JP4831798B1 - Forming box for box cutting and method for punching the same - Google Patents

Abstract

The present invention provides a box forming mold and a method for cutting the same, in which irregularities are formed on the inner surface of the box extracting hole and the box forming mold can be easily pulled out from cast concrete.
A box forming mold for forming a recess in a cast concrete to be cast in a concrete mold that surrounds a side, and is suspended by a hanging bracket supported by the concrete mold. A support rod, a box-forming form body having rigidity fixed to the suspension support rod, an elastic covering provided so as to cover the outer periphery of the box-forming form body, and an outer periphery of the elastic covering It is characterized by being comprised from the resin sheet which has the unevenness | corrugation coat | covered by a part.
[Selection] Figure 6

Description

  The present invention relates to a box-forming mold for forming a recess in cast concrete to be cast in a concrete mold that surrounds the side, and a method for punching the same.

A conventional boxing formwork has a substantially cylindrical boxing formwork, in which a pair of mold pieces are connected by a tension spring, placed in a foundation forming formwork, and after the cast concrete is solidified, the cam member , And the box-forming molds are moved closer to each other by the urging force of the tension spring and separated from the cast concrete (hereinafter referred to as “Prior Art 1”, for example). (See Patent Document 1, page 4, FIG. 5).
However, in the prior art 1, since the concrete is integrated with the outer surface of the boxing mold and solidified, depending on the urging force of the tension spring, the outer surface of the boxing mold may be peeled off from the cast concrete. The boxing formwork still remains attached to the cast concrete, and a great pulling force and a large pulling force are required to pull out the boxing formwork against the resistance force attached to the cast concrete. There was a risk that work time would be required.

  In order to solve the problems of the prior art 1, the applicant of the present application is provided so as to cover the outer peripheral portion of the box-forming form body fixed to the suspension rod and having rigidity so as to cover the elastic cover, and further, the elastic cover A linear pressing body that deforms the elastic covering body in the direction of diameter reduction of the boxing mold body, and one end portion of the linear pressing body at a predetermined fastening position of the boxing mold body A suspension rod that is fixed to the elastic covering body and spirally wound upward along the outer peripheral portion of the elastic covering body, and fixes the box-extracting formwork body mounted with the elastic covering body and the linear pressing body, After the concrete placed in the concrete form is suspended and supported by a hanging metal fixture supported by the concrete form, and the concrete placed in the concrete form is solidified, the linear pressing body is placed above the box formwork main body. The elastic covering is deformed in the direction of the diameter reduction of the box body for box extraction, and is elasticated via the suspension rod. An application has been filed for a box-drawing formwork and a die-cutting method in which a box-drawing formwork main body to which a cover and a linear pressing body are attached has been pulled out (hereinafter referred to as “Prior Art 2”). (See Patent Document 2, FIGS. 6 and 7).

JP-A-5-79042 Japanese Patent No. 4607251

  Prior art 2 is an epoch-making invention in the sense of solving the problems of prior art 1, but is directed upward along the outer peripheral portion of the elastic covering member that is coated on the outer peripheral portion of the boxing formwork body. The linear pressing body is spirally wound, and after placing the concrete, the linear pressing body is pulled up above the boxing formwork body to deform the elastic covering in the direction of the diameter reduction of the boxing formwork body. Because the box body for pulling out the box with the elastic covering and the linear pressing body attached thereto is pulled out via the suspension rod, the linear pressing body is wound spirally around the outer periphery of the covering elastic covering And when pulling out the boxwork formwork main body, it is necessary to pull the linear pressing body above the boxwork formwork main body and reduce the diameter. It is a manual operation that requires skill, and after pulling out the box body for box extraction, loosen the linear pressing body appropriately, Only it is necessary to hold in the absence, there is a problem that the work is troublesome.

  The present invention is an improvement of the prior art 2 in which a resin sheet having projections and depressions is coated along the outer peripheral portion of an elastic covering coated on the outer peripheral portion of a box body for boxing, and after placing concrete, In the extraction of the extraction mold, first, only the box extraction mold main body is withdrawn, leaving the elastic cover and the resin sheet, and then the elastic cover and the resin sheet are withdrawn. It is an object of the present invention to provide a box forming mold and a method of punching the same, in which irregularities are formed on the inner surface of the box extracting hole and the box forming mold can be easily pulled out from the cast concrete without performing work. And

