JP7409588B2 - Reinforced concrete structure through hole forming sleeve retention mechanism - Google Patents

Description

The present invention relates to a mechanism for holding a sleeve for forming through holes in beams, floors, and walls of a reinforced concrete structure in a formwork. The present invention also relates to a route identification method in piping and wiring work using this sleeve holding mechanism.

In construction work, sleeves are used to form through holes for passing equipment piping, electrical wiring, etc. through beams, floors, and walls of reinforced concrete structures. This sleeve is generally cylindrical in shape, and includes voids, which are paper cylinders that are removed after a curing period after pouring fresh concrete, pipes made of galvanized steel sheets, and pipes made of hard polyvinyl chloride, which are used as structures as they are. There is.

In order to form through holes in beams, floors, and walls at specified locations, it is necessary to fix this sleeve to the formwork before pouring fresh concrete, but in the case of voids, it is necessary to directly drive nails diagonally into the formwork. In the case of pipes made of galvanized steel sheets or hard polyvinyl chloride, the common construction method was to fix them with nailing fittings. This method had the advantage of being very simple and secure, but it also had some problems in construction. The biggest drawback was the workability of hammering the nails into the formwork. Another problem was the post-treatment of the nails.

When fixing a floor sleeve or wall sleeve to the floor or wall formwork, align the sleeve with the marked position, hold it with your hands to prevent it from moving, and then drive the nails using a tool such as a hammer or nailing bar. and was not easy to secure precisely in place. When fixing a sliding beam sleeve consisting of an inner cylinder and an outer cylinder to a beam formwork, first mark out the installation position when the beam formwork is completed. Next, the beam reinforcing structure is assembled on top of the beam formwork, and the beam sleeve is temporarily fixed there. The beam reinforcement structure is then dropped into the beam formwork. Only at that stage could the beam sleeve be fixed at the predetermined marking position, but the beam reinforcing structure took away spatial freedom and became an obstacle when using tools such as a hammer. As a result, work efficiency was reduced and labor was required.

When the formwork is taken apart after pouring fresh concrete, the tips of the nails that fixed the sleeve will stick out and remain on the structure, which is dangerous, so they must be removed using a tool such as a baby sander. did not become. Furthermore, it took time and effort to apply rust preventive to the cut surfaces of the nails.

In order to improve workability when fixing a sliding type beam sleeve to a beam formwork, a separate type beam sleeve was devised (see Patent Document 1). The beam sleeve is divided into the main body and the fixed part, which can be connected to each other.The sleeve fixed part can be nailed into the beam formwork before the beam reinforcing structure is dropped into the beam formwork, making work easier. It can be said that the quality has improved. However, the nails used for fixing remained on the frame, and the problem of post-treatment of the nails remained unresolved.

In addition, focusing on the same technical problem, a plate-type sliding beam sleeve fixing auxiliary fitting was devised (see Patent Document 2). A fixing hole is provided in the center of a metal plate processed into a circular shape, and a rectangular leaf spring is attached to the back side of the metal plate.The above problem is solved by integrating the beam sleeve with adhesive tape. In other words, before the beam reinforcing structure is dropped into the beam formwork, a nail is driven into the predetermined mounting position, and after the beam is dropped, the center hole of the auxiliary fitting integrated with the beam sleeve is inserted into the nail. It can be fixed by pushing in. It can be said that work efficiency has improved since nailing work is no longer required with spatial freedom deprived. However, preparation and post-processing required time and effort, such as integrating fixing auxiliary fittings and beam sleeves with adhesive tape, and removing them after pouring fresh concrete.

In order to solve other similar technical problems, a ring-shaped sliding beam sleeve fixing fitting was devised (see Patent Document 3). It can be said that workability has been improved by using a fixing method that uses a rotary insertion method between the inclined claw holder provided on the ring fitting for fixing the sleeve and the claw protrusion fitting provided on the sleeve. However, inclined pawl retainers and pawl protrusion metal fittings are easily deformed, and are particularly vulnerable to lateral displacement of the sleeve, which is a problem when pouring fresh concrete. Furthermore, when the formwork is taken apart after pouring, there is a high possibility that the ring fitting will separate from the sleeve and remain on the formwork side. If this happens, it will take time and effort to remove the ring fitting from the formwork material.

