KR20090126431A - Expansion typic anchor bolt - Google Patents

Abstract

PURPOSE: An extension anchor bolt can prevent breakage or cut-off of the extension part when a bolt is inserted therein because the thickness of the extension part is uniform. CONSTITUTION: An extension anchor bolt(1) comprises a tubular body(3), an expansion part(5), and a bolt(7). The tubular body comprises a longitudinal hollow and a diameter reduction portion on the leading end of the hollow. The extension part is formed on the tip of the tubular body to be connected to the hollow, and has a longitudinally cut portion. The bolt is inserted into the hollow of the tubular body, and contacts the diameter reduction portion and extends the extension part. A holding part(13) is formed on the outer surface of the tubular body.

Description

Expandable Anchor Bolts {EXPANSION TYPIC ANCHOR BOLT}

The present invention relates to an expandable anchor bolt.

In general, anchor bolts are used to fix a building structure or steel frame to a wall or floor. Various types of such anchor bolts have been proposed, and in particular, anchor bolts are widely used.

The expandable anchor bolt is composed of a pipe body embedded into the anchor hole formed on the wall or the bottom surface, and a bolt inserted through the inside of the pipe body to extend the front end of the pipe body to the outside.

In the expandable anchor bolt having such a structure, the tubular body is manufactured by injection molding using an injection material. An extension part is provided at the tip of the tube, and the extension part is divided into two parts by an incision. In addition, the extension portion is a shape that gradually decreases the inner diameter toward the tip portion.

Therefore, when the bolt is inserted into the inside of the tubular body, the expansion part is expanded outward by the pressure of the bolt, so that the expansion part is pressed into the anchor hole.

In this case, the cutout may be formed in a straight shape, or may be formed in a slight curved shape.

In addition, the injection apparatus for manufacturing the expandable anchor bolt, the upper and lower molds filled with the injection material, the first core protruding into the upper and lower molds to form a cutout of the tubular end, and enters into the mold Thereby forming a second core which forms a space into which the bolt is inserted. At this time, since the first core has the same shape as the cutout of the tube, the first core has a straight or slightly curved shape.

Therefore, when the second core enters the inside of the front end of the first core, the outer peripheral surface of the second core proceeds to be in contact with the front end of the first core, and after the injection material filled in the mold is cured, The first and second cores are separated from the mold, and the cured injection material is separated from the mold, so that a hollow body can be manufactured.

However, in the expansion anchor bolt, when the second core advances into and out of the mold in the injection process, the first core is linearly or slightly curved, so that a specific portion of the second core intensively contacts the tip of the first core. There is a problem that can cause serious wear.

As a result, a gap occurs between the first core and the second core due to such uneven wear, and when the injection material is introduced into the gap during injection, the injected tubular body may have a variation in the thickness of the expanded portion or the surface becomes rough.

In addition, there is a problem that the thickness deviation occurs in the expansion portion of the tube, the bolt is also eccentrically inserted when the bolt is inserted, so that the thin portion is ruptured or broken, so that the tightening or fixing force of the anchor bolt may be lowered.

In addition, since the cutout formed in the extension part has a straight shape or a slight curved shape, when a tension force is applied to the anchor bolt while the extension part is pressed against the inner surface of the anchor hole, the portion where the frictional force does not act is linear or curved. There is a problem that can be reduced by fixing the anchor bolt to the concentration.

Accordingly, an object of the present invention is to solve the conventional problems as described above, the present invention is to expand the anchor portion of the tube by forming a uniform thickness of the expansion portion that can prevent the specific portion of the expansion portion to rupture or disconnection The purpose is to provide a bolt.

In addition, in the case of injection of the tubular body, the second core is located in the center of the mold and enters into the mold, thereby making the extension anchor bolt capable of extending the life of the mold by uniformly contacting the second core and the first core to prevent uneven wear. The purpose is to provide a device.

In order to achieve the object as described above, preferred embodiments of the present invention

A hollow is formed in the longitudinal direction, the tube body is formed in the diameter reduction portion inside the hollow; It is provided at one end of the tube and flows with the hollow, the incision is formed in the longitudinal direction, the amplitude of the incision is less than 1/2 of the inner diameter of the hollow, longer than 1/4 of the inner diameter of the hollow Having an extension; And a bolt inserted into the hollow of the tubular body and contacting the diameter reducing part to expand the expansion part to the outside.

