JPH1018510A - Threaded bar joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To join together threaded bars easily and surely by threadedly fitting a first coupler having external thread to one threaded bar and a second coupler having a step part to the other threaded bar, and joining the couplers with each other through a collar. SOLUTION: A first coupler 2 having threaded parts 2a, 2b on the inner face and the outer face is threadedly fitted to the end part of one threaded bar 5, and a second coupler 3 having a threaded part 3a on the inner face and a step part 3b on the outer face is threadedly fitted to the end part of the other threaded bar 6. Next, the the first coupler 2 and the second coupler 3 are joined together so that the lock part 4b of a collar 4 is locked with the step part 3b of the second coupler, the internal thread 4a of the collar is threadedly engaged with the external thread 2b of the first coupler, and the collar 4 is rotated. After joning together, grout is injected from an injection hole 7 and hardened. These joints 2, 3, 4 are formed out of nodular graphite cast iron in state of cast surface. It is constituted so that even the threaded bars 5, 6 of different pitch can be easily joined together. Hereby, the joint of high strength can be provided at a low price.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rebar joint for connecting deformed rebars, such as screw rebars, in civil engineering construction or the like.

[0002]

2. Description of the Related Art Conventionally, a large number of reinforcing bars have been used for the construction of concrete structures and trusses for civil engineering and construction work, but the reinforcing bars used in such works are fixed to concrete. The use of screw rebars, which are easy to join and easy to join, has increased. In addition, various methods of connection, such as welding and mechanical joints using couplers, have been developed, and use of mechanical joints that can shorten the construction period without using fire, especially without being affected by the weather such as wind and rain. Has spread and has been put to practical use.

For example, Japanese Unexamined Patent Publication No. Hei 6-288040 discloses a "bar steel joint fitting" in which a joint which can be joined even when there is a phase difference between the screws of the bar steels to be joined is constituted by two couplers. ing. As shown in FIG. 6, this “bar joint fitting” is composed of the “first coupler 31 and the second coupler 31.
A female screw 31a is formed on the inner surface of the first coupler 31 to be screwed into the male screw 33a of the steel bar 33 to be joined, and the male screw 33 of the steel bar 33 is formed on the outer surface.
male screw portion 31b of the pitch P ₁ is smaller than the pitch P ₂ of a is formed. The first coupler 32 is screwed into the male screw 34a of the other steel bar 34 to be joined to the inner surface of the second coupler 32.
A female screw part 32a and a second female screw part 32b screwed to the male screw part 31b on the outer surface of the first coupler 31 are formed in two stages. Is the thing.

[0004] A method of joining steel bars by using a "bar joint fitting" disclosed in Japanese Patent Application Laid-Open No. 6-288040 is described as follows: "First, the male thread portion 31b of the first coupler 31 is attached to the second female thread portion 32b of the second coupler 32. Is screwed into the female screw portion 31a of the first coupler 31 with the male screw 33a of one bar steel 33 to be joined, and then the male screw 34a of the other steel bar 34 to be joined and the second thread of the second coupler 32. The phase difference θ ₀ with the first female screw portion 32 a is
And rotation of the second coupler 32 and the second coupler 32
Adjustment is made to be substantially 0 (zero) by a combination with only rotation. In this state, the first female screw portion 32a of the second coupler 32 is turned into the male screw 34a of the other steel bar 34 by integrally rotating the first coupler 31 and the second coupler 32.
, The pair of steel bars 33 and 34 are joined. Further, a pair of steel bars 33 joined in this manner,
In order to fix the first coupler 31 and the second coupler 32, the first coupler 31 and the second coupler 32 may be rotated by applying necessary torque in opposite directions, or the first coupler 31 and the second coupler 31 For example, there is a method of injecting a grout material into a fitting fitting made of 32 and hardening the grout material. ]. Reference numerals 35 and 36 denote spanner hooks.

Further, Japanese Utility Model Laid-Open No. 3-18313 discloses that
There is disclosed a "rebar joint" that can be easily connected even if the screw pitch of both screw rebars to be connected is shifted. As shown in FIG. 7 (a cross-sectional view of a state where the reinforcing bars are connected to each other), the “rebar joint” includes a “short tubular joint body 53 and a cap (engagement) attached to the tip of the screw reinforcing bar 51B. ), A stopper (screw member) 55 that is screwed into the joint main body 53, and lock nuts 56 and 57.
Reference numeral 51B denotes a reinforcing bar extending from the reinforced concrete units A and B to be connected, and a spiral convex portion 52 having the same shape and the same pitch is provided on the outer peripheral surface thereof. "
It is assumed that.