Furthermore, in response to a similar technical problem, a sliding sleeve equipped with a locking mechanism was devised (see Patent Document 4). A pair of cylindrical fixing holders are provided inside both ends of a sleeve body consisting of an inner tube and an outer tube, and a locking mechanism is provided to releasably fix these and both ends of the sleeve body. It can be said that work efficiency has improved because nailing work no longer requires spatial freedom and the problem of nail post-processing has been resolved. However, since the fixing holder has a cylindrical shape, there are disadvantages when trying to apply this to the construction of a floor sleeve. That is, if a fixing holder is attached to the floor formwork in advance, there is a high possibility that it will be damaged by being tripped over or kicked by workers such as reinforcing steel contractors. Furthermore, even when used for constructing beam or wall sleeves, the fixing holders may get caught when assembling the beam or wall reinforcing structure, or when dropping the beam reinforcing structure into the beam formwork. There is a high possibility that it will be damaged.

In addition to the construction problems mentioned above, there was another problem that needed to be improved in sleeve construction. In other words, there is a problem in identifying various types of sleeves such as sanitary, air conditioning, fire extinguishing, electrical, etc. When the formwork was taken apart after pouring fresh concrete, all the sleeves that appeared on the structure looked the same, and it was visually unclear which piping and wiring system each sleeve belonged to. . Therefore, it was necessary to proceed with the piping and wiring work while checking each sleeve one by one with the drawings. If it becomes clear, route identification during piping and wiring work will be obvious at a glance, and as a result, it will be easier to imagine the construction work.

Another issue I would like to improve is the inking on the sleeve. When installing a sleeve, it was necessary to mark out the formwork etc. in advance before placing the reinforcement, and to inform the reinforcing steel construction contractor of the sleeve construction schedule. In other words, by marking directly on the formwork with a marker, spray, etc., find the center position where the sleeve will be attached, draw a circle with the diameter size so that you can see the diameter, and then write the diameter, type of piping and wiring system, etc. I had to do it and it was time consuming. Furthermore, even if the markings were made, the way the markings were displayed varied widely depending on the worker, and there was a lack of uniformity, which often meant that the information was not conveyed clearly.

Utility model registration No. 3079850 Japanese Patent Application Publication No. 2004-250924 JP2007-92488A Japanese Patent Application Publication No. 2009-144465

The problem to be solved by the present invention is to provide a sleeve holder that is useful not only for beam sleeve construction, but also for floor and wall sleeve construction, and that is resistant to damage and has sufficient strength. The point is that it provides a mechanism. That is, an object of the present invention is to provide a sleeve holding mechanism that can easily fix a beam sleeve to a formwork even when spatial freedom is taken away by the beam reinforcing structure. To provide a sleeve holding mechanism that eliminates the need for complicated work such as nailing while holding the sleeve by hand when fixing the floor sleeve or wall sleeve to a formwork. Another object of the present invention is to provide a sleeve holding mechanism that does not cause the problem of post-treatment of nails that occurs when the formwork is taken apart after pouring fresh concrete. Furthermore, it is an object of the present invention to provide a sleeve holding mechanism that allows route identification in piping and wiring work to be made obvious at a glance. Furthermore, it is an object of the present invention to provide a sleeve holding mechanism that simplifies the labor involved in marking out sleeves and can uniformly and clearly transmit sleeve construction schedule information.

The sleeve holding mechanism according to the present invention solves these problems and is as follows. That is, the sleeve holding mechanism according to claim 1 is a rotation method in which a sleeve and a holding plate of a size that fits inside the sleeve are manufactured separately, and the sleeve and holding plate are connected or disconnected together. A means for engaging is provided between the inner circumferential side surface of the outer end of the sleeve and the outer circumferential side surface of the holding plate, and the means is used to connect or disconnect the two. The holding plate is fixed to the formwork by a fixture, and the ready-mixed concrete is poured with the sleeve and the holding plate integrally connected by the above-mentioned rotational engagement means. In this case, the fixing device has the function of firmly fixing the holding plate to the formwork and easily detaching from the formwork when the formwork is dismantled. The interlocking means exerts a holding force such that when the formwork is dismantled, the retaining plate comes off from the formwork together with the fixings and remains on the building frame together with the sleeve, and these fixings are The combination of this feature and the retaining force provided by the rotary engagement means allows the sleeve to be securely fixed to the formwork via the retaining plate, while also ensuring a secure hold when the formwork is dismantled after pouring fresh concrete. , the holding plate is removed from the formwork together with the fixture and remains on the frame side together with the sleeve.

