JP5406698B2 - Connecting tool for PC formwork - Google Patents

Description

  The present invention relates to a connector for a PC formwork for connecting a precast concrete board (PC board) constituting a concrete placement form.

  Conventionally, in the construction of reinforced concrete structures such as walls, a method has been widely used in which a formwork supported by a support is temporarily installed, concrete is driven into the formwork, and then the formwork and the support are removed. . Such a construction method requires temporary installation and removal of the formwork and the support work, and therefore the construction period becomes longer and the construction cost becomes higher. In addition, as a labor-saving construction method, a method has been known in which a formwork is assembled on site using precast concrete plates of factory products, and then concrete is poured into the formwork and integrated, and removal of the formwork is omitted ( For example, see Patent Document 1). However, such a labor-saving construction method still requires a support work, and it cannot be said that the labor saving is sufficient. In addition, this labor-saving construction method involves assembly work performed by the worker inside the mold, and because the reinforcing bars are assembled inside the mold and it is difficult for the worker to enter, the construction is not easy.

JP-A-8-333829

  This invention solves the said problem, and it aims at making construction easy while making a support work unnecessary in the construction of the concrete placement formwork using a PC board.

  In order to achieve the above object, the invention of claim 1 is a connecting device for PC formwork for connecting a plurality of precast concrete plates (hereinafter referred to as PC plates) to form a concrete casting formwork, Each of the PC plates erected vertically and horizontally so as to form a wall surface, and a bolt-shaped connected metal fitting that has a shaft portion and a head, and protrudes from the back corner portion of each of the PC plates. Connecting brackets that are connected to each other at the corners via the connected brackets, and the coupling brackets are inclined to the plate member that is in contact with the back side of the PC plate and the periphery of the plate member. It has a plurality of notches that are open, and the shafts of the metal fittings to be connected are inserted into the notches through the openings, thereby connecting the PC plates.

Furthermore, the connection fitting has a protrusion at the edge of the notch that prevents the shaft portion of the connected fitting inserted into the notch from being pulled out to the notch opening side. It is.

According to a second aspect of the present invention, in the connecting device for a PC formwork according to the first aspect , the connecting bracket is provided for maintaining a space between the PC plates erected on the plate-like member so as to face each other. A separator is penetrated and one end of the separator is fixed.

According to a third aspect of the present invention, the connecting device for the PC formwork according to the first or second aspect is used, and the connection is made to the connected metal fitting protruding from the upper corner portion of the upright PC plate. It is an assembling method of a concrete placing form, characterized in that a metal fitting is attached and the PC plates are connected to each other by standing up so that another PC plate is dropped onto the upper end of the PC plate.

  According to the first aspect of the present invention, since the PC plates constituting the mold are connected by the connector, a support work for supporting the mold is not required. In addition, the bolts to be connected to the PC plate in advance before the connection work are inserted into the notches of the connection bracket so that the PC plates are connected to each other. There is no need to attach the connected metal fittings, and the construction of the mold becomes easy.

Moreover, since the shaft portion inserted into the notch is locked by the convex portion, it is prevented from being pulled out to the notch opening side.

According to the second aspect of the present invention, when concrete is poured into a mold formed of a PC plate, a side pressure is applied to the PC plate, but the PC plates facing each other are connected via the connecting fitting and the separator. It has high formwork strength.

According to the invention of claim 3, the PC plates can be easily connected to each other by dropping the PC plate from the outside of the mold, and the construction of the mold is facilitated.

Sectional drawing in the middle of construction of the concrete placement formwork which connects a PC board using the connector for PC formwork which concerns on embodiment of this invention. Sectional drawing of the connection tool. The front view which looked at the same connector from the mold inner side. The front view of the connection metal fitting of the connection tool. (A) is a side view of the connection fitting, (b) is an end view taken along line AA in FIG. 4, and (c) is an end view taken along line BB in FIG. The front view of the notch in the connection metal fitting. (A) is a front view of the connection fitting having a notch inclined to the right, and (b) is a front view of the connection fitting having a notch inclined to the left. The front view which looked at the above-mentioned concrete placement formwork from the formwork inside. (A) is a top view of the connection metal fitting for the lowest level plane part in the concrete placement mold, (b) is a side view of the connection metal fitting, (c) is a front view of the connection metal fitting. (A) is a top view of the connection metal fitting for uppermost plane parts, (b) is a side view of the connection metal fitting, (c) is a front view of the connection metal fitting. (A) is a top view of the connection metal fitting for the lowermost corner part, (b) is a side view of the connection metal fitting, and (c) is a front view of the connection metal fitting. (A) is a top view of the connecting bracket for the middle corner, (b) is a side view of the connecting bracket, and (c) is a front view of the connecting bracket. (A) is a top view of the connection metal fitting for uppermost corner parts, (b) is a side view of the connection metal fitting, and (c) is a front view of the connection metal fitting. The top view which looked at the middle step of the above-mentioned concrete placement form from the top. Sectional drawing of the said coupling metal fitting (for middle level plane parts) which attached the separator to the diagonal direction. The front view of the washer used for attachment of the separator.

