JP2009138473A - Insert fitting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insert fitting of simple constitution allowing a holder to be easily reused. <P>SOLUTION: The insert fitting is screwed to a bolt fastening insert 1 embedded in a concrete structure 8, and inserted through a form 3 to fit the insert 1 to the form 3 before placing concrete. The insert fitting comprises a mounting bolt 2 screwed to the insert 1; a cylindrical holding body 5 composed of material incompatible with concrete and covering the periphery of the mounting bolt 2; and a nut for fixing the mounting bolt 2 to the form 3. The form 3 side end of the mounting bolt 2 is provided with an external thread part 2b screwed to the nut 4, and an engaging part 2a engaged with a removing tool. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an insert fixture for attaching an insert for bolting into a concrete structure before the concrete is placed.

  When fixing bolts and suspension bolts to a concrete structure, for example, a concrete wall or ceiling, inserts are embedded in predetermined positions of the concrete structure, and these bolts are screwed and fixed. This insert is attached in advance to the inside of the mold before placing concrete, and is used in a state of being embedded in concrete after placing concrete. As the insert, a ceramic insert is conventionally used, and a screw portion is opened in the insert, and the bolt is screwed into the screw portion.

  This conventional procedure for embedding inserts will be described. First, one of the two workers comes to the side where the concrete of the mold is to be placed, holds the insert, and fits the tip of the insert to the position of the insert support hole that has been previously opened in the mold. On the other hand, another worker outside the mold inserts the bolt of the insert fixture into the insert support hole, engages with the thread portion of the insert, and fixes the insert to the mold. Concrete is cast in a state where the insert is cantilevered inside the formwork, and after the concrete is hardened, the bolts are removed and the formwork is removed. Thereafter, the above-described bolts or suspension bolts are screwed into the insert embedded in the concrete.

  By the way, when concrete is poured into the above-mentioned formwork, when concrete is poured directly into the insert fixture and insert inserted into the insert support hole and fixed to the formwork, the bolt is fixed in the concrete. It is difficult to remove bolts after they are buried and the concrete has hardened. Therefore, a cylindrical holder is usually attached to the bolt. The holder is often made of ceramic, and when the tip of the bolt is screwed with the insert, it is sandwiched between the mold and the insert and fixed. When the concrete is hardened, only the bolts are removed, and the retainer is left in the concrete together with the insert and is used while being embedded in the concrete. However, with this method, the holder cannot be reused and reused.

  Therefore, as shown in FIG. 8, it is embedded between the insert 101 and the outer surface of the concrete structure 102, and one end is screwed with the female thread portion of the insert 101, and an engaging portion with the removal tool is provided on the other end side. The formed holding tool 103 has a threaded portion that engages with the other end of the retainer 103 at one end, an engaging portion that engages with the mold 106 at the other end, and is engaged with the threaded portion. There has been proposed an insert device including a joint 105 having a break portion 104 for breaking both of them between the joint portions and having an engagement portion with a removal tool inside (see Patent Document 1). The holder 103 and the joint 105 are made of a resin such as polypropylene. FIG. 8 is a configuration diagram of a conventional insert fixture.

  When the mold 106 is pulled after the placement, the fracture portion 104 of the joint 105 is broken and the mold 106 can be peeled off. In addition, since the breakage is performed at the joint 105, the holder 103 can be reused without changing from the state before use if the remaining portion of the joint is removed.

JP 2002-194819 A

  As described above, when a conventional insert is used, the retainer is indispensable because the bolt after concrete hardening cannot be pulled out without the retainer. However, it is difficult to reuse conventional holders. This is because the ceramic holder is firmly fixed to the concrete and cannot be removed from the concrete structure after the concrete has hardened. Therefore, it is unavoidable that the holder is still embedded in the concrete together with the insert.