Its major feature is that the fixing holder is plate-shaped rather than cylindrical. By making it thin like a plate, you can minimize the risk of it being caught or kicked by workers. In addition, by making the sleeve into a plate shape, for example, if the means of connection between the sleeve and the fixed holder is a method of interlocking protrusions and grooves, the grooves can be dug deep, and the protrusions provided on the sleeve can also be made to match this. Since the width and bulk can be made wider and taller, as a result, the groove can be engaged with the groove in surface contact, and the impact resistance can be improved. Therefore, it is widely applicable not only to the construction of sliding beam sleeves consisting of an outer cylinder and an inner cylinder, but also to the construction of floor and wall sleeves where the sleeve is attached as a single unit.

Furthermore, the plate shape reduces the risk of breakage and allows the fixed holder to be used as a marking means. In other words, by attaching retaining plates to the sleeve installation positions on not only beam formwork, but also floor and wall formwork before reinforcing reinforcement, reinforcing steel contractors etc. can easily identify the sleeve installation position and caliber. , the type of piping and wiring system, and other information on the sleeve construction schedule can be clearly communicated visually. As a result, the entire work at the site flows smoothly.

When fixing floor sleeves and wall sleeves to formwork, for example, if nails are used as the fixing device, nail the retaining plate to the marked position of the formwork before installing the reinforcing bars. Once assembled, it can be easily fixed by connecting the sleeve and the holding plate. When fixing the sliding beam sleeve to the formwork, do the following: First, nail the retaining plates to the marked positions on the left and right sides of the beam formwork. Next, after the beam reinforcing structure is assembled on the top of the beam formwork, the beam sleeve is temporarily fixed. Then, once the beam sleeve is dropped into the beam form together with the beam reinforcing structure, the temporary fixation can be released, the outer cylinder and inner cylinder can be stretched, and they can be fixed by connecting them with the left and right holding plates respectively. . Even in a state where spatial freedom is taken away by the beam reinforcing structure, there is no need to use tools such as a hammer, so work efficiency is improved.

In the sleeve holding mechanism according to claim 2, the means for integrally connecting and disconnecting the sleeve and the holding plate includes a protrusion and a groove that can be rotationally engaged with each other on the inner side of the outer end of the sleeve. It is characterized in that it is provided on the circumferential side surface portion and the outer circumferential side surface portion of the holding plate. At this time, the protrusion may be provided on the sleeve and the groove may be provided on the holding plate, or vice versa.

Various other means are conceivable for integrally connecting or disconnecting the sleeve and the holding plate. For example, male and female threads that can be engaged with each other may be provided on the inner circumferential side surface of the outer end of the sleeve and the outer circumferential side surface of the retaining plate, or holes and leaf spring-type protrusions that can be engaged with each other may be provided. This is a method to set it up.

The key point is that when the formwork is taken apart after pouring fresh concrete, the retaining plate fixed with nails will come off the formwork and remain integrated with the sleeve, exerting a holding force that can be easily released. Some means of connection may be provided on both the sleeve and the retaining plate.

However, the present invention aims to apply the holding plate not only to beam sleeve construction but also to floor and wall sleeve construction in a wide range of sleeve construction, and emphasizes impact resistance. Therefore, from the viewpoint of improving impact resistance, the present invention mainly uses a method of interlocking protrusions and grooves, a method of interlocking grooves, or a method of interlocking screws as a means of connecting the sleeve and the holding plate. It was designed with this in mind. That is, it is an essential condition that protrusions and grooves, grooves and grooves, male threads and female threads, etc., which can realize surface-to-surface engagement can be formed on both the sleeve and the holding plate. Therefore, it is difficult to achieve meshing through surface contact with the method of fitting holes and leaf spring type protrusions, in which a hole is provided on the side surface of the sleeve and a leaf spring type protrusion is provided on the outer peripheral side surface of the retaining plate. Therefore, it can be said that it is not suitable as a means for connecting the sleeve and the holding plate of the present invention. In addition, although the screw engagement method has the advantage of being excellent in impact resistance in all directions, the retaining plate must be thick enough to form a spiral groove, so the retaining plate must be made as thin as possible. In the present invention, which is intended to do so, it is difficult to say that it is superior to a method in which projections and grooves are engaged, or a method in which grooves are engaged with each other.