  A connector for a PC formwork according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7A and 7B. As shown in FIG. 1, a connecting tool 1 for PC formwork (hereinafter referred to as a connecting tool) includes a connected metal fitting 2 and a connecting metal fitting 3, and includes a plurality of precast concrete plates 41 (hereinafter referred to as PC plates). Are used to form a concrete casting form 4 (hereinafter referred to as a formwork). After the reinforcing bars 6 are assembled on the concrete floor 5, the PC board 41 is connected by the connecting tool 1 as indicated by the white arrow, and the frame 4 is assembled by standing around the reinforcing bars 6. A separator 7 is provided between the connecting fittings 3 facing each other. The separator 7 is a rod-shaped formwork space holding material, and keeps the space between the PC plates 41 that are erected facing each other. After the formwork 4 is assembled, concrete is driven. The separator 7 receives the lateral pressure applied to the PC board 41 by the concrete driven into the mold 4. The concrete is hardened and integrated with the formwork 4 to produce a concrete structure such as a wall. The connector 1 and the separator 7 are left in the concrete.

  As shown in FIGS. 2 and 3, the to-be-connected bracket 2 is a bolt-shaped bracket having a shaft portion 21 and a head portion 22, and protrudes from each back side corner portion of the PC plate 41. The back side of the PC board 41 is the side on which concrete is driven. The connecting fitting 3 is a fitting that connects the PC plates 41 erected on the top, bottom, left, and right so as to form a wall surface via the to-be-connected fitting 2 at their corners. The connection fitting 3 includes a plate-like member 31 that is in contact with the back side of the PC plate 41 and a plurality of cutouts 32 that open obliquely at the periphery of the plate-like member 31. The part 21 is inserted into the notch 32 through the opening, thereby connecting the PC boards 41 to each other.

  The PC board 41 is a rectangular concrete board manufactured at a factory, and is used as a dam plate of the mold 4. The dam plate is a plate that prevents the concrete from flowing out and supports the lateral pressure of the concrete in the mold. The size of the PC board 41 is desirably about 3 to 4 cm in thickness of 50 cm square, for example, in order to make the size and weight (30 kg or less) that an on-site worker can have alone. The PC board 41 is not removed after the concrete is hardened, and constitutes the outer wall of the concrete structure. In order to improve the aesthetics of the concrete structure, the PC board 41 may be a PC board for a decorative mold having a concavo-convex pattern on the front wall surface. A cap nut 42 for screwing the connected metal fitting 2 is embedded in the back side corner of the PC plate 41 at the time of manufacture. The cap nut 42 is formed with a flange 43 so as not to fall out of the PC plate 41. The PC board 41 is transported to the site in a flat state where the connected fitting 2 is not projected. For this reason, the several PC board 41 can be piled up mutually, and can be conveyed efficiently.

  The to-be-connected metal fitting 2 is, for example, a steel bolt, has a shaft portion 21 and a head portion 22 having a diameter larger than that of the shaft portion 21, and is screwed to a cap nut 42 on the site and attached to the PC plate 41. It is done. The length of the shaft portion 21 is set so that a predetermined gap 23 is formed between the head 22 and the PC plate 41 when the metal fitting 2 is attached to the PC plate 41. The plate-like member 31 of the connection fitting 3 is fitted into the gap 23. In order to facilitate the fitting of the plate member 31, the surface of the head portion 22 on the shaft portion 21 side may be tapered so that the gap 23 expands in the radial direction.