  In this regard, the insert device disclosed in Patent Document 1 can reuse the holder, but this insert device breaks both between the screwing portion and the engaging portion separately from the holder. It is necessary to use a joint with a break for the purpose. If the holder can be reused, the joint is discarded instead. In this case, only half was reusable, but it could not be said that it could be reused in the full sense.

  In this way, if the holder is left embedded in the concrete together with the insert, the cost becomes high, and even if the joint is discarded and only the holder is recovered as in Patent Document 1, the cost becomes high. Moreover, the structure of the holder of patent document 1 is complicated. It is desirable to have an insert device that can be reused with a simple structure if possible and without troublesome work.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an insert fitting that can be easily reused with a simple configuration.

  The present invention is an insert fitting that is screwed into a bolt fastening insert embedded in a concrete structure, is inserted into a mold and attaches the insert to the mold before placing the concrete, and the insert fitting is inserted into the insert. A mounting member to be screwed, a cylindrical holder that covers the periphery of the mounting member and is made of a material that is not compatible with concrete, and a nut for fixing the mounting member to the formwork. A main feature is that an end portion on the frame side is provided with a screwing portion to be screwed with the nut and an engaging portion to be engaged with the removal tool.

  According to the insert fixture of the present invention, the holder can be easily reused with a simple configuration, and the cost required for installation of the insert can be greatly reduced.

  The first form of the best mode for carrying out the present invention is an insert fitting that is screwed into a bolt fastening insert embedded in a concrete structure and is inserted into the mold and attached to the mold before placing the concrete. The insert mounting tool is a mounting member that is screwed into the insert, a cylindrical holding body that covers the periphery of the mounting member and is made of a material that is incompatible with concrete, and the mounting member is fixed to the formwork. And a fitting portion engaging with the removal tool is provided at an end of the attachment member on the mold side. It is an insert fixture.

  With this configuration, the holding body is not fixed to the concrete. By removing the nut and removing the formwork, the holding body can be easily taken out and reused, which is necessary for the installation of the insert. Cost can be greatly reduced.

  The second form of the present invention is an insert attachment characterized by being dependent on the first form, wherein the holding body is made of silicon, has no affinity with concrete, and has strength. Can be reused repeatedly.

  A third form of the present invention is a form subordinate to the first or second form, wherein the engaging part is formed by cutting the threads of the threaded part flat on two parallel surfaces. This is an insert mounting tool that can be arranged in one place with the screwed portion of the nut and the engaging portion for the tool such as a spanner, and the shape of the mounting hole of the packing is different from the shape of the bolt body or the holding body. As a result, as particularly noticeable in the case of the D cut, it functions as an insertion stopper for the packing, and can be easily fixed to the mold with only the nut and the packing. It is easy to grip the spanner engaging portion with a spanner or the like, and the gripping force is insufficient, so that it does not slip and cause rotation.

(Embodiment 1)
Hereinafter, the insert fixture in Embodiment 1 of this invention is demonstrated. FIG. 1 is a partially broken cross-sectional view when embedding an insert fixture in Embodiment 1 of the present invention, FIG. 2 is an exploded view of a mounting bolt of the insert fixture in Embodiment 1 of the present invention, and FIG. The perspective view of the holder and attachment bolt in Embodiment 1 of invention, FIG. 4 is explanatory drawing of each process when collect | recovering a holder and attachment bolt from the insert in Embodiment 1 of this invention.

  1 to 3, reference numeral 1 denotes an insert serving as an anchor portion for fixing a bolt to a concrete structure, for example, a concrete wall or a ceiling to fix an object to be attached or fixing a suspension bolt. In the first embodiment, the insert 1 is made of ceramic. The details of the metal (steel) insert 1 will be described in the second embodiment. Reference numeral 1a denotes a female screw for screwing formed in the insert 1, and 2 denotes a mounting bolt made of steel or stainless steel for screwing the female screw 1a of the insert 1 to attach an object to be attached to a mold 3 (to be described later). It is an attachment member in the present invention. The mounting bolt 2 is different from the bolt that is fixed after the concrete is hardened, and is a part of an insert mounting tool that is used when placing concrete.

