KR102147383B1 - Column shear strength reinforcing method and its reinforcing device - Google Patents

Abstract

The present invention relates to a method and an apparatus for reinforcing the shear capacity of a pillar. According to the present invention, the method for reinforcing the shear capacity of a pillar comprises: an adhesive applying step; a bracket fixing step; a reinforcing wire material constructing step; a first connecting step; a tension adjusting step; a protection plate installing step; and a filling step. According to the present invention, a building can be prevented from collapsing and being damaged.

Description

Column shear strength reinforcing method and its reinforcing device

The present invention relates to a column shear strength reinforcing method and a reinforcing device thereof.

More specifically, a column shear strength reinforcement method that protects the building from earthquakes as well as vibrations acting on the building by reinforcing the column shear strength of the building, and reinforces the column to withstand various loads applied to the column. And it relates to the reinforcing device.

In addition, the present invention relates to a column shear strength reinforcing joint and a reinforcing device for preventing loss of property as well as personal injury due to a collapse of a building by reinforcing a column of an existing building, and ensuring safety.

In general, a building consists of a plate-shaped or block-shaped structure, and a column that physically supports the structures located above. Therefore, the pillars of a building must be able to withstand the load of the structure and other loads applied on it sufficiently, and must be able to withstand the external force applied in the horizontal direction such as earthquake or wind pressure, and if not, there is a risk of collapse. .

Recently, various construction methods for reinforcing pillars have been proposed in consideration of safety along with concerns about earthquakes. For example, there are a cross-section extension reinforcement method, a carbon fiber reinforcement method, and a steel plate reinforcement method.

The double section extension reinforcement method is to reinforce the section by anchoring the fixing member to the column and pouring reinforced concrete outside. However, in the method of reinforcing section extension, it is necessary to maintain the mortar spacing required for section extension, anchor the fixing member to the pillar, and roughly chipping the pillar surface to improve adhesion, which damages the structure, and scatters dust in the process of treating the pillar surface. Occurs, there is a problem that the working environment is poor.

The carbon fiber reinforcement method is a method capable of expressing high strength and high durability by arranging carbon fibers having excellent tensile strength in one direction and forming a sheet, which is impregnated with an epoxy resin on the concrete surface to adhere and cure. However, the carbon fiber used in the carbon fiber reinforcement method has a disadvantage in that it is weak in fire resistance because epoxy, which is a non-combustible material or an adhesive for attaching carbon fiber, is weak to heat.

Recently, a concrete structure reinforcing device and a reinforcing method using the same have also been developed as in Registration Patent No. 10-1499820.

This device is a device for reinforcing to prevent shear deformation of a concrete structure by an external force, comprising: a wire rod support portion disposed at a corner where a flat portion of the structure and another flat portion adjacent to each other meet each other; A wire rod mounted on the wire rod support and disposed outside the structure; And an external force applying portion disposed on any one of a plurality of flat portions of the structure, each of which ends of the wire rod are connected to apply a tensile force of a certain strength to the wire rod; including one end of the wire rod to the outside. Reinforcement by applying a binding force acting in the direction of the center of the cross section orthogonal to the structure through a pre-tension force applied to the wire rod by pulling,

The external force application unit has first and second through holes in the center of the body through which one end and the other end of the wire is penetrated, and the outer surface of one end and the other end to which the first and second locking holes provided at one end and the other end of the wire are disposed. A first and second connector having first and second male threads respectively formed therethrough, and a wire coupler in which a female screw hole through which each of the first and second male threads is screwed to both ends is formed through the center of the body,

By rotating the first and second connectors in the locking direction, an external force is applied to the wire rod by narrowing the gap between the first and second engaging sections.

However, such a reinforcing device also has several problems. Since the wire rod support part and the external force human part are configured separately, there is an inconvenience of having to install and install each one each time a wire rod is constructed, and there is also a risk of a safety accident as the wire rod support protrudes to the outside after construction.

The present invention has been made in view of such a conventional problem, the purpose of which is to facilitate construction, to ensure that the wire rod has sufficient tensile force and to adjust the tension, and to prevent collapse and damage of the building in preparation for external forces such as earthquakes. By doing so, it is to provide a column shear strength reinforcing method and a reinforcing device thereof that can prevent damage to property and people.