  As shown in FIGS. 4 and 5A, 5B, and 5C, the connecting fitting 3 is obtained by pressing an iron plate, and includes a substantially rectangular plate-like member 31. The plate-like member 31 has notches 32 at the corners of the upper side and the lower side in a state where the plate-like member 31 is in contact with the PC plate 41. The plate-like member 31 is formed with a peripheral rib 33 for reinforcement at the periphery where the notch 32 is not opened.

  The plate-like member 31 is formed in a substantially truncated cone shape at the center, and has a recess 37 on the side abutting against the PC plate 41. Have The separator 7 has a thread at its end, the end is passed through the hole 35, and the plate-like member 31 is sandwiched between the two nuts 71 and 72 screwed into the end so that the connecting metal 3 is attached to the separator 7. Fixed. One nut 71 is accommodated in the recess 37. The hole 36 is used for attaching the separator 7 to the plate-like member 31 in an oblique direction.

  As shown in FIG. 6, the notch 32 has a vertically long substantially U shape, is formed so that the longitudinal direction is inclined with respect to the vertical direction, and opens obliquely at the periphery of the plate-like member 31. Yes. The angle θ formed by the longitudinal direction of the notch 32 with respect to the vertical direction is about 20 °. The width W perpendicular to the longitudinal direction of the notch 32 is larger than the diameter of the shaft portion 21 of the connected metal fitting 2 and smaller than the diameter of the head portion 22. The shaft portion 21 of the connected metal fitting 2 is inserted into the notch 32. The connecting fitting 3 has convex portions 34a and 34b that prevent the shaft portion 21 (shown by a two-dot chain line) of the connected fitting 2 in a state of being inserted into the notch 32 from being pulled out to the notch 32 opening side. , 34 c (generally, 34) at the edge of the notch 32. On the edge of the notch 32 obliquely 45 ° above (in the directions of arrows F1 and F2) from the center of the shaft portion 21 inserted into the notch 32 by the convex portions 34a and 34c, Corresponding arcuate portions 34aR and 34cR are formed (shaded portions).

  The center locus of the shaft portion 21 when the shaft portion 21 of the metal fitting 2 is inserted into the notch 32 is indicated by an arrow T. Since the notch 32 is formed so that the longitudinal direction is inclined, the shaft portion 21 is inserted into the notch 32 while moving obliquely downward. For this reason, since the PC board 41 is connected to the other PC boards 41 so as to drop obliquely downward, it is possible to avoid interference between the PC boards 41 adjacent in the lateral direction during the connection operation. As shown in FIGS. 7A and 7B, two types of connecting metal fittings 3 having a mirror image relationship are used. The connecting bracket 3 in which the longitudinal direction of the notch 32 is inclined to the right is used to connect another PC plate 41 to the right of the PC plate 41 erected first (see FIG. 7A). The connection fitting 3 in which the longitudinal direction of the notch 32 is inclined to the left is used to connect another PC plate 41 to the left side of the PC plate 41 erected in advance (see FIG. 7B).

  The shaft portion 21 inserted in the notch 32 is held in the notch 32 by the weight of the PC plate 41. When the concrete is driven into the mold 4, a side pressure is applied to the PC plate 41, and the shaft portion 21 inserted into the notch 32 is pulled out to the opening side of the notch 32 (FIGS. 6 and 7). A force in the direction of arrows F1 and F2 in FIG. When the shaft portion 21 receives this force and moves in the notch 32, the shaft portion 21 is locked by the convex portion 34, particularly the convex portions 34a and 34c, and engages with the arc portions 34aR and 34cR. Removal is prevented.

  Using the connecting tool 1 configured as described above, an on-site worker can connect the connecting metal fitting 2 to the connected metal fitting 2 protruding from the upper corner portion of the upright PC plate 41 in assembling the mold 4. 3 is attached and the PC plates 41 are connected to each other by being erected so that another PC plate 41 is dropped onto the upper end of the PC plate 41.

  Since the connecting tool 1 connects the PC plates 41 constituting the mold 4 before the concrete is driven into the mold 4 and before the poured concrete is hardened, the mold 4 is Supporting support work becomes unnecessary. Since the connector 1 is attached to the back side of the PC board 41, it remains in the concrete even after the poured concrete is hardened, and does not affect the appearance of the concrete structure. In addition, since the connecting tool 1 connects the PC plates 41 by inserting the bolt-shaped connecting metal fitting 2 into the notch 32 of the connecting metal fitting 3, the connecting metal fitting 2 is preliminarily PC-connected before the connection work. It is attached to the plate 41, so that it is not necessary for an operator to enter and attach the inside of the mold, and the construction of the mold 4 becomes easy. By using such a connector 1, the PC plates 41 can be easily connected to each other by dropping the PC plate 41 from the outside of the mold, and the construction of the mold 4 is facilitated.