Expanded anchor bolt according to the present invention can be fixed by a larger friction force because the friction is generated in an oblique direction against the external force to tension the anchor bolt when the expansion portion is compressed in the anchor hole by forming a cut portion having a predetermined curvature in the expansion portion There is an advantage.

In addition, since the thickness of the expanded portion of the tube is uniformly formed, there is an advantage of preventing a specific portion from being disconnected or broken when the bolt is inserted.

In addition, during the injection process of the tubular body, injection is performed by retreating into and out of the mold while the second core is located at the center of the mold, thereby uniformly contacting the second core and the first core to prevent uneven wear, thereby extending the life of the mold. There is an advantage to extend.

Hereinafter, with reference to the accompanying drawings will be described in detail the structure of the expandable anchor bolt according to an embodiment of the present invention.

As shown in Figures 1 to 3, the expansion anchor bolt (1) proposed by the present invention is a tube (3) inserted into the anchor hole (h) formed in the wall or bottom (C; Fig. 8) And an expansion part 5 provided at the front end of the tubular body 3 and expandable to the outside, and inserted into the tubular body 3 to expand the tubular portion 5 to the outside to anchor the anchor hole h (Fig. 8). And a bolt 7 pressed against it.

In the expandable anchor bolt having such a structure, the tubular body (3) is formed inside the hollow (9) in the longitudinal direction, and injected into an injection material such as resin.

In addition, a diameter reducing part 11 is formed inside the hollow 9. This diameter reduction part 11 has a wedge shape, and the inner diameter thereof becomes smaller toward the distal end of the tube 3.

Therefore, when the said bolt 7 is inserted in the inside of the tubular body 3, the front-end | tip part of the bolt 7 can contact this diameter reduction part 11, and can expand and press the expansion part 5 to the outside. .

In addition, since the engaging portion 13 is formed on the outer circumferential surface of the tubular body 3, the frictional force with the anchor hole h (Fig. 8) can be increased.

That is, the locking portion 13 includes an inclined surface 15 formed in the front end direction of the tubular body 3 and a locking jaw 17 formed in the proximal direction of the inclined surface 15.

Therefore, when the tube 3 is inserted into the anchor hole h, the inclined surface 15 is in sliding contact with the inner circumferential surface of the anchor hole h, so that the tube 3 can be smoothly inserted.

On the other hand, in the opposite direction, the engaging jaw 17 is in non-slip contact with the inner circumferential surface of the anchor hole h, thereby preventing the external drawing of the tubular body 3 due to the tension of the bolt 7.

On the other hand, the expansion portion 5 is provided at the front end of the tubular body 3, it can be expanded to the outside by the bolt (7) inserted through the hollow 9 can be pressed on the inner surface of the anchor hole (h). .

In the extension part 5, a pair of cutouts S and S1 having a predetermined curvature are formed in the longitudinal direction. Then, the expansion part 5 is separated into the first and second expansion members 20 and 22 by the cutouts S and S1.

Therefore, when the front end of the bolt 7 is inserted into the tubular body 3 to reach the expansion part 5, the first and second expansion members 20 and 22 extend outwardly to anchor holes h. It can be pressed on the inner side of the.

In addition, the cutouts S and S1 are waveform curves in which a curve having a predetermined curvature is continuously formed, and extension grooves S3 and S5 are formed in upper and lower portions thereof.

The amplitude (a) of the cutouts (S, S1) is defined as the amplitude (a) of the displacement in the left and right directions about the longitudinal centerline of the tubular body 3, and can be determined by the following equation.

     D / 4 <a <D / 2 ----------- Equation 1 (D: Bore size, a: Incision amplitude)

That is, the amplitude (a) of the cutouts (S, S1) is less than half of the inner diameter (D) of the hollow (9), longer than 1/4 of the inner diameter (D) of the hollow (9) Has

As such, since the cutouts S and S1 are waveforms having a amplitude (a) in a predetermined range, when the cutouts S and S1 enter and expand inside the anchor hole h, the cutouts S and S1 may be efficiently compressed to the inner circumferential surface of the anchor hole h. Can be.