The present invention is a method of reinforcing the girdle of a building structure to withstand vibration and earthquakes, comprising: grinding the outer wall of the column by grinding, and applying an adhesive to the surface; A column reinforcement preparation step in which holes are formed at equal intervals in the reinforcing plate of the bracket having a flat cross-section of "a" shape, and the adjacent fixing plate is adhered to the adhesive, and is installed symmetrically around each corner of the column; A bracket fixing step of drilling an anchor hole in the bracket and the column, and driving and fixing an anchor in the anchor hole; As a reinforcing wire construction step of reinforcing the pillar by inserting a reinforcing wire rod into the hole of the bracket installed at each end of one side of the pillar, inserting the first wire into the hole of the one bracket, and inserting a second wire into the hole of the other bracket. The step of inserting the wire rod; An installation step of installing a pulling unit consisting of upper and lower gears into the first adjustment unit into which the first wire is inserted; And an assembling step of inserting the screw part of the first wire into the first adjusting part and then fastening the nut to assemble, and the second wire having the stepped surface on which the unidirectional protrusion is formed in the second adjusting part. The second adjusting part is inserted into the first adjusting part, and a magnet provided in the first adjusting part pulls and connects the second adjusting part by magnetic force, and the stepped surface of the second wire inserted in the second adjusting part is connected to the first adjusting part. A primary connection step fitted between the installed upper and lower gears; After the first connection, an inspection step of checking the number, position and spacing of reinforcing wires; And a binding step of pressing the fixing pin provided in the first adjusting part to bind the first adjusting part and the second adjusting part. A tension adjusting step of pulling the reinforcing wire in tension by rotating a rotation shaft of one of the gears of the pulling unit; A protective plate installation step of enclosing the brackets disposed on both sides of the pillar with a protective plate to protect the bracket from external shocks and protruding from the corners to protect them when a pedestrian or vehicle collides; It has a technical feature consisting of; a filling step of filling a filler in which urethane, a curing agent, and water are mixed into the protective plate.

The present invention is an invention that prepares for an earthquake that cannot be called a safe zone even in Rina, and protects a building structure to withstand vibration in the event of an earthquake so that there is no damage to property and human life.

In addition, the present invention is an invention having the effect of being easy to construct by simple operation, allowing the wire rod to have sufficient tensile force, adjusting the tension, and making replacement easy.

1 is a perspective view of a shear strength reinforcing device according to the present invention,
2 is a plan view of the shear strength reinforcing device according to the present invention,
3 is an enlarged perspective view of a main part of the reinforcing device according to the present invention,
Figure 4 is a perspective view showing another embodiment of the pillar shear strength reinforcing device according to the present invention,
5 and 6 are perspective views showing another embodiment of a reinforcing device according to the present invention,
7 is a cross-sectional view of a part of a reinforcing device according to the present invention,
8 is an enlarged cross-sectional view of a main part of a reinforcing device according to the present invention,
9 and 11 are cross-sectional views showing an example of an adjustment device applied to the present invention;
12 is a cross-sectional view showing another embodiment of the present invention.

In describing the embodiments of the present invention, the same symbols mean the same configuration, and additional descriptions that may be redundant or limitedly interpret the meaning of the invention may be omitted in describing the embodiments of the present invention.

Prior to the detailed description, the concept of the invention in light of the environment in which the singular/plural is not clearly distinguished in the use of the Korean language and the environment in which the terms are used in the related field, even if it is described in a singular expression in this specification. It is used as a meaning that includes plural expressions unless it is contradictory in interpretation and does not mean clearly differently. In addition,'includes','have','includes','consists of,' and the like described or may be described in this specification indicate the presence or addition of one or more other features or elements or combinations thereof. It should be understood that it is not excluded in advance.

First, Figure 1 attached to the present invention is a perspective view of a shear strength reinforcing device according to the present invention, Figure 2 is a plan view of the shear strength reinforcing device according to the present invention, Figure 3 is an enlarged perspective view of the main part of the reinforcing device according to the present invention Figure 4 is a perspective view showing another embodiment of the column shear strength reinforcing device according to the present invention.

5 and 6 are perspective views showing another embodiment of a reinforcing device according to the present invention, and FIG. 7 is a cross-sectional view showing a part of the reinforcing device according to the present invention, and FIG. 8 is a view of the reinforcing device according to the present invention. 9 and 11 are cross-sectional views showing an example of an adjustment device applied to the present invention, and FIG. 12 is a cross-sectional view showing another embodiment of the present invention.