  Moreover, the connecting metal fitting 3 attaches the separator 7 through the holes 35 and 36 and receives the lateral pressure applied to the PC plate 41 by the concrete by the separator 7 (see FIGS. 4 and 5C). Increasing the height of the mold 4 increases the side pressure, but receiving the side pressure with the separator 7 eliminates the need for receiving side pressure at the support. The mold 4 has high strength because the PC plates 41 facing each other are connected via the connection fitting 3 and the separator 7.

  FIG. 8 shows the arrangement of the connecting metal fittings in the mold 4. The connection fitting 3 described above is a connection fitting for the middle plane portion that planarly connects the four PC plates 41 in the middle stage of the mold 4. For the connection of the PC plate 41, in addition to the connecting bracket 3 for the middle flat portion, the connecting bracket 8a for the lowermost flat portion, the connecting bracket 8b for the uppermost flat portion, and the corner for the lowermost step portion are used. The connecting bracket 8c, the connecting bracket 8d for the middle corner, and the connecting bracket 8e for the uppermost corner are used.

  The lowermost plane connecting part 8 a is a base metal that connects two PC plates 41 in a planar manner at the lower corner part and stands on the concrete floor 5. The connection bracket 8b for the uppermost plane portion is a joint hardware for connecting the two PC plates 41 in a planar manner at the upper corner portion. The lowermost corner metal fitting 8c is a base metal that stands upright on the concrete floor 5 by connecting two PC boards 41 at a right angle at the lower corner at the corner of the mold 4. is there. The connecting bracket 8d for the middle corner is a joint metal that connects the four PC plates 41 at a right angle on the side and in a plane on the top and bottom. The connection bracket 8e for the uppermost corner is a joint metal that connects the two PC plates 41 at a right angle at the upper corner.

  As shown in FIGS. 9 (a), 9 (b), and 9 (c), the connecting bracket 8a for the lowermost plane portion is formed in an L shape in a side view and includes a bottom plate 81a and a side plate 82a. The bottom plate 81a has a round hole 83a for passing a bolt, and is fixed to the concrete floor plate with a bolt. A cap nut to which the bolt is screwed is embedded in the concrete floor board in advance. The bottom plate 81a may be fixed to the concrete floor surface with an anchor bolt without using the cap nut. The side plate 82a has two notches 32 that open obliquely at the periphery of the upper portion thereof. The shape of the notch 32 is the same as that of the notch 32 of the connecting member 3 for the middle flat surface portion, and the inclination in the longitudinal direction is appropriately selected to be inclined to the left and right (the same applies to the connecting members 8b to 8e). ). The connection fitting 8a has a peripheral rib 85a and an intermediate rib 86a for reinforcement.

  As shown in FIGS. 10 (a), (b), and (c), the uppermost flat plate connecting bracket 8b is formed in an inverted L shape in a side view and includes a side plate 81b and a top plate 82b. The side plate 81b has two notches 32 that open obliquely at the periphery of the lower portion thereof. The top plate 82c has a round hole 83b for hooking a hook separator (not shown). The connection fitting 8b has a peripheral rib 85b and an intermediate rib 86b for reinforcement.

  As shown in FIGS. 11 (a), 11 (b), and 11 (c), the connecting bracket 8c for the lowermost corner includes a bottom plate 81c and two side plates 82c and 83c that are orthogonal to each other. The bottom plate 81c has a round hole 84c through which a bolt passes, and is fixed to the concrete floor plate with a bolt. Each side plate 82c, 83c has a notch 32 that opens obliquely at the periphery of the upper portion thereof. The connection fitting 8c has a peripheral rib 85c and an intermediate rib 86c for reinforcement.

  As shown in FIGS. 12A, 12B, and 12C, the connecting bracket 8d for the middle corner portion is formed in an L shape in a plan view and includes two side plates 81d and 82d. Each of the side plates 81d and 82d has a notch 82 that opens obliquely at the upper peripheral edge thereof, and a round hole 83d for bolting to the PC plate 41 at the lower portion. The connection fitting 8d has a peripheral rib 85d and an intermediate rib 86d for reinforcement.