As shown in FIG. 8, the connecting procedure of the threaded rebars 51A and 51B by the "rebar joint" disclosed in Japanese Utility Model Laid-Open Publication No. 3-18313 is as follows. The main body 53 is screwed in so that the tip of the screw reinforcing bar 51A is screwed into the screw hole 53 of the joint main body 53.
Position it so that it is exposed from c. At the same time, the lock nut 57 is screwed into the screw reinforcing bar 51B, the stopper 55 is inserted, and the cap 54 is further screwed and fixed to the tip of the screw reinforcing bar 51B. In addition, cap 5
4 and the stopper 55 are separated by a predetermined dimension. And
Concrete units A and B are opposed to each other by setting a predetermined distance between the tip of the screw reinforcing bar 51A and the tip of the cap 54. Next, the joint body 53 is turned to
It moves to the B side, and the tip of the screw rebar 51B, together with the cap 54, enters the screw hole 53c and the straight hole 53b of the joint body 53. Then, when the tip of the screw reinforcing bar 51A is located substantially at the boundary between the screw hole 53a of the joint body 53 and the straight hole 53b, the cylindrical portion 5 of the stopper 55
The male screw 5b is screwed into the screw hole 53c of the joint main body 53, and the tip of the stopper 55 is brought into contact with the rear end of the cap 54 to engage. As a result, the reinforcing bar 51B does not come off from the joint main body 53. Thereafter, the lock nuts 56 and 57 are tightened. Further, mortar is injected from the grout injection port 53d of the joint main body 53 to fill a gap in the joint main body 53 and solidify the mortar, so that the screw rebar 51B is fixed to the joint main body 53. As a result, the double screw rebar 51A , 51B are firmly connected. ].

[0007]

Conventionally, in the connection of threaded rebars, it takes time and effort to adjust the deviation and position of the screw pitch of the threaded rebar by means of fittings and the like. There was a problem that appearance was bad.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to eliminate the need for any adjustment of the screw pitch of the screw rebar, and to facilitate the adjustment regardless of the position of the screw pitch. It can be easily combined and tightened,
An object of the present invention is to provide a threaded steel joint with reduced weight that does not require machining of a screw portion and is made of a casting.

The inventor of the present invention has conducted intensive studies on the structure and material of the threaded rebar joint in order to achieve the above-mentioned object. As a result, the threaded rebar joint has a structure which is not affected at all by the deviation of the thread pitch of the threaded rebar or its position. In addition, in order to end the processing of the threaded part and withstand large loads, the threaded part is made of casting surface, and the spheroidal graphite cast iron with good fluidity is used, and its high strength is further improved. When necessary, the present invention was conceived of using austempered spheroidal graphite cast iron, and made the present invention. The “casting skin” in the present invention means a casting skin in an as-cast state of a casting, which means a surface skin of a casting that has not been machined.

[0010]

That is, in the threaded bar joint of the present invention, a female threaded portion is formed on the inner surface to be screwed into a male thread of the threaded bar on one side to be joined, and the outer surface of the collar is formed on the outer surface. A first coupler formed with a male screw portion to be screwed to the female screw portion, and a female screw portion to be screwed into the male screw of the screw reinforcing bar on the other side to be joined are formed on the inner surface, and a collar is formed on the outer surface. A second coupler having a stepped portion for locking with the inner surface of the locking portion of the locking portion; and a second coupler disposed on the outer periphery of the first coupler and the second coupler, and having an inner surface on one side. The female screw portion is formed, and the collar on the other end is formed with the collar.

[0011] In the threaded bar joint of the present invention, a female thread portion to be screwed into the male thread of the threaded bar on one side to be joined is formed on the inner surface with a casting surface, and one side of the collar is formed on the outer surface. A first coupler of an iron-based casting formed with a casting skin on the inner surface of which has a male screw portion screwed with a female screw portion formed with a casting skin, and a male screw of a screw reinforcing bar on the other side to be joined on the inner surface. A female screw portion to be screwed into the collar is formed by casting skin, and a stepped portion is formed on the outer surface of the collar on the other end of the collar to be engaged with an inner surface of a locking portion formed in an inner surface direction. A second coupler made of iron-based casting, and the female screw portion formed on the outer surface of the first coupler and the second coupler and formed on the inner surface on one side with a casting surface. At the same time, the locking portion is formed at the other end, and a collar of an iron-based casting whose outer surface is formed in a polygonal shape Characterized in that it comprises more.