In order to solve the above-mentioned problems,
A box-forming form for forming a recess in the cast concrete to be cast in the concrete form surrounding the side,
A suspension rod supported by a suspension bracket supported by the concrete formwork, a boxing formwork body having rigidity fixed to the suspension rod, and an outer peripheral portion of the boxing formwork body. It is characterized by being comprised from the elastic coating body provided so that it might coat | cover, and the resin sheet which has the unevenness | corrugation further coat | covered on the outer peripheral part of the said elastic coating body.
According to this feature, a resin sheet having irregularities is interposed between the elastic covering covering the outer peripheral portion of the boxing formwork main body and the cast concrete, and the boxing hole of the cast concrete is formed by this resin sheet. An uneven surface can be formed on the inner surface of the steel, and by using this uneven surface, anchor concrete can be firmly embedded in the cast concrete by integrating the separate concrete to be cast into the box punching hole with the cast concrete. . In that case, like the prior art 2, in the operation | work which winds a linear press body helically, and the extraction of the boxing formwork main body, a linear pressing body is made above a boxing formwork main body. The work of raising and reducing the diameter is unnecessary, and the work can be greatly improved.
Further, since the elastic covering body has appropriate elasticity, it is possible to easily pull out the box-drawing formwork main body and to easily pull out the elastic covering body and the resin sheet.

The boxing formwork of the present invention is characterized in that the boxing formwork body has a circular cross section having a taper whose diameter gradually decreases from the upper side to the lower side.
According to this feature, it is possible to more easily pull the box extraction form body upward.

The boxing formwork of the present invention is characterized in that the boxing formwork body has a structure that can be extended in the vertical direction.
According to this feature, the vertical length of the boxing mold can be adjusted as appropriate according to the depth of the recess formed in the cast concrete.

The boxing mold according to the present invention is characterized in that the resin sheet having the unevenness is covered on the outer peripheral portion of the elastic covering body such that a gap is formed at both ends in the circumferential direction.
According to this feature, even if the outer peripheral shape of the elastic covering is tapered, there is no need to match both ends of the resin sheet in the circumferential direction, and there is no overlap between the resin sheets having irregularities. It is possible to cover the outer peripheral surface of the elastic covering body in a close contact state.
Further, when the elastic covering and the resin sheet are removed from the box punching hole, the pinch metal fitting is attached to the gap of the resin sheet and twisted inward in the radial direction, and the outer peripheral surface of the elastic covering and the resin sheet is casted into the concrete. Convenient to separate from.

In the boxing mold according to the present invention, the resin sheet having the unevenness is set at a position where the upper end is lower than the top edge of the cast concrete, and the lower end is fitted to the bottom of the boxing mold body and the elastic covering. It is set so that it may contact | abut with the upper end of the made cap.
According to this characteristic, it can form in a shape without an unevenness | corrugation in the top end of the casting concrete of a box punching hole. In addition, it is possible to prevent the cast concrete from entering from below between the box forming form main body and the elastic covering and between the elastic covering and the resin sheet.

The die cutting method of the box cutting form of the present invention is:
A die-cutting method for a box-drawing mold for forming a recess in the cast concrete to be cast in a concrete mold surrounding the side,
Provided to cover the outer peripheral portion of the box body for box extraction, which is fixed to the suspension rod and has rigidity, so as to cover the elastic covering, and further, the outer peripheral portion of the elastic covering is covered with a resin sheet having irregularities,
The suspension rod for fixing the box-extracting formwork body mounted with the elastic covering and the resin sheet is suspended in a suspension fitting supported by the concrete formwork and disposed in the concrete formwork. ,
After the concrete placed in the concrete mold is solidified, the box-drawing mold main body is lifted upward via the suspension support rod, and the elastic cover and the resin sheet are left to be pulled out. .
According to this feature, a resin sheet having irregularities is interposed between the elastic covering covering the outer peripheral portion of the boxing formwork main body and the cast concrete, and the boxing hole of the cast concrete is formed by this resin sheet. An uneven surface can be formed on the inner surface of the steel, and by using this uneven surface, anchor concrete can be firmly embedded in the cast concrete by integrating the separate concrete to be cast into the box punching hole with the cast concrete. . At that time, in order to pull out the box-forming form body while leaving the elastic covering and the resin sheet, as in the prior art 2, the work of winding the linear pressing body in a spiral shape, and the box-forming form body Therefore, the work of pulling up and reducing the diameter of the linear pressing body above the box main body for box extraction becomes unnecessary, and the work can be greatly improved.
Further, since the elastic covering body has appropriate elasticity, it is possible to easily pull out the box-drawing formwork main body and to easily pull out the elastic covering body and the resin sheet.