  As shown in FIGS. 13A, 13B, and 13C, the connecting bracket 8e for the uppermost corner is formed in an L shape in a plan view and includes two side plates 81e and 82e. Each of the side plates 81e and 82e has a notch 32 that opens obliquely at the periphery of the lower portion thereof. The connection fitting 8e has a peripheral rib 85e and an intermediate rib 86e for reinforcement.

  The mold 4 is assembled by connecting the PC plates 41 in order from the bottom to the top using such connecting fittings 3, 8a, 8b, 8c, 8d, and 8e (see FIG. 8).

  FIG. 14 shows the construction order of the corners of the mold 4. First, the right wall surface in the figure in the mold 4 is formed. One stage of the PC plate 41 is erected on the concrete floor surface in the construction sequence indicated by the arrow C1. Next, upper and lower wall surfaces are formed in FIG. The PC board 41 is erected in order from the right to the left on the concrete floor surface in the construction order indicated by the arrow C2. Next, the left wall is formed (not shown).

  Another PC plate is further erected on the upper end of the PC plate 41 erected on the concrete floor as described above. The construction order is the order of arrows C1 and C2. In the construction of the portion indicated by the arrow C2, the separator 7 is attached so as to connect the connecting fittings 3 facing each other. Then, the separator 7 which connects the connection metal fittings 3 diagonally is attached. Since the work for attaching the separator 7 is performed for each stage, it is performed within the reach of the worker's hand from the outside of the mold 4, and it is not necessary for the worker to enter the inside of the mold 4. Another PC plate 41 is further erected on the upper end of the erected PC plate 41 one by one according to the required height of the mold 4.

  The attachment structure of the separator 7 which connects the connection metal fittings 3 diagonally is demonstrated with reference to FIG.15 and FIG.16. As shown in FIG. 15, the bolt 73 is inserted into the hole 36 through the washer 38 from the concave portion 37 side of the connection fitting 3, and the shaft portion of the bolt 73 and the end portion of the separator 7 are fastened by the long nut 74. A turnbuckle may be used instead of the long nut 74. The washer 38 is, for example, an iron plate bent into a shape along the inner surface of the concave portion 37, and one having three round holes 39 as shown in FIG.

  In addition, this invention is not restricted to the structure of said embodiment, A various deformation | transformation is possible in the range which does not change the summary of invention. For example, the separator 7 may have a steel rod having a thread at its end and a steel wire at the middle. Thereby, a plurality of separators 7 can be made to intersect plane easily.

1 Connector for PC formwork (connector)
2 Connected fitting 21 Shaft portion 22 Head 3 Connecting fitting 31 Plate-like member 32 Notch 34 (34a, 34b, 34c) Convex portion 35, 36 Hole 4 Concrete placing formwork (formwork)
41 Precast concrete board (PC board)
7 Separator

Claims (3)

A connecting tool for PC formwork for connecting a plurality of precast concrete boards (hereinafter referred to as PC boards) to form a concrete casting formwork,
A bolt-shaped connected metal fitting protruding from the back corner of each of the PC plates and having a shaft and a head;
A connecting bracket for connecting each of the PC plates erected on the top, bottom, left and right so as to form a wall surface via the connected bracket at their corners,
The connecting metal fitting has a plate-like member that is in contact with the back side of the PC plate, and a plurality of notches that open obliquely at the periphery of the plate-like member, and the shaft portion of the connected metal fitting is the opening. The PC plates are connected by being inserted into the notch through ,
Furthermore, the connecting metal fitting has a convex portion at the edge of the notch that prevents the shaft portion of the connected metal fitting inserted into the notch from being pulled out to the notch opening side. A connector for PC formwork characterized by the above. The connecting fitting is in the plate-like member, it is penetrated separator for maintaining a distance to PC plates erected facing each other, according to claim 1, wherein the one end of the separator is fixed For PC formwork. Using the connecting device for PC formwork according to claim 1 or 2, the connecting metal fitting is attached to the connected metal fitting protruding from the upper corner portion of the standing PC plate, and the PC plate A method of assembling a concrete casting form, characterized in that the PC plates are connected to each other by standing up so that another PC plate is dropped on the upper end of the PC.

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