  Here, since the insert 1 is used by being embedded in concrete for a long period of time, it is preferable that the insert 1 is made of ceramic in terms of durability and strength. However, it can be made of a material such as hard plastic, or can be made of metal as described above. When the mounting bolt 2 is used, a nut 4 or the like, which will be described later, is screwed to one end side, and the other end side is screwed to the insert 1 to hold the formwork. When releasing the screwing between the mounting bolt 2 and the insert 1, the nut 4 is first removed with a spanner, and the flat engaging portion with the thread that has been tightened with the nut 4 is rotated with a spanner or a wrench. To release.

  The details of the mounting bolt 2 will be described. In 2a, a part of the thread is cut flat on two parallel surfaces to be engaged with a spanner or a wrench, and the cut surface is scattered in a stepping stone shape due to the thread groove. The spanner hanging part 2b which comprises a flat surface (two planes parallel to the top and bottom) as a whole is a male screw part which is screwed with the nut 4 carved on the peripheral surface other than the spanner hanging part 2a. Reference numeral 2c denotes a male screw portion where the mounting bolt 2 is screwed with the insert 1, and 2d denotes a bolt body in which a male screw connected to the male screw portions 2b and 2c is formed. Since the mounting bolt 2 of the first embodiment forms the spanner hanging portion 2a only by cutting a part of the screw thread of the bolt having no head, the mounting bolt 2 can be manufactured easily and inexpensively.

  Reference numeral 3 denotes a formwork for placing concrete, and 3a denotes an attachment hole opened for attaching the attachment bolt 2 to the formwork 3. The mounting hole 3a has a contour composed of a straight linear portion parallel to the cross-sectional shape of the spanner hanging portion 2a and two arc portions formed with a male screw portion 2b connecting the same, and the spanner hanging portion 2a is inserted therethrough. It is opened with a size slightly larger than this. One end side of the mounting bolt 2 is inserted into the mounting hole 3a.

  1 to 3, reference numeral 4 denotes a nut such as a hexagon nut that is screwed onto the mounting bolt 2. 5 is provided to secure the cover of the insert 1 (to ensure the thickness of the concrete covering the surface). Cylindrical material that is not compatible with concrete (the concrete hardly adheres when cured) such as silicone rubber In the case of the first embodiment, the holding body can be taken out after concrete placement and reused repeatedly as described later.

Here, the silicone rubber constituting the holding body 5 will be described. Silicone rubber is a rubber whose structure has silicon and oxygen in the main chain, and is a millable (solid rubber) HTV (High Temperature).
Vulcanization), liquid or paste-like RTV (Room Temperature Vulcanization), and LTV (Low Temperature Vulcanization) exist. The holder 5 of the present invention is required to have (a) non-affinity with concrete, (b) moderate elasticity, (c) ease of production, (d) low cost, etc. Silicone rubber is a suitable material.

  This millable type silicone rubber hardly adheres to the concrete and becomes very easy to remove after the concrete has hardened. Further, since silicone rubber exists between the concrete and the mounting bolt 2 and has an appropriate elasticity, the mounting bolt 2 can be easily removed. Furthermore, even if the concrete hardens and shrinks, the silicone rubber acts as a cushion and absorbs it. And if the thickness of the rubber is about 0.5 mm or more than 0.5 mm, these objects can be sufficiently achieved. As the hardness of the silicone rubber to be used, a hardness of about 20 to 80 is appropriate according to the test method of JIS6253.

  In addition, since the holding body 5 is formed in a cylindrical shape, it can be extruded, and the holding body 5 can be obtained simply by cutting the molded product thus obtained to an appropriate length. 5 can be manufactured at low cost. Silicone rubber molding takes time in the past, so it was inevitably expensive to mold each product. In the present invention, however, by combining silicone rubber extrusion and cutting, both production time and production cost are reduced. Can be made inexpensive. Moreover, it can be used repeatedly, and the construction cost of the construction company using the insert fixture, and hence the cost of the building can be reduced.