The die cutting method of the box cutting form of the present invention is:
After the box body for box extraction is pulled out, the elastic covering is twisted inward in the radial direction by sandwiching the elastic covering body over a predetermined length in the vertical direction at the position where the gap of the resin sheet is formed, and elastic covering The outer peripheral surface of the body and the resin sheet is separated from the cast concrete, and then the clip metal is pulled upward, and the elastic covering, the resin sheet, and the cap are pulled out from the boxed hole of the cast concrete. .
According to this feature, the elastic covering body, the resin sheet, and the cap can be easily and reliably pulled out from the box extraction hole using the clamp metal.

The present invention has the following excellent effects.
(1) Since a resin sheet having irregularities is interposed between the elastic covering covering the outer periphery of the box body for boxing and the placing concrete, the boxing hole of the placing concrete is made by this resin sheet. An uneven surface can be formed on the inner surface of the steel, and by using this uneven surface, anchor concrete can be firmly embedded in the cast concrete by integrating the separate concrete to be cast into the box punching hole with the cast concrete. . In that case, like the prior art 2, in the operation | work which winds a linear press body helically, and the extraction of the boxing formwork main body, a linear pressing body is made above a boxing formwork main body. The work of raising and reducing the diameter is unnecessary, and the work can be greatly improved.
Further, since the elastic covering body has appropriate elasticity, it is possible to easily pull out the box-drawing formwork main body and to easily pull out the elastic covering body and the resin sheet.
(2) Since the box-forming form body has a circular cross section having a taper whose diameter gradually decreases from the upper side to the lower side, the box-drawing form body can be more easily pulled upward. Can do.
(3) Since the box-forming form body has a structure that can be extended in the vertical direction, the vertical length of the box-forming form frame can be set according to the depth of the recess formed in the cast concrete. It can be adjusted as appropriate.
(4) The resin sheet having irregularities is coated on the outer peripheral portion of the elastic covering body so that gaps are formed at both ends in the circumferential direction, so that the outer peripheral surface shape of the elastic covering body is tapered. Even if it exists, it is not necessary to match the both ends of the circumferential direction of a resin sheet, and since there is no overlapping of the resin sheet which has an unevenness | corrugation, it can coat | cover on the outer peripheral surface of an elastic covering body in the closely_contact | adhered state.
Further, when the elastic covering and the resin sheet are removed from the box punching hole, the pinch metal fitting is attached to the gap of the resin sheet and twisted inward in the radial direction, and the outer peripheral surface of the elastic covering and the resin sheet is casted into the concrete. Conveniently spaced from.
(5) The resin sheet having projections and depressions is set at a position where the upper end is lower than the top end of the cast concrete, and the lower end is in contact with the upper end of the cap fitted to the box body and the bottom of the elastic covering. By setting in this way, it can form in a shape without an unevenness | corrugation in the top end of the casting concrete of a box punching hole. In addition, it is possible to prevent the cast concrete from entering from below between the box forming form main body and the elastic covering and between the elastic covering and the resin sheet.
(6) In order to draw out the box body for removing the box while leaving the elastic covering and the resin sheet, as in the prior art 2, the work for winding the linear pressing body in a spiral shape, and the box body for removing the box Therefore, the work of pulling up and reducing the diameter of the linear pressing body above the box main body for box extraction becomes unnecessary, and the work can be greatly improved.
Further, since the elastic covering body has appropriate elasticity, it is possible to easily pull out the box-drawing formwork main body and to easily pull out the elastic covering body and the resin sheet.
(7) After the box body for boxing is pulled out, the outer periphery of the elastic covering and the resin sheet are separated from the cast concrete by the clamps, and the elastic cover and the resin sheet are placed from the boxed hole of the cast concrete. And by pulling out the cap, the elastic cover, the resin sheet, and the cap can be pulled out easily and reliably from the box punching hole using the clamp metal fittings.

The pier after concrete placement, such as a highway with an anchor bolt embedded, is shown, (a) is a plan view, and (b) is a front view. It is AA sectional drawing of FIG. It is front sectional drawing which shows the state in which the boxing formwork was supported by the concrete formwork, and was installed. It is a top view which shows the lower suspension metal fitting with which the boxwork formwork was fixed. It is BB sectional drawing of FIG. It is a partial cross section figure which shows the form for box extraction. It is a partial cross section figure which shows the box extraction formwork in a modification. It is explanatory drawing for demonstrating the operation | work which extracts the formwork for box extraction from placement concrete. It is explanatory drawing for demonstrating the operation | work which extracts the resin sheet, cushion material, and cap which comprise a box extraction formwork from placement concrete.