The retaining plate is thick enough to form grooves, protrusions, screws, etc. on the outer peripheral side surface, and when it engages with the sleeve, it acts from the inside and exerts a strong force to prevent the sleeve from shifting laterally. Therefore, it can withstand shock and vibration during pouring of fresh concrete. When the formwork is dismantled after pouring fresh concrete, the retaining plate and the fixing nails naturally come off the formwork and remain on the frame together with the sleeve. Therefore, there is no need to take the trouble of removing the holding plate from the formwork material later. Moreover, the holding plate can be easily removed by releasing the connection with the sleeve. At that time, the fixing nails are also removed. Therefore, the holding plate can be reused, which is economical, and there is no problem with post-treatment of nails.

In the sleeve retaining mechanism according to claim 3, the retaining plates are made of synthetic resins of different colors , the retaining plates are color-coded for each piping and wiring system, and the retaining plates are fixed to the sleeve attachment position of the formwork with a fixture before reinforcing. This allows the holding plate to be used as a means of marking to convey information on the type of sleeve to be installed, as well as to indicate which piping and wiring system the sleeve to be installed belongs to, as well as to indicate the type of sleeve to be installed. When the formwork is dismantled, the retaining plate remains on the frame together with the sleeve, and can also be used as a means of route identification in piping and wiring work. The retaining plates used in sleeve construction can be color-coded for different piping and wiring systems, such as sanitary, air conditioning, fire extinguishing, electrical, etc., and they will be integrated with the sleeve when the formwork is taken apart after pouring fresh concrete. Since the pipe remains inside the structure, route identification during piping and wiring work becomes obvious. Furthermore, when marking the sleeve, simply by hammering the holding plate against the formwork, the type information of the piping and wiring system can be conveyed in color rather than in text, making marking visually clear.

By making the fixed holder plate-shaped instead of cylindrical, the present invention can be widely applied not only to beam construction but also to floor and wall construction, and the holding plate can be used in common for all sleeve construction. can. Therefore, demand is expected to be significant, and if the holding plate is made of thermoplastic resin such as polypropylene or ABS, it will be suitable for mass production by injection molding, etc., and costs can be reduced significantly.

In addition, the sleeve holding mechanism according to the present invention has three or more protrusions and grooves provided on the sleeve and the holding plate at equal intervals on the circumference, or three or more protrusions and grooves are provided on the sleeve and the holding plate at key points on the circumference. It is desirable to have at least one location. In sleeve construction, especially in the case of floor or wall sleeves, which are installed as a single sleeve, the sleeve may be subject to lateral impact loads such as being tangled with a vibrator hose and being pulled by a vibrator hose or being kicked by a worker during pouring of fresh concrete. easy to receive. The protrusions and grooves provided on the sleeve and retaining plate engage with each other at three or more equally spaced locations on the circumference, or at three or more key locations on the circumference, providing impact resistance in all directions. can be improved.

It is also desirable that the holding plate has one or more fixing insertion holes at important points, or that the holding plate has fixing insertion holes and is pre-installed with fixing devices. . For example, when the fixing device is a nail, workability can be improved by providing a nail hole or installing a metal nail, resin nail, etc. therein in advance. In the present invention, the fixing device is mainly assumed to be a nail, but any fixing device that can securely fix the holding plate to the formwork and has the function of easily coming off from the formwork when the formwork is taken apart may also be used. However, it may be optional.

Further, it is preferable that a fixing device insertion hole is provided near the end of the groove in the holding plate, or that a fixing device insertion hole is provided and a fixing device is installed in advance. In the present invention, since the fixing holder is not cylindrical but plate-shaped, for example, if the fixing tool is a nail, the position of the nail when fixing the holding plate to the formwork becomes very important. That is, by fixing near the groove end point, deformation of the holding plate due to impact can be suppressed as much as possible, and impact resistance can be improved. Furthermore, when the formwork is taken apart after pouring fresh concrete, the fixing nails tend to come off naturally from the formwork.