Hereinafter, a preferred embodiment of the present invention will be described.

From a single point of view, it is a construction method to withstand vibration and earthquake by reinforcing the splint of a building structure.

Grinding the outer wall of the column by grinding and applying an adhesive to the surface; A column reinforcement preparation step in which holes are formed at equal intervals in the reinforcing plate of the bracket having a flat cross-section of "a" shape, and the adjacent fixing plate is adhered to the adhesive, and is installed symmetrically around each corner of the column; A bracket fixing step of drilling an anchor hole in the bracket and the column, and driving and fixing an anchor in the anchor hole;

As a reinforcing wire construction step of reinforcing the post by inserting a reinforcing wire into the holes of the bracket installed at each end of one side of the post,

A wire rod fitting step of inserting the first wire rod into the hole of the one side bracket and inserting the second wire rod into the hole of the other side bracket;

An installation step of installing a pulling unit consisting of upper and lower gears into the first adjustment unit into which the first wire is inserted; And

An assembly step of inserting the screw part of the first wire into the first adjusting part and then assembling by fastening the nut, and assembling the second wire by inserting the step surface on which the unidirectional protrusion is formed into the second adjusting part;

The second adjusting part is inserted into the first adjusting part, and a magnet provided in the first adjusting part pulls and connects the second adjusting part by magnetic force, and the stepped surface of the second wire inserted in the second adjusting part is connected to the first adjusting part. A primary connection step fitted between the installed upper and lower gears;

After the first connection, an inspection step of checking the number, position and spacing of reinforcing wires; And a binding step of pressing the fixing pin provided in the first adjusting part to bind the first adjusting part and the second adjusting part.

A tension adjusting step of pulling the reinforcing wire in tension by rotating a rotation shaft of one of the gears of the pulling unit;

A protective plate installation step of enclosing the brackets disposed on both sides of the pillar with a protective plate to protect the bracket from external shocks and protruding from the corners to protect them when a pedestrian or vehicle collides;

It consists of a; filling step of filling a filler mixed with urethane, a curing agent, and water into the protective plate.

On the other hand, the reinforcing device 100 according to the present invention is to prepare for earthquakes and vibrations by reinforcing the pillars in the transverse and longitudinal directions, and brackets 200 installed at each corner of the pillars, and fitted to the brackets. Consisting of a reinforcing wire 300, an adjustment device 400 for pulling the reinforcing wire 300 to maintain a tension state, and a protective plate 500 that is assembled to the bracket to prevent damage to the vehicle or injury when a pedestrian hits it. And here, the filler 600 and the buffer unit 700 is further provided.

Bracket (200)

The bracket 200 applied to the present invention comprises a fixing plate 210 that is abutted to the pillar 10, and a reinforcing plate 220 that maintains the tension of the reinforcing wire while the reinforcing wire is fitted in a "b" shape. do.

Preferably, the bracket 200 is made of a steel plate and has a length to which at least three or more reinforcing wires can be connected at equal intervals, and the column can be reinforced in the transverse and longitudinal directions together with the reinforcing wire.

The bracket 200 according to the present invention may be constructed by bending a steel plate with a press or manufactured by welding two steel plates, and an anchor 120 is inserted into the fixing plate 210 so that it can be fixedly installed on a column. The hole 212 is perforated, and a hole 222 into which the reinforcing wire is inserted in the longitudinal direction is perforated in the reinforcing plate 220.

Here, three or more holes 222 are perforated at equal intervals so that the reinforcing wires are selectively fitted.

On the other hand, the bracket 200 according to the present invention is installed on each side edge of the pillar. That is, the reinforcing wire 300 is inserted in each of the brackets 200 disposed on both sides of one side of the column 10 to be disposed on each side close to the corner of the column, and the adjustment device described later located in the center of the column 10 is used. This is to adjust the tension by pulling the reinforcing wire.

Reference numeral 224 denotes a groove in which the protective plate is fitted.

Reinforcement wire (300)

The reinforcing wire 300 according to the present invention may be composed of a steel wire, reinforcing bar or wire, and is composed of a first wire 320 and a second wire 340.