  EMBODIMENT OF THE INVENTION The form for implementing the box cutting form and the die cutting method which concern on this invention is demonstrated below based on an Example.

FIG. 1 shows the pier 1 after placing concrete such as a highway. For convenience of explanation, the arrangement relationship of members will be described below using an XYZ orthogonal coordinate system. As for the planar position relationship, the horizontal direction is the X direction as shown in FIG. The vertical direction is defined as the Y direction. In the case of this example, four anchor bolts 3 are embedded in the upper surface 2 of the pier 1 in two locations in the X direction. Before the concrete is placed, a concrete formwork is installed along the outer shape of the pier 1, and reinforcing bars are arranged in the vertical, horizontal, and height directions on the inside. A box-extruding formwork is installed to form a vertical hole for anchor bolt embedding.
In addition, in this specification, the said vertical hole formed using the formwork for box extraction is called a box extraction hole.

  Incidentally, the upper surface 2 of the pier 1 may be formed to be horizontal or inclined in one direction as shown in FIGS. In any case, as shown in FIG. 2, the anchor bolt 3 is installed with reference to the horizontal plane 4, so that the box-forming form forming the box-cutting hole 5 as a recess is also based on the horizontal plane 4. Must be installed. For this reason, a horizontal surface 4 is formed on the installation surface of the anchor bolt 3 separately from the upper surface 2 of the pier 1, and a step 6 is formed between the upper surface 2 of the pier 1. There is. Since the positional relationship of the box hole 5 for burying the anchor bolt 3 is displayed on the concrete form installed along the outer shape of the pier 1, a box form for forming the box hole 5 is displayed. Is placed on the basis of this positional relationship displayed on the concrete formwork.

  In the present embodiment, a description will be given of an apparatus for supporting four box forming molds so as to embed four anchor bolts as a box forming form supporting apparatus. Needless to say, the number of frames can be set as appropriate. In FIG. 3, the concrete molds 14 and 14 on both sides are molds disposed on both sides with a space in the Y direction in FIG. In this example, the boxing form support device is arranged in the Y direction so as to be fixed to the concrete formwork 14 on both sides, and four boxing holes 5 for embedding anchor bolts are provided. Four boxing molds are supported so that they can be formed simultaneously. In this case, as a reference in the height direction, the box cutting form is positioned with reference to the anchor bolt position formed at the lowest position.

  The box-forming form support device has a lower suspension bracket 30 disposed below the upper suspension bracket 15 supported by the concrete molds 14 and 14 on both sides, and is disposed at an anchor bolt burying position in plan view. The suspended support rod 35 is vertically disposed so as to penetrate the upper suspension fitting 15 and the lower suspension fitting 30, and the suspension rod 35 is supported by the upper suspension fitting 15 so as to be adjustable in the vertical direction. The mold frame 50 is disposed so as to surround the suspension rod 35 and downward from the lower surface of the lower hanging bracket 30, and the box-extracting mold frame 50 is fixed by the suspension rod 35 to be held at the anchor bolt embedded position. Yes.

  Although not particularly illustrated, the upper hanging bracket 15 is composed of a pair of beam-like members arranged in parallel in the X direction with a gap therebetween. They are arranged in parallel with a gap slightly larger than the diameter and are integrally formed by means such as welding at both ends. The scale which displays a dimension is attached | subjected to the longitudinal direction of the beam-shaped member surface. Moreover, suspension wire attachment brackets 18 and 18 are provided on the upper surfaces of both sides in the longitudinal direction of the upper suspension bracket 15 and can be lifted and moved by a lifting device such as a crane.

  As shown in FIG. 3, on both sides in the longitudinal direction of the upper hanging bracket 15, fixing brackets for fixing to the concrete molds 14, 14 on both sides, that is, a clamping bracket 19 for clamping the concrete mold 14, a clamping bracket A screw rod 20 which is erected from 19 and is disposed through the upper hanging bracket 15 and nuts 21 and 21 with washers which are screwed into the screw rod 20 from above and below the upper hanging bracket 15 and attached thereto are mounted. . For this reason, the upper suspension fitting 15 is fixed to the concrete formwork 14 so as to be adjustable in the vertical direction.