[0012] In addition, the threaded steel joint of the present invention is characterized in that the first coupler screwed into the male thread of the threaded bar on one side and the second coupler screwed into the male thread of the threaded bar on the other side. The coupling means is connected to the outer surface of the second coupler by screwing the female screw portion formed on the inner surface on one side of the collar and the male screw portion formed on the outer surface of the first coupler. The locking is performed by locking the formed stepped portion and the locking portion inner surface of the locking portion formed at the end of the collar.

Further, in the threaded rebar joint according to the present invention, a straight portion formed from the base of the inner surface of the locking portion of the collar to be larger in diameter than the outer diameter of the second coupler and to have the same inner diameter, It is formed on the inner surface on one side and extends to the end of the female screw portion extending on the other side.

[0014] Further, the threaded rebar joint according to the present invention is characterized in that:
A ring-shaped gap is formed between the outer peripheral surface of the coupler and the inner peripheral surface of the collar. Further, a grout material injection hole penetrating from the outer surface to the inner surface of the collar is formed.

[0015] Further, the threaded rebar joint of the present invention is characterized in that:
Each of the coupler, the second coupler, and the collar is made of spheroidal graphite cast iron. Alternatively, the material of the first coupler, the second coupler, and the collar is austempered spheroidal graphite cast iron.

By manufacturing the threaded joint of the present invention by casting, the hole of the threaded portion can be easily formed by using a core or a vanishing model. By providing a shape corresponding to the screw portion on the surface, the screw portion can be easily cast with the casting surface. If a coating mold containing alumina, zircon powder, or the like is applied to the surface of the core having the screw shape, or if the shell sand core is used for casting, a better screw surface shape of the casting surface can be obtained. . In the screw rebar joint of the present invention, the shape of the screw portion is not formed by machining, so that the manufacturing cost is low.

The material of the components of the threaded bar joint of the present invention may be a steel-based casting, which is an iron-based casting. However, the casting iron-based casting has a lower melting temperature than the steel-based casting, and particularly has a good flowability. Therefore, it is easy to obtain a clean casting surface with good dimensional accuracy, and it is particularly suitable for a member in which the thread portion is formed by the casting surface, and spheroidal graphite cast iron is desirable.

The threaded bar joint of the present invention is made of FCD material (spheroidal graphite cast iron). As the FCD material, JIS FCD450 or FCD500, which is a general material, is used. Its tensile strength and proof stress are comparable to those of ordinary steel castings, and it is easy to manufacture. If higher tensile strength and proof stress are required, JIS FCD600 to FCD700 or FCD80
It may be set to 0. The tensile strength is comparable to the quenched / tempered material of steel castings, and it is possible to reduce the size and weight of the threaded steel joint. If further wear resistance or the like is required for the screw portion or the like, the material can be improved by quenching / tempering the whole or a part of the FCD material.

Further, when even higher strength is required, the material is austempered spheroidal graphite cast iron. This material is obtained by subjecting spheroidal graphite cast iron to an austempering treatment, and setting the austenitizing temperature at 800 to 950 ° C.
After quenching to 200-400 ° C after holding for ~ 5 hours, cooling for 0.5 hours or more and cooling with water or air, etc.
It is possible to select the strength from S · FCD900A to FCD1200A. Tensile strength is JIS FCD450
2 to 3 times as strong as the above, and further downsizing and weight reduction are possible. It goes without saying that the threaded steel rebar joint of the present invention manufactured in this way can be adopted as a joint in general machines and devices by casting by changing the shape and pitch of the screw. In addition, since the screw portion is manufactured using a casting, the screw portion can be easily machined after the screw portion is manufactured using a core or a disappearing model.

[0020]

FIG. 1 is a block diagram showing an embodiment of the present invention.
5 will be described in detail, but the present invention is not limited to these.