The first wire 320 has a head portion 321 on one side and a screw portion 322 at the other end thereof, and the screw portion has a length adjustment function and is inserted into the first adjustment portion to fasten a nut. Is assembled into

The second wire 340 is provided with a threaded portion 342 for length adjustment like the first wire on one side, and the opposite side constitutes a vertical smooth stepped surface 344 by press processing, and the smooth stepped surface 344 It is to form a unidirectional protrusion 346 so that the wire rod can be pulled.

Here, the unidirectional protrusion 346 is easily fitted when fitted with an adjustment device to be described later and does not fall out on the contrary. That is, it is composed of an inclined surface and a vertical surface.

Adjuster 400

The adjusting device 400 according to the present invention reinforces the column by pulling the reinforcing wire 300 to maintain a tensioned state, and is composed of a first adjusting part 420 and a second adjusting part 440.

The first adjustment part 420 is assembled by inserting the first wire 320, and a fitting hole 422 into which the threaded part 322 of the first wire 320 is fitted is formed on one wall surface 421 In addition, a stopper 424 is provided inside the first adjustment unit 420 to fix the position when the second adjustment unit 440 is fitted and to facilitate the fitting.

The wall surface 421 is formed only about 1/2 as shown in the drawing, and the lower side of the wall is opened. When the reinforcing wire 300 is tightened through the opening 423, the second wire 340 can be released. Is to do.

Meanwhile, the stopper 424 is provided with a magnet 425 so that it can be easily assembled by pulling it with magnetic force when the second adjusting part 440 is inserted, and the first connection, that is, temporarily, the first adjusting part and the second By connecting the control part, it is possible to check the spacing of the reinforcing wire, the number of the number suitable for the size of the column, etc., and then pull the reinforcing wire.

The second adjustment part 440 has walls 443 on both sides, a lead-in part 441 into which a second wire is inserted is provided in one wall, and a second wire inserted in the opposite wall 443 is provided. The outlet 442 is provided, but protrusions 444 corresponding to the one-way protrusions are provided on the inner upper and lower portions of the outlet 442 so that when the second wire 340 is fitted, it is easily fitted, and in the opposite direction It is not to fall out.

Reference numeral 460 denotes a fixing pin. This fixing pin allows the operator to press the fixing pin 460 after inspection in a state in which the second adjustment part 440 is first connected to the first adjustment part 420 so that the first adjustment part and the second control part are connected. will be.

To this end, a slide hole 462 through which the fixing pin moves is formed in the first control part, and a fitting hole 464 is provided in the second control part, and the fixing pin 460 has a head part to prevent it from being disassembled. It is to be able to hold and pull out the fixing pin.

Pulling part (450)

The pulling part 450 according to the present invention is to generate tension by pulling the reinforcing wire 300 and to reinforce the column by maintaining a tension state, and is installed inside the first adjusting part 420 to provide a second wire. Is to pull.

The pulling portion 450 is composed of a binding plate 451 and an auxiliary plate 451a installed at a distance from the binding plate 451, and a pair of upper and lower gears 460 is disposed therebetween.

The binding plate 451 is fixed to the wall surface of the first adjustment unit 420, and a shaft hole 452 into which the rotation shaft of the gear is fitted is formed in each of the upper and lower portions, and the shaft hole 452 is formed to the side. The pin hole 454 is formed so that the locking pin 456 that prevents the movement of the two wire rod 340 is inserted.

The auxiliary plate 451a has a lower end configured in the form of a rail 456a so that it is assembled by fitting to the locking member 402 provided on the bottom of the first adjustment unit 420, and this configuration can be separated if necessary. This is to make it possible. This will be described later.

Like the binding plate 451, a shaft hole 452a is formed in the upper and lower portions of the auxiliary plate 451a, and a pin hole 454a is formed next to the shaft hole.

The gear 460 is composed of upper and lower gears 462 and 464, the upper gear is assembled in a shaft hole formed on each of the auxiliary plate and the binding plate, and the lower gear is assembled in the shaft hole formed on the lower side.

Here, the rotation shaft 466, which is the rotation center of the gear 260, is preferably configured separately, and is assembled through the auxiliary plate, gear, and binding plate when assembling, and the end protruding outside the auxiliary plate is a square or hexagonal wrench. It is configured in a shape, and a separate tool is inserted and rotated to pull the second wire, and the central part of the rotation shaft is also configured in a quadrangular, polygonal, or splined shaft shape.