  Although not particularly illustrated, a pair of X-direction positioning rulers is disposed at a position where the suspension rod 35 is disposed orthogonally to the pair of beam members of the upper suspension bracket 15, and the upper suspension bracket 15 By arranging a pair of Y-direction positioning rulers along the inside of the pair of beam-like members, among the four anchor bolt embedding positions, one reference anchor bolt embedding position is changed to the other three positions. It is possible to accurately determine the anchor bolt burying position.

  As shown in FIG. 4, the lower hanging hardware 30 is formed of corner hardware 31 arranged at four corners so as to form a rectangle and a connecting member 32 that connects these corner hardware 31, and each corner hardware 31. Has a cross shape in which cross-section box-shaped steel is crossed at right angles and joined, and a through-hole 33 for penetrating the suspension rod 35 is formed at the intersection, and adjacent corner hardware 31, 31 is formed. By fitting the connecting member 32 in a telescopic manner, the position of the corner hardware 31 can be adjusted. In this example, the cross-shaped corner metal 31 has a long fitting part 31a for fitting the connecting member 32 with the through hole 33 as a base point, and a short outer part 31b directed outward in the opposite direction. A fixing bolt 34 is provided in the fitting portion 31 a into which the member 32 is fitted.

  A step mold 36 is arranged around the lower hanging bracket 30 at a predetermined interval, and the step mold 36 is supported by a corner metal 31 of the lower hanging bracket 30. A crosspiece 37 is fixed to the inside of each side of the step mold 36 to facilitate reinforcement of the step mold 36 and support by the corner hardware 31 of the lower hanging bracket 30.

  As shown in FIGS. 4 and 5, the step mold 36 is fixed to the upper surface of the corner hardware 31 with the step mold fixing rod 40 provided so as to extend inwardly substantially horizontally with respect to the crosspiece 37. By being inserted into the box-shaped hardware 31 c in a nested manner, it is supported with respect to the lower hanging bracket 30. Note that two step-form fixing rods 40 are provided at two positions so as to be orthogonal to the crosspiece 37 for each of the four sides of the step-form frame 36.

  The crosspiece 37 of the step mold 36 has a rectangular cross section, and is fixed by a nail (not shown) from the step mold 36 side. The crosspiece 37 is fitted with a U-shaped metal piece 40a provided at one end of a step form fixing rod 40 inserted into the box-type metal piece 31c, and is supported by a support bolt 40b.

  The suspension rod 35 is disposed at a position where the anchor bolt is buried in plan view, and penetrates the upper suspension bracket 15 and the lower suspension bracket 30 as particularly shown in FIG. Thus, the box-extracting formwork 50 arranged in the vertical direction and arranged downward from the lower surface of the lower hanging metal fitting 30 is suspended and fixed. The suspension rod 35 is supported by the upper suspension bracket 15 so as to be adjustable in the vertical direction. For this reason, the suspension rod 35 is made of steel and has a circular cross section, and has a male thread cut on the surface thereof. The suspension rod 35 is tightened with a nut 49 with a washer from the upper surface side and the lower surface side of the upper suspension metal fitting 15, Suspended and supported at a height position.

  As shown in FIG. 6, the boxing form 50 has a circular cross section with a taper that gradually decreases in diameter from the upper side to the lower side, and a bottomed steel pipe 51 and, if necessary, the upper end of the steel pipe 51. The box forming form main body 53 of the box forming form 50 is configured by the extending member 52 having an outer surface of the same diameter as the upper end of the steel pipe 51. The steel pipe 51 and the extension member 52 are freely rotatable to a male screw portion 51b of a boss 51a supported by a support blade 51d inside the upper end of the steel pipe 51 and a sleeve 52e fixed to the center of the support blade 52c of the extension member 52. Are coupled to each other by screwing a female screw portion 52b of a boss 52a disposed at a lower end portion of the handle 52d supported by the screw. A substantially circular lid member 54 is disposed at the upper end of the extension member 52, and the male screw at the lower end of the suspension rod 35 is inserted into the insertion hole 54 b of the lid member 54 and the handle 52 d of the extension member 52. Furthermore, it couple | bonds by screwing with the internal thread part 51c formed in the boss | hub 51a of the steel pipe 51. FIG.