Furthermore, it is preferable that the holding plate has one or more openings at key points, or that the holding plate is ring-shaped. When pouring ready-mixed concrete, a separator is attached to hold the formwork, but it may penetrate the inside of the sleeve. Therefore, one or more openings may be provided at important points in the holding plate to allow the sepa to pass through. These openings also serve as a handhold when releasing the retaining plate from the sleeve, and their provision also saves material.

The shape of the holding plate may be arbitrary as long as it is large enough to fit inside the sleeve and can be connected to the inner circumferential side surface of the outer end of the sleeve, but a ring shape in particular has various advantages. to be born. For example, if a ring-shaped retaining plate is nailed to the formwork during marking, it will be easier for reinforcing contractors to imagine that a cylindrical sleeve will be installed there, and it will also make it easier to visually identify the diameter of the sleeve. be able to communicate clearly. In addition, especially when manufacturing a holding plate for a large-diameter sleeve, using a ring shape can save a lot of material. Furthermore, since the opening is large, the allowable range for the separation to escape is widened, making construction easier.

In addition, an opening is provided in the center of the holding plate, and a plate-like member extending from the holding plate to the center is provided in the opening, and the vicinity of the tip is hollowed out, and the center of the holding plate is hollowed out. It is desirable that the hole be aligned with the center of the hole, so that it can function as a matching hole. When inking, as long as you get the ink in the center of the sleeve, all you have to do is align the ink alignment hole with it and hit the holding plate to complete the inking. In addition, since the visibility near the center of the holding plate is maximized, it is easy to perform inking work.

In the sleeve holding mechanism according to claim 3, the holding plate may be replaced with a fixed holder. The shape of the fixing holder is large enough to fit inside the sleeve, and if it has a function that allows it to be connected or disconnected by means of rotational engagement with the inner circumferential side surface of the outer end of the sleeve, the plate It may be in any shape, such as cylindrical, cylindrical, or cylindrical.

In the present invention, we believe that making the fixing holder into a plate shape is the most versatile sleeve construction method from the viewpoint of reducing the risk of breakage or improving impact resistance. However, even if the fixing holders have other shapes, such as cylindrical or cylindrical, it is recommended that they be manufactured from synthetic resins of different colors so that they can be installed in different colors depending on the piping and wiring system. There is no doubt that it is useful. It is desirable that all fixed fixtures for beams, floors, and walls used in sleeve construction be color-coded. Being able to see at a glance which piping and wiring system all the sleeves used on site belong to will help each contractor proceed with piping and wiring work smoothly. It is in the interest of the entire field.

A method for constructing a sleeve according to claim 4 is characterized in that the sleeve holding mechanism according to any one of claims 1 to 3 is used.

By using the sleeve holding mechanism according to the present invention, it becomes possible to accurately and easily fix the sleeve at a predetermined position on the formwork. This eliminates the problem of post-processing nails on the frame. The holding plate or fixed holder plays the role of route identification during piping and wiring work, making it easier to visualize the construction work. This simplifies the time and effort required to mark out sleeves, and it also becomes possible to uniformly and clearly communicate sleeve construction schedule information.

FIG. 2 is a perspective view of a sleeve showing a form for carrying out the present invention. It is a perspective view of a holding plate similarly. It is also an explanatory diagram of sleeve construction. It is a perspective view of a beam sleeve similarly. Similarly, it is a procedure explanatory diagram of beam sleeve construction. 3 is a perspective view of a holding plate showing Example 1. FIG. FIG. 3 is a perspective view of a holding plate showing Example 2. FIG. 7 is a perspective view of a sleeve showing Example 3. FIG. 7 is a perspective view of a holding plate showing Example 3.

Embodiments for carrying out the present invention will be explained based on FIGS. 1 to 5. 1 in FIG. 1 shows a cylindrical sleeve. Three protrusions 2 are provided at equal intervals on the inner peripheral side surface of the outer end of the sleeve 1. 3 in FIG. 2 shows a disk-shaped holding plate. Three notches 4 are provided at equal intervals on the outer peripheral side surface of the holding plate 3. Furthermore, arc-shaped grooves 5 continuing from the notch portions 4 are provided, and are adapted to be engaged with the projections 2 of the sleeve 1 via groove introduction portions 5a. On the other hand, a nail hole 6 is provided in the center of the holding plate 3.