  Moreover, the silicone rubber is excellent in cold resistance, heat resistance, and weather resistance, and can be used in a building of any environment, and the transparent holding body 5 and the opaque holding body 5 can be easily formed only by changing the additive. In the case of the transparent holding body 5, even if it remains in the concrete, it is lost to the surrounding concrete and does not break the harmony with it. The mounting bolt 2 inserted therethrough can also be directly observed during work. On the other hand, in the case of the opaque and colored holding body 5, it is possible to prevent the holding body 5 from being left in the concrete and to leave it, so that the work of disassembling the mold can be performed easily.

  Next, 6 is a packing made of durable hard rubber or plastic, and is inserted to the deepest position of the spanner hook 2a. 6a is a difference in shape to be fitted to the spanner hook 2a of the mounting bolt 2. It is a hole. The holding body 5 is inserted between the packing 6 and the insert 1 to secure the concrete cover. The packing 6 prevents the concrete from leaking from the mounting hole 3a when placing concrete. In the case of Embodiment 1, the packing 6 is also removed after placing the concrete and can be used repeatedly.

  In addition, as a material of this packing 6, plastics and rubbers, such as polyethylene (PE), polypropylene (PP), and a fluororesin, are suitable. The mounting bolt 2 described in the first embodiment has been described with a diameter of 12 mm in mind, but an insert mounting tool having a larger size can be easily made by the method described above.

  By the way, the feature of the insert fixture of the present invention is that the holding body 5 and the packing 6 can be reused. As in the prior art, the ceramic holding body 5 remains in the concrete together with the insert 1 because the value of the holding body 5 occupies almost half of the remaining value including the insert 2 and is used as an auxiliary when burying the insert. The cost is increased for the parts to be used. However, the holder 5 has not been collected in the past. This is because an extra cost more than the collection occurs in order to reuse the holding body 5, and the removal work becomes troublesome. Another reason is that the holder 5 of an appropriate material to replace ceramic is unknown. In order to enable reuse in the future, a material that has poor affinity between the holding body 5 and the concrete and does not adhere even when the concrete is cured is necessary.

  Therefore, in the present invention, as described above, the holding body 5 is made of silicone rubber, thereby reducing the affinity between the holding body 5 and the concrete and realizing the holding body 5 that does not adhere to concrete. The packing 6 also has a poor affinity with concrete, and a material such as PE, PP, fluororesin, or the like that does not adhere to the concrete and the mounting bolt 2 is used.

  Therefore, in the case of the first embodiment, when the concrete is hardened, the nut 4 can be removed, the mold 3 can be pulled out, and the packing 6 and the holding body 5 can be easily removed from the concrete. That is, when the nut 4 is removed and the mold 3 is pulled out, the mounting bolt 2 is in a state in which the spanner hook 2a protrudes from the concrete. Here, when the spanner is engaged with the exposed spanner hook 2a and rotated, the screwing of the mounting bolt 2 and the insert 1 can be released. Then, if the packing 6 and then the holding body 5 are pulled out from the concrete, only the insert 1 is embedded in the concrete.

  Then, based on FIGS. 1-4, the procedure of the operation | work which attaches the insert fixture of Embodiment 1 to the formwork 3, and also collect | recovers the holding body 5 grade | etc., Is demonstrated. First, the order of installation will be described. The packing 6 is inserted into the spanner hook 2a of the mounting bolt 2, the spanner hook 2a is inserted into the mounting hole 3a of the mold 3, and the nut is held between the mold 3 4 is screwed together. As a result, the male screw portion 2 c side (insert 1 side) of the mounting bolt 2 is in a state of protruding from the mold 3.