  A cushioning material 55 made of a resin foam material such as sponge is coated over substantially the entire outer periphery of the boxing mold main body 53, and the cushioning material 55 is elastically deformable in an arbitrary direction. Is covered with a resin sheet 56 having irregularities. The resin sheet 56 is a resin sheet-like member having irregularities formed at a predetermined density by embossing or the like, and has such rigidity that the irregularity shape is maintained against the pressure of the cast concrete. is doing.

  In order to cover the resin sheet 56 having irregularities on the outer periphery of the cushion material 55, as shown in FIG. 5, gaps are formed at both ends 57, 57 in the circumferential direction on the outer periphery of the tapered cushion material 55. In this manner, the resin sheet 56 is wound, and one surface of the double-sided adhesive tape 58 is adhered to the back surfaces of the both end portions 57 and 57, and the opposite surface is adhered to the surface of the cushion material 55. The resin sheet 56 is bonded so that gaps are formed at both ends 57, 57 in the circumferential direction. Since the outer peripheral surface of the cushion material 55 is tapered, it is troublesome to match both ends 57, 57. When the resin sheets 56 having unevenness are overlapped, the overlapping surfaces do not adhere to each other, so that the joining is difficult, and the resin sheet 56 and the cushion material 55 are separated from the box punching hole 5 as described later. It is because it is convenient.

Moreover, the upper end of the resin sheet 56 is set to be about 50 mm below the top end of the concrete to be placed. This is to prevent the uneven shape of the resin sheet 56 from being formed on the top edge of the concrete around the box extraction hole 5. The waterproof tape 59 is wound around the upper end outer peripheral surface of the resin sheet 56 and the outer peripheral surface of the cushion material 55 in order to prevent inflow of the cast concrete.
On the other hand, a cap 60 is attached to the bottom of the boxing formwork body 53 and the cushion material 55 so that the concrete does not flow between the boxing formwork body 53 and the cushioning material 55. Therefore, the lower end of the resin sheet 56 is set so as to contact the upper end of the cap 60. Further, a waterproof tape 61 is wound over the lower end of the resin sheet 56 and the outer peripheral surface of the cap 60 to prevent the inflow of concrete.

  It should be noted that the box forming mold 50 according to the present invention has a split structure that is detachable in the vertical direction so that the length can be adjusted according to the depth of the box punching hole in which the anchor bolt is embedded. For example, it may be configured by the steel pipe 51 and the extension member 52 as in the present embodiment, or may be configured by only the steel pipe 51 alone, or is shown in FIG. 7 as a modification of the present invention. As described above, two or more substantially the same extending members 52 and 52 ′ may be sequentially stacked on the upper end of the steel pipe 51. In this modification, the two extension members 52 and 52 ′ are formed by connecting a boss 52a at the lower end of the handle 52d of the upper extension member 52 and a boss 52a ′ fixed to the upper end of the handle 52d ′ of the lower extension member 52 ′. Further, the pin 66 fixed to the handle 52d 'of the lower extension member 52' is engaged with the support blade 51d of the steel pipe 51, and thereby the extension members 52, 52 'and the steel pipe are connected. This prevents the screw from coming off due to relative rotation with 51.

  Further, the lid member 54 has two steps of inner and outer stepped portions 54a on the periphery of the lower surface. When the lid member 54 is disposed on the extension member 52 as in this embodiment, the outer side of the stepped portion 54a. Is placed on the upper end surface of the extension member 52, and the step inside the step portion 54 a is the upper end surface of the steel pipe 51 when the lid member 54 is disposed on the steel pipe 51 thicker than the extension member 52. Placed on.

  As shown in FIG. 6, the lower end of the suspension rod 35 is screwed into the female thread portion 51 c of the steel pipe 51 that constitutes the boxing formwork body 53, and as shown in FIG. By tightening a wing nut 47 screwed to the suspension rod 35 on the upper surface side, the upper surface of the boxing mold 50 and the lower surface of the lower hanging bracket 30 are brought into close contact with each other. Retained. Since the boxing mold 50 is held by such a holding mechanism, even when concrete is cast, the boxing mold 50 can be prevented from being tilted, laterally moved, or vertically moved. .

  In order to install the box extraction formwork support device configured as described above, the upper suspension bracket 15 and the lower suspension bracket 30 are mounted so that the position of the suspension rod 35 in the XY direction is positioned as designed. Temporarily assembled on the ground, the temporarily assembled box-extracting formwork support device is lifted by a lifting device and mounted on a predetermined position of the concrete formwork 14. After that, by adjusting the vertical support position of the suspension rod 35 with respect to the upper suspension bracket 15, the boxing formwork 50 is disposed horizontally and at a predetermined height position via the lower suspension bracket 30, and concrete Ready concrete is placed in the formwork 14. The cast concrete that has been cast solidifies over time. Hereinafter, at least the concrete at the time of starting to solidify will be described as cast concrete C. The facing surface of the placing concrete C facing the boxing mold 50 is formed into a concavo-convex surface in which the concavo-convex is distributed at a constant density by the resin sheet 56 having the concavo-convex structure.