[0021]

Embodiment 1 FIGS. 1 to 5 show an embodiment of the present invention. FIG. 1 shows the overall configuration of the threaded steel joint of the present invention,
It is sectional drawing which shows the state which combined screw rebar by the screw rebar joint. FIG. 2 is a partial cross-sectional view showing a state in which the screw reinforcing bar on one side is screwed into a female screw portion formed on the inner surface of the first coupler. FIG. 3 shows that the screw reinforcement on the other side is second.
It is a fragmentary sectional view showing the state where it was screwed into the female screw part formed in the inside of the coupler. FIG. 4 is a partial cross-sectional view showing a state in which a male screw portion formed on the outer surface of the first coupler and a female screw portion formed on one inner surface of the collar are screwed. FIG. 5 is a cross-sectional view showing the procedure for connecting the screw rebars.

As shown in FIG. 1, the threaded reinforcing bar joint 1 of the present invention comprises a first coupler 2, a second coupler 3, and a collar 4, and the inner surface of the first coupler 2 has one side to be joined. A female screw portion 2a to be screwed with the male screw 5a of the screw reinforcing bar 5 is formed, and one side of the collar 4 (the screw reinforcing bar 5 side) is formed on the outer surface.
Male screw part 2 screwed into female screw part 4a formed on the inner surface of
b is formed. On the inner surface of the second coupler 3, a female screw portion 3a to be screwed with the male screw 6a of the screw reinforcing bar 6 on the other side to be joined is formed. A stepped portion 3b that locks with the locking portion inner surface 4c of the locking portion 4b formed in the direction is formed. A ring-shaped gap 8 (see FIG. 4) is provided between the small outer diameter portion 3d of the second coupler 3 and the tip (minimum diameter portion) 4f (see FIG. 5) of the locking portion 4b of the collar 4. The ring-shaped gap 9 (see FIG. 4) is also formed between the large diameter portion 3e of the outer diameter of the second coupler 3 and the straight portion 4d on the inner surface of the collar 4, so that the collar 4 is Before being screwed into the first coupler 2, the collar 4 can be freely rotated around the outer peripheral surface of the second coupler 3 without any obstacle, and can be rotated in the left-right direction (axial direction). Since the movement and the obstacle are not hindered at all, the fastening operation by the collar 4 can be extremely easily and smoothly performed.

On the inner surface of the collar 4 on one side (the screw rebar 5 side), there is formed a female screw portion 4a which is screwed with a male screw portion 2b formed on the outer surface of the first coupler 2, A locking portion 4b is formed such that an end on the other side (the screw reinforcing bar 6 side) protrudes inward, and has the same inner diameter in the axial direction (on one side of the screw reinforcing bar 5) from the root of the locking portion 4b. A straight portion 4d is formed up to the end of the female screw 4a. In addition, a grout material injection hole 7 penetrates from the outer surface of the collar 4 to the inner surface of the straight portion 4d at a substantially central portion of the straight portion 4d on the inner surface of the collar 4. The shape of the outer surface 4g of the collar 4 and the end 2 on one side of the first coupler 2
The outer surface shape of c is formed in a polygonal shape so that the spanner can be easily hooked and tightened easily. Although the outer shape of the end 3c on the other side of the second coupler 3 is circular, only the end may be polygonal in consideration of tightening by a spanner. The polygon is preferably an octagon or a decagon from the viewpoint of workability.

FIG. 2 shows the male screw 5 of the screw reinforcing bar 5 on one side.
FIG. 4 is a partial cross-sectional view showing a state in which a is screwed into a female screw portion 2a formed on an inner surface of a first coupler 2. 2b is the first
It is a male screw portion formed on the outer surface of the coupler 2, and is screwed with the female screw portion 4 a of the collar 4 disposed on the outer periphery of the first coupler 2. As described above, the end 2c on one side of the first coupler 2 is formed in a polygonal shape so that the spanner can be easily hooked and tightened easily.

FIG. 3 shows the external thread 6 of the screw reinforcing bar 6 on the other side.
FIG. 6 is a partial cross-sectional view showing a state in which a is screwed into a female screw portion 3a formed on the inner surface of the second coupler 3. 3b is the second
A stepped portion formed on the outer surface (outer peripheral surface) of the coupler 3, and an inner surface 4c of the engaging portion 4b of the collar 4 disposed on the outer periphery.
To complete the connection between the screw rebars.

