JP3455197B2 - Structure of insert nut mounting part of concrete formwork - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an insert nut mounting portion of a concrete formwork. 2. Description of the Related Art Insert nuts are embedded in concrete products for various purposes such as lifting concrete products and connecting concrete products. Such an insert nut is embedded by pouring concrete into a mold and hardening the insert nut in a state where the insert nut is mounted on the inner surface of the mold in advance. FIGS. 3 and 4 are explanatory views showing the structure of a nut embedding part of a conventional concrete formwork. Form holes 32 are formed in the form 30 at positions where the insert nuts 31 are to be embedded. As shown in FIG. 3, bolts 33 are passed through the form holes 32 from outside and the insert nuts 31 are screwed from inside. And fix it. After the concrete is poured and hardened, the bolt 33 is removed with an impact wrench or the like, and the mold is removed as shown in FIG. [0004] The structure of the insert nut embedding portion of the conventional concrete form has the following drawbacks. The work of screwing the bolt in fixing the insert nut and the work of removing the bolt with an impact wrench or the like in removing the mold are complicated and the work efficiency is poor. When the formwork is large, fixing the insert nut requires two workers, a person screwing a bolt outside the formwork and a person holding down the insertnut inside the formwork. When fixing the insert nut with bolts from the lower side of the formwork, it is dangerous because an operator has to dig into the lower side of the formwork. The present invention solves such a problem,
An object of the present invention is to provide a structure of an insert nut embedding portion of a concrete product which is simple and less dangerous. SUMMARY OF THE INVENTION The present invention provides a thin-walled cylinder which is made of an elastic material such as rubber or soft resin and has an opening at the front end and a bolt hole formed in a closing wall at the rear end. A bolt having a shape formed therein is inserted into the bolt from the tip end side through the bolt hole and the hole of the formwork, and a nut is screwed to the bolt from the outside of the formwork to thereby fix the bolt head. By pressing and holding the closed end wall, the structure of the insert nut mounting portion of the concrete formwork mounted on the formwork in a state of protruding to the formwork inner surface, by a toggle clamp attached to the formwork outer surface, A structure of an insert nut attaching portion of a concrete formwork, wherein the fitting is attached so as to be retractable to the outside of the formwork. According to the present invention, in the above construction, a thin-walled cylindrical fitting with an open end made of an elastic body is mounted so as to protrude from the inner surface of a formwork, thereby providing an insert nut for a concrete production line. Attachment to the mold can be easily performed by pushing the hole of the insert nut into a fitting projecting from the inner surface of the mold so as to fit it. The mounting fixture is made of an elastic body such as soft resin or rubber, and has a thin cylindrical shape with an open end, so it is rich in elasticity and can easily insert nuts, not only does not damage the screw threads, The insert nut does not easily come off even when the concrete is poured or compacted. Also, there is no concrete leakage into the insert nut. [0007] The fixture is attached to the outside of the mold so as to be retractable, and when the mold is removed, the fixture can be retracted so that any removal method can be applied. For example, the present invention can also be used in a case where a concrete product is moved in a direction substantially parallel to the formwork surface and then removed. 1 and 2, a fitting 1 made of nylon resin is formed in a thin cylindrical shape. The average thickness of the peripheral wall portion is about 1 mm, and the thickness of the closing wall portion at the rear end is about 2.5 mm. The average thickness of the peripheral wall portion varies depending on the size of the insert nut to be attached, but is preferably 3 to 10% of the inner diameter of the insert nut from the viewpoint of utilizing the elasticity of the fixture. If the thickness is too small, it is weak to the impact at the time of putting concrete, and if it is too thick, it becomes difficult to insert and remove the insert nut. The outer periphery of the peripheral wall is slightly tapered near the tip, and the tip is slightly thinner than the inner diameter of the insert nut 3 (internal thread method), and the diameter of the outer wall is a part where the diameter is larger. Is slightly thicker than the inner diameter of the insert nut 3 so that the threads of the insert nut can bite into the insert nut 3 so that it can be firmly fitted. A hole 2 for bolt attachment is provided in a closed wall at the rear end of the fixture 1. The fixture 1 includes a bracket 27, a sliding shaft 21,
It is attached to the formwork 28 by a toggle clamp 23 or the like. The bracket 27 is a so-called angle material,
8 Welded and fixed to the outer surface. The toggle clamp 23 is provided on the bracket 27. Toggle clamp 2
Reference numeral 3 includes a U-shaped member 24, a lever 25, and a support piece 26. One end of the V-shaped member 24 is pin-joined to the rear end of the slide shaft 21 and the other end is pin-joined to one fulcrum of a lever 25.
The other fulcrum 5 is pin-joined to the support piece 26. The sliding shaft 21 slides inside the cylindrical bearing 22 to slide in parallel with the upper surface of the bracket 27. The attachment 1 is attached to the tip of the sliding shaft 21 with bolts 20 via several washers. [0010] As shown in FIG. 1, with the fixture 1 protruding inward from the hole 29 of the mold frame 28,
Push in and fit. Concrete is put into a mold, and the mold is released after curing. When removing the mold, lever 25
Is tilted in the direction of arrow B as shown in FIG.
The slide shaft 21 is moved outward, and the fixture 1 is pulled out of the insert nut 3. The embodiments of the present invention can be adapted to any demolding method. For example, a demolding method in which the concrete product is pushed upward without opening the mold is also possible because the fixture is completely pulled out of the mold. The present invention relates to a method for mounting an insert nut in a concrete product manufacturing line.
Since the insert nut may be fitted to a fitting projecting from the inner surface of the mold, it is very simple. Of course, a tool such as an impact wrench is not required, and even a large formwork requires only one worker, and there is no need to take the danger of working under the formwork. Further, the present invention can be applied to not only the case where the mold is removed by removing the mold straight at right angles to the concrete surface but also the case where the mold is opened and removed, and the case where the mold is removed in a direction parallel to the concrete surface.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic sectional view showing a structure of an insert nut mounting portion of a concrete formwork according to one embodiment of the present invention. FIG. 2 is a view similar to FIG. 1 showing a detached state. FIG. 3 is a cross-sectional view of an insert nut mounting portion of a conventional concrete formwork. FIG. 4 is an explanatory diagram of a detached state of FIG. 3; [Description of Signs] 1 Fixture 3 Insert nut 20 Bolt 21 Sliding shaft 22 Bearing 23 Toggle clamp 24 Rectangular member 25 Lever 26 Supporting piece 27 Bracket 28 Formwork 29 Hole

Claims (1)

(57) [Claims 1] A thin cylindrical shape to which an insert nut is fitted, which is made of an elastic body such as rubber or soft resin and has an opening at a front end and a bolt hole at a closing wall at a rear end. A bolt is inserted into the formed fixture from the front end side and inserted into the bolt hole and the hole of the mold, and a nut is screwed to the bolt from the outside of the mold, and the bolt head is fixed at the bolt head. By pressing and holding the closed end wall, the structure of the insert nut mounting portion of the concrete formwork mounted on the formwork in a state of protruding from the formwork inner surface, wherein the mounting is performed by a toggle clamp mounted on the formwork outer surface. Structure of insert nut for concrete formwork, characterized in that fittings are attached to the outside of the formwork so as to be retractable