  FIG. 8 illustrates the extraction of the box forming mold 50 after the cast concrete C is formed. First, four jacks 62, 62 are disposed between the cast concrete C and the upper suspension bracket 15, and the clamping bracket 19 is loosened and the support bolt 40b is loosened so that the step form fixing rod 40 is inward. Pull in.

  Next, when the upper suspension bracket 15 is lifted upward by the jack 62, a force that moves upward is applied to the box extraction form body 53 via the suspension support rod 35. At this time, although the upward moving force acts on the cushion material 55 and the concave and convex shape of the resin sheet 56, the resin sheet 56 cannot escape from the boxing hole of the cast concrete C. Further, since the cushion material 55 is also bonded to the resin sheet 56 with an adhesive tape, the cushion material 55 cannot move upward. For this reason, the taper-shaped box body 53 is separated from the cushion material 55, and only the box body 53 is pulled upward.

After the box formwork main body 53 is pulled up, the cushion material 55, the resin sheet 56, and the cap 60 are left.
FIG. 9 is an explanatory diagram for explaining how the cushion material 55, the resin sheet 56, and the cap 60 are extracted from the cast concrete C. FIG.
As shown in FIG. 9A, a clamp metal fitting having a clamp portion 65 capable of sandwiching the cushion material 55 from the upper side to the lower side in a gap portion between both ends 57, 57 in the circumferential direction of the resin sheet 56. 63 (see FIG. 9B) is inserted downward from above to sandwich the cushion material 55. Next, as shown in FIG. 9C, when the shaft portion 64 is twisted about 180 ° inward with the pinching portion 65 of the pinching metal fitting 63 as a fulcrum, the cushion material 55 and the resin sheet 56 are drawn inward in the radial direction. It is. In the process of becoming this state, the diameters of the cushion material 55 and the resin sheet 56 are reduced and peeled off from the cast concrete C. Therefore, if the clip metal 63 is pulled upward, the cushion material 55, the resin sheet 56, and the cap 60. Can be extracted from the cast concrete C.

  Since the outer peripheral surface of the cushion material 55 is covered with the resin sheet 56, fresh concrete containing moisture before solidification does not enter the cushion material 55.

  As described above, when the upper hanging bracket 15 is lifted upward by the jack 62, only the box formwork main body 53 moves upward via the suspension rod 35 and comes out of the cast concrete C. At this time, the cushion material 55, the resin sheet 56, and the cap 60 remain in the cast concrete C, but these are easily extracted from the cast concrete C using the clip metal 63, and the inner surface of the cast concrete C has an uneven shape. The uneven surface due to the resin sheet 56 can be left.

  The extracted cushion material 55, the resin sheet 56, and the cap 60 are not damaged, and the elastically deformed cushion material 55 is elastically restored. Therefore, the cushion material 55 can be reused again and again by being attached to the box body 53. Is possible.

  As described above, according to the boxing formwork 50 of the present invention, the boxing formwork body 53 has a tapered shape and can be easily removed, and the boxing formwork body 53 is covered. Since the cushion material 55 as the elastic covering body can also be deformed in the direction of diameter reduction, the cushion material 55, the resin sheet 56, and the cap 60 can be easily removed.

  In addition, an uneven surface can be formed on the inner surface of the box extraction hole 5 of the cast concrete C by the resin sheet 56 having the unevenness provided on the outer peripheral portion of the cushion material 55, and the box extraction hole can be formed using the uneven surface. The anchor bolt can be firmly embedded in the cast concrete C by integrating the separate concrete to be cast in 5 with the cast concrete C.

  Even when the cushioning material 55, the resin sheet 56 and the cap 60 are pulled out, the cushioning material 55 is elastically deformed, so that the cushioning material 55 is easily pulled out. In order to restore elasticity later, it is easy to attach these members to the boxing formwork body 53, and the boxing formwork 50 can be used repeatedly.