That is, as shown in FIGS. 2 and 3, in the first position AA, the cutout portion S is positioned at the middle portion h1 of the expansion portion 5, and in the second position BB, the cutout portion ( S is in contact with one side h2 of the extension 5, and in the third position CC, the cutout S is in contact with the other side h3 of the extension 5.

Therefore, when the expansion part 5 is expanded and compressed inside the anchor hole h, the cutouts S and S1 to which the frictional force does not act have an amplitude a of a predetermined range or more, so that the first and the first 2 By spreading the friction area between the expansion members 20 and 22 and the inner side of the anchor hole h, the friction force can be increased to be uniform.

The relationship between the amplitude a of the cutouts S and S1 and the frictional force will be described with reference to FIGS. 4A and 4B.

That is, Figure 4 (a) is shown in the unfolded expanded portion formed in the cut portion according to the present invention, Figure 4 (b) shows a case in which a straight groove or a slightly cut portion is formed in the expansion portion.

In the expanded portion shown in FIG. 4 (a), the cutouts S and S1 have a constant amplitude a so that the first and second expandable members 20 and 22 to which the frictional force acts have the cutouts S, Since the friction force is generated in an oblique direction with respect to the external force in the direction of the arrow to tension the anchor bolt 1 because it is formed along S1) it can generate a greater friction force.

On the other hand, in the case of Fig. 4 (b), since the groove S2 is straight or slightly curved, the portion where no friction force is applied is concentrated on the straight portion, so that the friction force is in a straight direction against the external force to tension the anchor bolt 1. As a result, a smaller friction force than the cutouts S and S1 of FIG.

As a result, by implementing the groove shape of the extension part 5 in the shape of cutouts S and S1 having a predetermined curvature, it is possible to prevent the lowering of the fixing force as compared with the case of the straight or slight curve.

Referring again to FIGS. 1 to 3, in the above definition of the shape of the cutouts S and S1, the amplitude a is defined as a variable, but the present invention is not limited thereto. The width L of S1) may be defined within the range of 1/10 to 3/10 of the inner diameter D of the hollow 9.

As such, when the width L of the cutouts S and S1 is set within the range as described above, the expansion part 5 may be pressed against the inner circumferential surface of the anchor hole h by a larger friction force.

In addition, the first and second extension grooves S3 and S5 are further formed at upper and lower portions of the cutouts S and S1, so that the cutouts S and S1 are extended when the extension part 5 is extended outward. Since the width of the first and second extension grooves (S3, S5) is a reference line so that the incision (S, S1) can be uniformly expanded.

Although the shape of the cutouts S and S1 has been described above as a curve, the present invention is not limited thereto and may be variously modified.

That is, the cutouts S and S1 may be formed in a coil shape by winding along the longitudinal direction on the extension part 5.

Alternatively, the cutouts S and S1 may be formed not only as a curved shape of one cycle, but also as a two-cycle curve by repeating the curve of one cycle once more as shown in FIG. 4 (a). .

On the other hand, the manufacturing method of the expansion anchor bolt according to the present invention will be described with reference to FIGS.

As shown, the manufacturing method of the expandable anchor bolt according to the present invention comprises the steps of assembling the mold 30 (S100), filling the injection material in the mold 30 (S110), and the second core In step S120, a hollow 9 is formed and hardened by entering 36 into the mold 30.

In the method of manufacturing an expandable anchor bolt made of such a step, in the mold assembly step (S100) to assemble a mold (hereinafter, an expanded anchor bolt manufacturing device; 30) for manufacturing the expandable anchor bolt (1).

The expanded anchor bolt manufacturing apparatus 1 is an outer mold 32 filled with the injection material, and protrudes to the inside of the outer mold 32 to form cutouts (S, S1) of the expansion portion (5; Figure 2) A first core 34 and a second core 36 is formed into the outer mold 32 to form a space 36 into which the bolt 7 is inserted.