FIG. 3 shows a construction method for installing a floor/wall sleeve using the sleeve 1 and the holding plate 3. First, before reinforcing bars are set in the formwork 7, marking is done, and the holding plate 3 is fixed by nailing it to the formwork 7 with nails 8 through the nail holes 6. Next, when the reinforcing bars are assembled, the projections 2 of the sleeve 1 are fitted into the groove introducing portions 5a of the holding plate 3. By further rotating the sleeve 1 toward the groove end point 5b, the protrusion 2 and the groove 5 engage and the connection is completed.

9 in FIG. 4 shows a sliding beam sleeve. The beam sleeve 9 consists of an inner tube 9a and an outer tube 9b, which can slide and expand and contract when combined with each other. Three protrusions 2 are provided at equal intervals on the inner peripheral side surfaces of the outer ends of the inner cylinder 9a and the outer cylinder 9b, respectively, and can be connected to the holding plate 3 in the same manner as the sleeve 1.

Figure 5 shows the actual construction procedure for beam sleeve installation work. Construction is carried out using two holding plates 3. Explaining step by step from A to F in Figure 5,
A. The sleeve attachment position of the beam formwork 10 is marked, and before the beam reinforcing structure 11 is assembled, the two holding plates 3a and 3b are fixed with nails 8a and 8b, respectively.
B. Once the beam reinforcing structure 11 is assembled on the upper part of the beam formwork 10, the beam sleeve 9 is temporarily fixed therein.
C. When the beam sleeve 9 is dropped into the beam formwork 10 together with the beam reinforcing structure 11, the temporary fixation is released and stretched, so that the protrusions 2 of the inner tube 9a and outer tube 9b are aligned with the groove introducing portions 5a of the holding plates 3a and 3b. Make sure they fit into each.
D. The inner tube 9a and the outer tube 9b are rotated toward the groove end points 5b of the holding plates 3a and 3b, respectively, and the connection is completed.
E. When the beam formwork 10 is dismantled after pouring fresh concrete, the holding plates 3a and 3b are removed from the beam formwork 10 together with the nails 8a and 8b, and remain in the inner tube 9a and the outer tube 9b.
F. The groove introducing portions 5a of the holding plates 3a, 3b are rotated so as to align with the protrusions 2 of the inner cylinder 9a, outer cylinder 9b to release the connection, and the holding plates 3a, 3b are removed from the beam sleeve 9. At this time, the nails 8a and 8b are also removed together.

Example 1 will be described based on FIG. 6. In the first embodiment, an opening 13 is provided in the center of the holding plate 3. Further, the opening 13 is provided with a plate-like member 14 extending from the holding plate 3 to its center, and the vicinity of its tip is hollowed out in a circular shape so that its center coincides with the center of the holding plate 3. , functions as a black matching hole 15. Nail holes 6 are provided near the three groove end points 5b, respectively. When a separator for holding the formwork passes through the inside of the sleeve, the separator can escape through the notch 4 or the opening 13.

Example 2 will be described based on FIG. 7. In the second embodiment, the holding plate 3 is ring-shaped. The larger the opening 13 is, the wider the allowable range in which the sepa can escape. It also saves materials, so it is economical when used for large-diameter sleeve construction. In the vicinity of the three groove end points 5b, cylindrical nail receiving seats 16 and nail holes 6 passing through the center and the holding plate 3 are provided, and nails 8 are installed therein.