  Moreover, since the cushion material 55 is waterproofed by the resin sheet 56 and the cap 60, the said function can be exhibited reliably, without the fresh concrete containing a water | moisture content permeating the cushion material 55 and deteriorating the cushion material 55. FIG. In addition, an uneven surface can be formed on the inner surface of the box extraction hole 5 of the cast concrete C by the uneven shape of the resin sheet 56.

  Further, the box forming mold main body 53 is configured to be vertically extendable, so that the box removing mold body 53 can be formed according to the depth of the box opening hole 5 as a recess formed in the cast concrete C. The vertical length of the main body 53 can be adjusted as appropriate.

  Although the embodiments of the present invention have been described with reference to the drawings, the specific configuration is not limited to these embodiments, and modifications and additions within the scope of the present invention are included in the present invention. It is.

  For example, in the above embodiment, the cushion material 55 as the elastic covering body of the present invention is made of a resin foam material and is configured to be elastically deformable in an arbitrary direction. For example, the elastic covering body is made of a low resilience resin. In this way, the elastic covering made of the low-resilience resin keeps the shape of the resin sheet 56 facing the concrete pressure for a relatively long time. Holes can be formed. Further, even when the diameter of the box extraction hole 5 is changed, it can be dealt with by changing the thickness of the cushion material 55 or the number of windings without changing the diameter of the box body 53 for box extraction.

  For example, in the said Example, although the resin sheet 56 and the cushioning material 55 or the resin sheet 56 and the cap 60 were joined by the adhesive tape, it should just be what can be fixed with waterproofness. .

DESCRIPTION OF SYMBOLS 1 Bridge pier 3 Anchor bolt 5 Box extraction hole 14 Concrete formwork 15 Upper suspension metal fitting 30 Lower suspension metal fitting 35 Suspension support rod 36 Formwork for level difference 50 Formwork for box removal 51 Steel pipe 52 Extension member 53 Box formwork main body 54 Lid Member 55 Cushion material (elastic covering)
56 Resin Sheet 57 Circumferential End 58 of the Resin Sheet Double-sided Adhesive Tape 59 Waterproof Tape 60 Cap 61 Waterproof Tape 62 Jack 63 Clamping Metal 64 Shaft 65 Clamping 66 Pin

Claims (7)

A box-forming form for forming a recess in the cast concrete to be cast in the concrete form surrounding the side,
A suspension rod supported by a suspension bracket supported by the concrete formwork, a boxing formwork body having rigidity fixed to the suspension rod, and an outer peripheral portion of the boxing formwork body. A box forming form comprising: an elastic covering provided so as to cover; and a resin sheet having irregularities covered on an outer periphery of the elastic covering.   2. The boxing formwork according to claim 1, wherein the boxing formwork main body has a circular cross section having a taper that gradually decreases in diameter from above to below.   The boxing formwork according to claim 1 or 2, wherein the boxing formwork body has a structure that can be extended in the vertical direction.   The resin sheet having the unevenness is coated on an outer peripheral portion of the elastic covering body so that a gap is formed at both ends in a circumferential direction. Boxing formwork.   The resin sheet having the unevenness is set at a position where the upper end is lower than the top end of the cast concrete, and the lower end is in contact with the upper end of the cap fitted to the bottom part of the boxing formwork body and the elastic covering. The box-extruding form according to any one of claims 1 to 4, which is set. A die-cutting method for a box-drawing mold for forming a recess in the cast concrete to be cast in a concrete mold surrounding the side,
Provided to cover the outer peripheral portion of the box body for box extraction, which is fixed to the suspension rod and has rigidity, so as to cover the elastic covering, and further, the outer peripheral portion of the elastic covering is covered with a resin sheet having irregularities,
The suspension rod for fixing the box-extracting formwork body mounted with the elastic covering and the resin sheet is suspended in a suspension fitting supported by the concrete formwork and disposed in the concrete formwork. ,
After the concrete placed in the concrete mold is solidified, the box-drawing mold main body is lifted upward via the suspension support rod, and the elastic cover and the resin sheet are left to be pulled out. Die-cutting method for box-cutting formwork. After the box body for box extraction is pulled out, the elastic covering is twisted inward in the radial direction by sandwiching the elastic covering body over a predetermined length in the vertical direction at the position where the gap of the resin sheet is formed, and elastic covering After the outer peripheral surface of the body and the resin sheet is separated from the cast concrete, the clip metal is pulled upward, and the elastic covering, the resin sheet, and the cap are pulled out from the box opening hole of the cast concrete. The die cutting method of the boxing formwork of Claim 6.

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