  Next, the holding body 5 as shown in FIG. 3 is inserted into the mounting bolt 2 and pushed into the mounting bolt 2 protruding from the mold 3. Further, it is screwed into the female screw portion 1 of the insert 1 with the male screw portion 2c at the tip. As a result, a state in which the insert fixture is held in the mold 3 as shown in FIG. 1 is obtained. The length of the cylinder of the holding body 5 is the thickness of the concrete cover with respect to the insert 1.

  In this state, the concrete is placed, and when it is cured, an operation of collecting the holding body 5 and the like is performed. The operator removes the nut 4 and rotates the spanner in the direction of loosening by engaging the spanner hook 2a. As a result, the mounting bolt 2 can be pulled out, resulting in a state as shown in FIG.

  4A, 4B, and 4C, in FIGS. 4A, 4B, and 4C, 8 is hardened concrete, 9 is the mounting bolt 2, packing 6, and It is a cylindrical filling material that fills the space from which the holding body 5 is removed in order.

  The filling 9 is packed into a cavity (space) formed by removing the packing 6 and the holding body 5. This material may be any material, such as mortar or plastic, and is cylindrical so as not to interfere with the insertion of bolts that are fixed after the concrete has hardened. Since it can be formed at a lower cost than in the past, in some cases, the transparent holding body 5 can be left in the concrete 8 to replace the filler 9.

  Further, the recovery procedure will be described with reference to the drawings. First, the packing 6 is removed from the state shown in FIG. As a result, the state shown in FIG. Next, since the holding body 5 and the concrete 8 are not fixed (attached), the holding body 5 is pulled out. As a result, a cavity in which the holding body 5 was present is formed between the insert 1 and the wall surface of the concrete 8. The filling 9 as shown in FIG. 4C is fitted into the cavity on the front surface of the insert 1, and the operation is completed. As a result, the recovered holder 5 and packing 6 can be reused. If filling is not necessary, it may be left as a cavity, and there is no need to insert the filling 9. Bolts, suspension bolts and the like are screwed into the inserts 1 embedded in the concrete 8 and used as anchor portions.

  Thus, in Embodiment 1, since the holding body 5 is made of silicone rubber, the affinity between the holding body 5 and the concrete is poor, and due to moderate elasticity, even when the concrete is cured, it does not adhere. Since the holding body 5 is formed in a cylindrical shape, it can be extruded and formed by simply cutting the obtained molded product into an appropriate length. Therefore, the manufacturing time can be reduced, and the holding body 5 can be compressed. Can be manufactured at low cost. Silicone rubber absorbs this shrinkage when the concrete shrinks upon curing.

  Further, the packing 6 does not adhere to the concrete and the mounting bolt 2 in terms of material. And by adopting a simple configuration in which the thread of the mounting bolt 2 is partly cut and the spanner hanging portion 2a is provided together with the configuration of the holding body 5 and the packing 6, the insert mounting tool is inexpensive and easy. Can be re-used and can be reused. When the concrete is hardened after placing, the holding body 5, the packing 6, and the mounting bolt 2 can be recovered and reused, and the cost required for installing the insert can be greatly reduced. As a result, the cost of the building can be reduced.

(Embodiment 2)
Hereinafter, the insert fixture in Embodiment 2 of this invention is demonstrated. FIG. 5 is a partially broken cross-sectional view when the insert fixture according to Embodiment 2 of the present invention is embedded, and FIG. 6 is an exploded view of the mounting bolt of the insert fixture according to Embodiment 2 of the present invention. The insert fitting in the second embodiment is different from the insert fitting in the first embodiment only in the material and structure of the insert, and the other parts are the same. 1 to 4 will be referred to also in FIG. 2, and the common reference numerals indicate the same configuration, so the detailed description will be given to the first embodiment.