The pulling part 450 according to the present invention made of such a configuration may be installed inside the first control part 420 as a built-in, but it is preferable to be configured as an assembly type.

First, the operator assembles by fitting the upper gear 462 and the lower gear 462 on the inner surface of the auxiliary plate 451a, inserting the rotation shaft 466 into the shaft hole 452a, and passing through the shaft hole formed in the center of the gear. Assemble the gear to the auxiliary plate by inserting the rotation shaft only to the extent that it does not protrude from the gear.

Then, by using the rail 456a formed under the auxiliary plate 451a to fit into the bottom of the first adjustment unit 420, and push the rotation shaft 466 protruding out of the auxiliary plate 541a, the end of the rotation shaft is The gear is assembled by being inserted into the shaft hole 452 formed in the binding plate 451. Conversely, when disassembling, the rotation shaft 766 is first removed, and the gear 260 and the auxiliary plate 451a are sequentially separated.

As described above, in the present invention, it is possible to construct the pulling unit in a prefabricated manner, which facilitates the manufacture of the adjusting device, reduces cost, and further maintains the tension of the reinforcing wire with one pulling unit.

Meanwhile, the locking member 402 may be assembled in a way that is fitted from the front to the inside as well as a method of sliding left and right as shown in FIG. 3, and is selectively assembled before or after so that the second adjustment part is fitted.

Protective plate (500)

The protection plate 500 according to the present invention includes a corner protection plate 520 and a front protection plate 540. These protective plates are assembled by being fitted into the grooves 222 formed in the reinforcing plate 220, and the brackets, adjusting devices, and reinforcing wires protruding by reinforcing the columns are prevented from colliding or scratching by a vehicle or a person.

This protective plate may be composed of a synthetic resin or rubber plate, preferably in the form of a screen, and may be used as a picture, text or billboard.

Filling material (600)

The filler 600 according to the present invention is filled between the protection plate and the pillar, and protects the person or vehicle colliding with the pillar and the pillar by buffering the impact, and further reinforces the pillar and wraps around the reinforcing wire to maintain a tension state. To be able to do it.

The filler according to the present invention is a mixture of urethane, a curing agent, and water. Urethane is preferably a foamable urethane, which is injected between the protective plate 500 and the pillar to foam and cure.

These fillers are configured to spray using a storage tank in which urethane, hardener, and water are stored, respectively, a mixing tank for mixing urethane, hardener, and water transferred from these tanks, and a gun-type spraying device connected to the mixing tank.

In the drawings, reference numeral 700 denotes a buffer plate.

This buffer plate is interposed between the bracket and the pillar to buffer the impact, and is composed of a rubber plate or the like.

In addition, the present invention can be constructed on a circular column as well as a square column as shown in the drawings.

The following describes a column reinforcement method using the present invention made of such a configuration.

The column reinforcement method according to the present invention begins by first grinding the outer wall of the column by grinding, and then attaching the bracket 200 by applying an adhesive to the surface.

Of course, it is also possible to provide a buffer plate 700 between them, if necessary.

The bracket having a flat sectional shape of "a" has a configuration in which a hole is drilled in each of the reinforcing plate and the fixing plate, and an anchor 120 is installed in the anchor hole 212 formed in the fixing plate to be fixed to the column, and the hole of the reinforcing plate ( A reinforcing wire 300 is fitted to 222.

The reinforcing wire is fitted in a direction in which the first wire 320 and the second wire 340 face each other, and a threaded portion is provided in each to adjust the length, and the first and second adjusting parts 420 and 440 are fitted. .

Meanwhile, when a pulling part is assembled to the first adjusting part 420, and when the second adjusting part 440 is inserted into the first adjusting part, the magnet is connected by pulling the second adjusting part, and at this time, a stepped surface having a unidirectional protrusion It is a structure that is fitted between the upper and lower gears of this pulling part.

In this state, the operator inserts the fixing pin to completely connect the first control unit and the second control unit, and rotates one of the gears of the pulling unit so that the reinforcing wire is pulled tightly.

When the reinforcing wire is pulled taut, a stiffening pin is inserted to prevent the second wire from moving, and a protective plate is assembled to the bracket.

The protective plate is installed at the corners or the entire column as necessary, and the filler is foamed to completely reinforce the column.