In the expanded anchor bolt manufacturing apparatus having such a structure, the outer mold 32 is composed of the upper mold 38 and the lower mold 40, the predetermined space 36 is formed therein, the injection material is filled to the tubular body (3) can be injected.

The first core 34 protrudes radially inward from the upper and lower molds 38 and 40, respectively. At this time, the first core 34 has the same shape as the cutouts (S, S1) of the expandable anchor bolt 1, the injection core is not filled in the space occupied by the first core 34 during injection , Cutouts S and S1 of the extension part 5 may be formed.

In addition, the first core 34 has the same shape as a waveform curve having a constant curvature, that is, the cutouts S and S1 of the extension 5.

The waveform of the first core 34 is defined as the amplitude (a) in the left and right directions about the longitudinal center axis, as in the case of the cutouts (S, S1), and can be determined by the following equation. have.

     D / 4 <a <D / 2 ----------- Equation 2 (D: inner diameter of the tube, a: amplitude of the first core)

That is, the amplitude (a) of the first core 34 is less than 1/2 of the inner diameter (D) of the hollow (9), and longer than 1/4 of the inner diameter (D) of the hollow (9) Have

As described above, the first core 34 having the amplitude (a) of a predetermined range or more may protrude into the outer mold 32.

In this state, the injection material filling step S110 is performed. That is, the injection molding material is injected and filled in a state in which the first core 34 having a waveform curve of a predetermined curvature protrudes inside the outer mold 32.

In this case, since the injection material is not filled in the space occupied by the first core 34, the cutouts S and S1 as described above may be formed.

As such, after the injection molding step S110 is completed, the step S120 of entering the second core 36 into the outer mold 32 is performed.

When the second core 36 enters the inside of the outer mold 32, the outer surface 48 of the second core 36 comes into contact with the inner surface 50 of the first core 34, and the outside Since the injection material filled in the mold 32 is discharged to the outside by the second core 36, the tubular body 3 on which the hollow 9 is formed may be molded.

At this time, since the first core 34 is a waveform having a predetermined amplitude (a), the outer surface of the second core 36 entering the inside of the outer mold 32 can be efficiently wrapped in the circumferential direction. .

That is, as shown in FIGS. 6 and 7, in the fourth position EE, the first core 34 contacts the intermediate position 42 of the second core 36, and in the fifth position FF. The first core 34 contacts one side 44 of the second core 36, and the first core 34 contacts the other side 46 of the second core 36 in the sixth position GG. .

As a result, when the second core 36 enters the inside of the outer mold 32, the first core 34 supports the second core 36 from all directions.

Therefore, since the second core 36 enters the inside of the outer mold 32 in a state in which the second core 36 is uniformly supported by the first core 34 having a predetermined range of amplitude a, the second core 36 is eccentric to a specific position. Can be prevented.

In addition, since the second core 36 enters the inside of the outer mold 32 in a state in which the second core 36 is located at the center, the second core 36 and the first core 34 are in uniform contact with each other. Uneven wear of the 34 and the second core 36 may be minimized.

Therefore, the gap of the outer mold 32 due to uneven wear can be prevented, so that the thickness of the injected tubular body 3 is constant and the surface can be formed smoothly.

In addition, since the thickness of the extension part 5 of the tubular body 3 is uniformly formed, when the bolt 7 is inserted into the tubular body 3, the bolt part may be inserted in the center of the tubular body 3 so that the thin portion is ruptured or disconnected. Can be prevented.

Although the shape of the first core 34 has been described above as a curve, the present invention is not limited thereto and may be variously modified.

That is, the first core 34 may be formed in a coil shape by winding along the longitudinal direction inside the outer mold 32.

Alternatively, as illustrated in FIG. 6, the first core 34 may be formed not only in the curved shape of one cycle but also in a two-cycle curve by repeating one cycle of the curve one more time.

On the other hand, the construction process of the expandable anchor bolt according to the present invention will be described in more detail with reference to Figs.

As shown, when constructing the expansion anchor bolt 1, to form an anchor hole (h) in the wall or bottom (C). Then, the tubular body 3 is inserted into the anchor hole h by pressing or hitting.

