concrete formwork, allowing the male screw member to be inserted. The joint-cap assembly is attached to the inner surface of the plate material constituting the inner surface of the concrete formwork by screwing the male screw member inserted through the male screw member insertion hole into the female screw for connecting the male screw member, with the outer end surface of the lid abutting against the periphery of the male screw member insertion hole, and the male screw member being screwed into the female screw for connecting the male screw member. Concrete is poured into the concrete formwork to manufacture the precast concrete member inside the concrete formwork, and after manufacturing, the male screw member is removed from the female screw for connecting the male screw member to remove the precast concrete member from the concrete formwork. By engaging a tool with the aforementioned locking mechanism for rotation and rotating it, the cap member is removed from the joint-cap assembly. A method for manufacturing precast concrete members, characterized by the following: [Claim 2] The locking portion for rotation is formed in a predetermined shape, regardless of the size of the outer diameter of the male thread portion for cap attachment. A method for manufacturing a precast concrete member according to claim 1, characterized in that it is a method for manufacturing a precast concrete member. [Claim 3] With the male threaded portion for cap attachment of the cap member connected to the female threaded portion for connecting the threaded joint reinforcing bar of the joint member, the lid portion is formed with a larger outline than the cylindrical portion when viewed from the axial direction of the female threaded portion for connecting the threaded joint reinforcing bar. A method for manufacturing a precast concrete member according to claim 1, characterized in that it is a method for manufacturing a precast concrete member. [Claim 4] A male threaded portion for attaching a cap, which has a male thread formed along its entire length in the longitudinal direction to screw into a female thread for connecting threaded reinforcing bars, A lid portion is provided at the longitudinal end of the male threaded portion for cap attachment, with an outer diameter larger than the outer diameter of the male threaded portion for cap attachment. A female thread is provided that extends from the lid portion through to the male thread portion for cap attachment and is formed with an inner diameter of a predetermined value, regardless of the size of the outer diameter of the male thread portion for cap attachment. A rotational locking portion for rotating the lid is formed on the outer end surface of the lid, opposite to the male threaded portion for attaching the cap, A cap member characterized by comprising the following features. [Claim 5] The locking portion for rotation is formed in a predetermined shape, regardless of the size of the outer diameter of the male thread portion for cap attachment. The cap member according to claim 4, characterized in that it is a cap member as described in claim 4.

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