  5 and 6, reference numeral 2e denotes a flat plate-like spanner engaging portion that is D-cut for engaging with a spanner or the like. The mounting hole 3a has a contour composed of a parallel linear portion and two arc portions in which the male screw portion 2b is engraved so as to match the cross-sectional shape of the spanner engaging portion 2e, and the spanner of the mounting bolt 2 The opening is slightly larger than this so that the engaging portion 2e can be inserted.

  5 and 6, the D-cut wrench engaging portion 2 e functions as an insertion stopper for the packing 6 because the shape of the mounting hole 3 a of the packing 6 is different from that of the bolt body 2 d and the holding body 5. It can be easily fixed to the formwork 3 using only the nut 4 by inserting 6 into the back. Since the spanner engaging portion 2e is thin, it is easy to grip the spanner engaging portion 2e with a spanner or the like, and the gripping force is insufficient so that it does not slide and cause rotation.

(Embodiment 3)
Hereinafter, the insert fixture in Embodiment 3 of this invention is demonstrated. FIG. 7 is a perspective view of an insert that is attached by an insert fixture according to Embodiment 3 of the present invention. The insert fitting in the third embodiment is the same as the insert fitting in the first embodiment except for the material and structure of the insert, and the other parts are the same. Since the common reference numerals indicate the same configuration, the detailed description will be given to the first embodiment.

  In FIG. 6, reference numeral 11 denotes a concrete structure, for example, a metal insert such as steel for fixing a to-be-attached object by fixing a bolt to a concrete wall or ceiling, or fixing a suspension bolt. Reference numeral 11a denotes a locking portion made of a substantially triangular thick plate that serves as an anchor portion of the insert 1, and 11b denotes a threaded cylinder formed with a female screw. If it becomes a rotation stop, it will not be restricted to a substantially triangular shape.

  Thus, since the insert 1 of the insert fixture according to the third embodiment is made of metal instead of ceramic, it is easy to manufacture, and the shape is a cylindrical threaded tube 11b formed with a locking portion 11a and a female screw. Can be manufactured at a lower cost than in the prior art.

  The present invention can be applied to an insert fixture for attaching an insert to a formwork.

Partially fractured sectional view when embedding the insert fixture in Embodiment 1 of the present invention Exploded view of a mounting bolt of an insert mounting tool in Embodiment 1 of the present invention The perspective view of the holder and attachment bolt in Embodiment 1 of this invention Explanatory drawing of each process when collect | recovering a holder and a mounting bolt from the insert in Embodiment 1 of this invention. Partially fractured cross-sectional view when embedding an insert fixture according to Embodiment 2 of the present invention Exploded view of a mounting bolt of an insert mounting tool in Embodiment 2 of the present invention The perspective view of the insert attached with the insert fixture in Embodiment 3 of this invention Configuration diagram of conventional insert fixture

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insert 1a Female screw 2 Mounting bolt 2a Spanner hook part 2b Male screw part 2c Male screw part 2d Bolt main body 3 Mold 3a Mounting hole 4 Nut 5 Holding body 6 Packing 6a Insertion hole 8 Concrete 9 Filling 101 Insert 102 Concrete structure Object 103 Holder 104 Breaking part 105 Joint 106 Formwork

Claims (3)

An insert fixture that is screwed into an insert for fastening a bolt embedded in a concrete structure, is inserted through a mold and attaches the insert to the mold before placing the concrete,
The insert fixture includes an attachment member that is screwed to the insert, a cylindrical holder that covers the periphery of the attachment member and is made of a material that is not compatible with concrete, and the attachment member is used as the mold. With a nut to fix,
An insert mounting tool, wherein an end of the mounting member on the mold side is provided with a screwing portion to be screwed with the nut and an engaging portion to be engaged with a removal tool.   The insert fixture according to claim 1, wherein the holding body is made of silicon.   The insert fitting according to claim 1 or 2, wherein the engaging portion is formed by cutting the screw thread of the screwing portion flat on two parallel surfaces.

Images