Example 3 will be described based on FIGS. 8 and 9. In the third embodiment, as shown in FIG. 8, the protrusion 2 provided on the sleeve 1 is made wider to further improve impact resistance. Accordingly, the holding plate 3 also has a wide notch 4 as shown in FIG. However, on the side to be fixed to the formwork, the holding plate 3 is left without notches to minimize the intrusion of fresh concrete and the like. The sleeve 1 is manufactured by processing a galvanized steel plate. The three protrusions 2 require spot welding by fitting an L-shaped member 18 made of galvanized steel plate, in which the protrusions 2 and the protrusion support piece 17 are integrally molded, from the outer circumferential side of the sleeve 1 through the protrusion fitting holes 19. It is formed by applying it in places. The thickness of the protrusion 2 is about 1 mm, but since it is made of a galvanized steel plate, it has sufficient strength. As a result, the thickness of the groove 5 provided in the holding plate 3 is only about 1 mm, and the finished thickness of the holding plate 3 is about 6 mm. This thickness reduces the risk of damage due to being caught by a worker's foot or being kicked, and the holding plate 3 can be used in all types of sleeve construction for beams, floors, and walls. The holding plate 3 is made of polypropylene, and can absorb shock by being slightly elastically deformed.

The protrusion 2 provided on the sleeve 1 may be formed by manufacturing the sleeve 1 and the protrusion 2 as separate members made of galvanized steel sheets as described above, and then forming them integrally. Alternatively, the protrusion 2 may be formed directly on the sleeve 1 by stretch molding or the like. It may also be made to protrude. Alternatively, the sleeve 1 and the protrusion 2 may be formed by punching out a galvanized steel plate and then performing various processes such as bending, various forming processes, and spot welding. Alternatively, the protrusion 2 may be made of synthetic resin and may be formed by fitting it into the sleeve 1 through the protrusion fitting hole 19 or by bonding it. The material of the sleeve 1 may be made of galvanized steel plate as described above, or may be made of any material suitable for sleeve construction such as hard polyvinyl chloride.

1 Sleeve 2 Protrusions 3, 3a, 3b Holding plate 4 Notch 5 Groove 5a Groove introduction part 5b Groove end point 6 Nail hole 7 Formwork 8, 8a, 8b Nail 9 Beam sleeve 9a Inner cylinder 9b Outer cylinder 10 Beam formwork 11 Beam reinforcing structure 12 Concrete frame 13 Opening 14 Plate member 15 Matching hole 16 Nail receiver 17 Projection support piece 18 L-shaped member 19 Projection fitting hole 20 Spot welding part

Claims (4)

A sleeve and a retaining plate large enough to fit inside the sleeve are manufactured separately, and a rotary engagement means for connecting and disconnecting the sleeve and retaining plate is installed inside the outer end of the sleeve. A sleeve holding mechanism is provided between the peripheral side surface and the outer peripheral side surface of the holding plate, and is used to connect or disconnect the two, and the holding plate is attached to the formwork. The sleeve and its holding plate are fixed together by a fixing device, and the ready-mixed concrete is poured with the sleeve and its holding plate integrally connected by the above-mentioned rotational engagement means, and at this time, the fixing device The plate can be securely fixed to the formwork, and it also has the function of easily coming off naturally from the formwork when the formwork is dismantled; Sometimes, the retaining plate comes off the formwork together with the fixings and remains on the building body as a unit with the sleeve, exerting a holding force. The combination of the retaining force provided by the means allows the sleeve to be securely fixed to the formwork via the retaining plate, and when the formwork is dismantled after pouring the fresh concrete , the retaining plate together with the fixings retains the formwork. A sleeve retention mechanism that is detached from the sleeve and remains on the body side as an integral part of the sleeve. The means for integrally connecting and uncoupling the sleeve and the retaining plate includes a protrusion and a groove that can be rotationally engaged with each other on the inner circumferential side surface of the outer end of the sleeve and the outer circumferential side surface of the retaining plate. 2. The sleeve holding mechanism according to claim 1, wherein said sleeve holding mechanism is provided at said sleeve holding mechanism. By making the retaining plates from synthetic resins with different colors, color-coding the retaining plates for each piping wiring system, and fixing them with fixtures at the sleeve installation positions on the formwork before reinforcing, it is possible to identify which piping the sleeve will be installed on. Perhaps it belongs to the wiring system, but the holding plate can be used as a means of marking to convey information on the type of sleeve to be constructed, and when the formwork is dismantled after pouring fresh concrete. The sleeve holding mechanism according to claim 1 or 2, wherein the holding plate that remains on the body side integrally with the sleeve can also be used as a means for route identification in piping and wiring work. . A method for constructing a sleeve, the method comprising using the sleeve holding mechanism according to any one of claims 1 to 3.

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