As described above, those skilled in the art to which the present invention pertains will be able to understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features. Therefore, all the embodiments described above are illustrative and should be understood as non-limiting. The scope of the present invention should be construed as including all changes or modified forms derived from the meaning and scope of the claims to be described later rather than the above detailed description, and equivalent concepts thereof.

10: pillar 100: reinforcement device
200: bracket 300: reinforcement wire
400: control device 500: protective plate

Claims (5)

This is a construction method that reinforces the splint of a building structure to withstand vibration and earthquakes.
Grinding the outer wall of the column by grinding and applying an adhesive to the surface; A column reinforcement preparation step in which holes are formed at equal intervals in the reinforcing plate of the bracket having a flat cross-section of "a" shape, and the adjacent fixing plate is adhered to the adhesive, and is installed symmetrically around each corner of the column; A bracket fixing step of drilling an anchor hole in the bracket and the column, and driving and fixing an anchor in the anchor hole;
As a reinforcing wire construction step of reinforcing the post by inserting a reinforcing wire into the holes of the bracket installed at each end of one side of the post,
A wire rod fitting step of inserting the first wire rod into the hole of the one side bracket and inserting the second wire rod into the hole of the other side bracket;
An installation step of installing a pulling unit consisting of upper and lower gears into the first adjustment unit into which the first wire is inserted; And
An assembling step of inserting the screw part of the first wire into the first adjusting part and then assembling by fastening the nut, and assembling the second wire by inserting the stepped surface on which the unidirectional protrusion is formed into the second adjusting part;
The second adjusting part is inserted into the first adjusting part, and a magnet provided in the first adjusting part pulls and connects the second adjusting part with magnetic force, and the stepped surface of the second wire inserted in the second adjusting part is connected to the first adjusting part. A primary connection step fitted between the installed upper and lower gears;
After the first connection, an inspection step of checking the number, position and spacing of reinforcing wires; And a binding step of pressing the fixing pin provided in the first adjusting part to bind the first adjusting part and the second adjusting part.
A tension adjusting step of pulling the reinforcing wire in tension by rotating a rotation shaft of one of the gears of the pulling unit;
A protective plate installation step of enclosing the brackets disposed on both sides of the pillar with a protective plate to protect the bracket from external shocks and protruding from the corners to protect pedestrians or vehicles when they collide;
Including; a filling step of filling a filler mixed with urethane, a curing agent, and water into the protective plate,
In the step of installing the pulling part, butt the upper and lower gears on the inner surface of the auxiliary plate, insert the rotation shaft into each gear, and then assemble the auxiliary plate to the bottom of the first adjustment unit, and push the rotation shaft again to bind installed on the wall of the first adjustment unit. Column shear strength reinforcement method comprising inserting into a shaft hole of a plate. delete It is a reinforcing device that can withstand vibration and earthquakes by reinforcing the trunk of a building structure.
"ㄱ" shaped bracket installed symmetrically around the corner of the column;
A reinforcing wire composed of a first wire and a second wire that are fitted from the outside to the center of the column to each of the barckets installed on both sides of one side of the column;
An adjusting device comprising a first adjusting part fitted in the first wire and a second adjusting part fitted in the second wire, and having a magnet provided in the first adjusting part so as to be connected by pulling the second adjusting part fitted thereto by magnetic force;
It is installed in the first control unit, the gear provided on the upper and lower surfaces of the second wire rotates and pulls the second wire; includes,
The pulling unit butts the upper and lower gears on the inner surface of the auxiliary plate, and after inserting the rotation shaft into each gear, assembles the auxiliary plate to the bottom of the first adjustment unit, and pushes the rotation shaft again, the shaft hole of the binding plate installed on the wall of the first adjustment unit It is possible to assemble and disassemble with a configuration that is inserted into the
A pin hole is formed in each of the auxiliary plate and the binding plate, and a locking pin is inserted into the pin hole to prevent movement of the second wire. The method of claim 3, wherein the first wire has a head on one side and a screw for length adjustment on an opposite side, and the second wire is provided with a thread for length adjustment on one side and an inclined surface and a vertical surface on the opposite side. Pillar shear strength reinforcing device comprising a one-way protrusion formed and configured to be easily inserted when inserted into the second adjustment unit, but not fall out in the opposite direction. 4. The device of claim 3, wherein the bracket is assembled with a protection plate in which the pillar covers the corners and the front surface, and a filler mixed with urethane and a hardener is filled into the protection plate.

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