At this time, since the engaging portion 13 is formed on the outer circumferential surface of the tubular body 3, when the tubular body 3 is inserted into the anchor hole h, the inclined surface 15 comes into contact with the anchor hole h. In this case, if the smoothing and withdrawal, the catching jaw 17 is in contact, so the withdrawal can be suppressed.

In this way, after inserting the tubular body 3 into the anchor hole h, the bolt 7 is inserted into the hollow 9 of the tubular body 3.

When the bolt 7 is inserted into the tubular body 3, the extension part 5 expands to the outside as the tip of the bolt 7 contacts the diameter reducing part 11 formed at the tip of the hollow 9. The locking portion 13 may be pressed onto the inner circumferential surface of the anchor hole h.

In this case, since the cutouts S and S1 of the expansion part 5 are waveform curves within a predetermined curvature range, the portion where the friction force does not work is distributed along the waveform, thereby preventing a decrease in the fixing force of the expansion anchor bolt 1. have.

As described above, the expansion anchor bolt according to the present invention is bolted to the hollow 9 of the tubular body 3 as the first and second expansion members 20 and 22 are uniformly molded without being eccentric in the injection process. In the case of inserting (7), the tip of the bolt (7) is in uniform contact with the inner wall of the hollow (9) to prevent the tip of the bolt (7) from being eccentric to the inner portion of the extension portion 5 to rupture Can be.

1 is a front view showing the appearance of the expandable anchor bolt according to the present invention.

FIG. 2 is a partially enlarged cross-sectional view showing an enlarged portion of FIG. 1.

3 is a cross-sectional view of "A-A", "B-B", and "C-C" of FIG.

Figure 4 (a) is an exploded view of the expanded portion formed in accordance with the present invention, Figure 4 (b) is an exploded view of the existing expanded portion formed.

5 is a flowchart illustrating a method of manufacturing an expandable anchor bolt according to the present invention.

Figure 6 is a cross-sectional view schematically showing the structure of an expanded anchor bolt manufacturing apparatus according to the present invention.

FIG. 7 is a cross-sectional view of "E-E", "F-F", and "G-G" of FIG. 6.

8 is a view illustrating a state in which the expandable anchor bolt shown in FIG.

Claims (7)

A hollow body is formed in the longitudinal direction, the tube body is formed in the diameter reduction portion inside the front end of the hollow; It is provided at the front end of the tubular body and flows with the hollow, the incision is formed in the longitudinal direction, the amplitude of the incision is less than 1/2 of the inner diameter of the hollow, having a length longer than 1/4 of the inner diameter of the hollow An extension; And An expansion anchor bolt including a bolt inserted into the hollow of the tubular to extend the expansion portion to the outside by contacting the diameter reducing portion. The method of claim 1, Expanded anchor bolt, characterized in that the width of the incision is within the range of 1/10 to 3/10 of the inner diameter of the hollow. The method of claim 1, The expansion part expansion anchor bolt further comprises a first and second extension grooves in the upper and lower portions of the incision. In the method of manufacturing an expandable anchor bolt consisting of a hollow body and the expansion portion is connected to the front end of the tube, the incision is formed, An outer mold, a first core projecting inwardly of the outer mold, the first core having an amplitude less than one-half the inner diameter of the tubular body and having a length longer than one-fourth the inner diameter, and accessible into the outer mold; Assembling a mold comprising a second core; Filling an injection material into the mold; And Expanding anchor bolt manufacturing method comprising the step of forming a hollow in the tube by entering the second core into the mold, and hardening. The method of claim 4, wherein The width of the first core is an expanded anchor bolt manufacturing method, characterized in that within the range of 1/10 to 3/10 of the inner diameter of the hollow. External mold is filled with the injection material to inject the tube; A first core projecting inwardly of the outer mold and having a length less than one-half the inner diameter of the tube and longer than one-fourth the inner diameter; And Expanded anchor bolt manufacturing apparatus comprising a second core to form a hollow in which the bolt is inserted by discharging the injection material filled by entering the inside of the outer mold. The method of claim 6, Expanded anchor bolt manufacturing apparatus, characterized in that the width of the first core is within the range of 1/10 to 3/10 of the inner diameter of the hollow.

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