FIG. 4 shows a state in which the male screw 2b formed on the outer surface of the first coupler 2 and the female screw 4a formed on the inner surface on one side of the collar 4 are tightened to complete the screwing. Is shown. Ring-shaped gap portions 8 and 9 are formed on the locking portion 4 b side of the collar 4. In the gaps 8 and 9, the second coupler 3 in which the threaded reinforcing bar 6 is screwed in advance before the first coupler 2 and the collar 4 are screwed is fastened. In particular, since the ring-shaped gap portion 8 is formed, the locking portion 4b of the collar 4 is engaged before the female screw portion 4a of the collar 4 and the male screw portion 2b of the first coupler 2 are screwed.
Since the side can freely rotate and move on the 3d (small outer diameter portion) side of the second coupler 3, the work of tightening the first coupler 2 and the collar 4 can be extremely easily performed. In the tightening operation, since the outer surface 4g of the collar 4 is formed in a polygonal shape as described above, the end 4e is well hooked by the spanner, and the tightening operation can be performed extremely easily.
The ring-shaped gap 9 forms a part of a portion where the grout injected from the grout injection hole 7 is hardened.

FIG. 5 shows a procedure for connecting both screw rebars by the screw rebar joint 1 of the present invention, which will be described below. First, the screw reinforcing bar 6 is inserted into the collar 4, and the collar 4 is shifted to the left side of the screw reinforcing bar 6 in FIG.
The male screw 6 a of the screw reinforcing bar 6 is screwed into the female screw portion 3 a on the inner surface of the coupler 3. In parallel with this, the male screw 5a of the screw rebar 5 is screwed into the female screw portion 2a on the inner surface of the first coupler 2. Next, the first coupler 2 and the second coupler 3 are arranged facing each other at a predetermined distance. Then, the collar 4 is moved in the direction of the right arrow shown in FIG. 5, and the male screw portion 2 b on the outer surface of the first coupler 2 and one side of the collar 4 (the screw rebar 5
Side) is screwed with the female screw portion 4a on the inner surface of the second coupler 3, and the locking portion inner surface 4c of the locking portion 4b of the collar 4 is
b, the male screw portion 2 of the first coupler 2
The screwing of the female thread 4a of the collar 4 and the collar 4 is completed, and the connection between the screw reinforcing bars 5 and the screw reinforcing bars 6 is completed. Since the diameter of the distal end (minimum diameter portion) 4f of the locking portion 4b of the collar 4 is formed slightly larger than the outer diameter of the small diameter portion 3d of the second coupler 3, the small diameter portion 3d and the distal end are formed. (Minimum diameter part) 4f
And a small gap is formed between them, so that the small-diameter portion 3d and the tip portion (minimum-diameter portion) 4f do not interfere with contact and can be tightened without any obstacle. Since the outer shape of the collar 4 is formed in a polygonal shape, a spanner can be attached to the end 4e on the other side to perform a tightening operation. Reference numeral 7 denotes a grout material injection hole, which can be injected with a grout material and cured as needed after the connection of the two screw reinforcing bars 5 and 6 is completed.

As described above, according to the threaded joint 1 of the present invention, the two threaded reinforcing bars 5 and 6 can be easily connected to each other irrespective of the phase difference or position of the screw pitch of the threaded reinforcing bars 5 and 6. In order to connect the screw rebars 5 and 6, when the male screw 2b of the first coupler 2 and the female screw 4a formed on the inner surface of the collar 4 are screwed and tightened, the outer shape of the collar 4 is changed. Since it is formed in a polygonal shape, a spanner is easily applied to the end 4e on the other side of the collar 4, and the tightening is easy, so that the workability is good. Also, the first coupler 2
The end 2c on one side is also formed as a polygon,
If necessary, a spanner can be used for screwing the screw between the screw reinforcing bar 5 and the first coupler 2. In addition, the outer shape of the small diameter portion 3d of the second coupler 3 is circular in consideration of workability, and is a tip portion (minimum diameter portion) of the locking portion 4b of the collar 4.
Although a gap with 4f is secured, only the end of the small diameter portion 3d may be partially formed into a polygon so that a spanner can be used. For the specific shape of the polygon,
An octagon or a decagon is preferred from the viewpoint of work such as hanging of a spanner and tightening.

Since the two screw rebars thus joined are usually used by being buried in concrete, the polygon of the outer shape of the collar 4 engages with the concrete, and loosening occurs due to reverse rotation or the like. Never. However, if necessary, grouting material can be injected from the grouting material injection hole 7 of the collar 4 and cured, or the grouting material can be hardened, or the outside of the first coupler 2 (the right side of the screw reinforcing bar 5) and the second
A lock nut can be attached to the outside of the coupler 3 (left side of the screw reinforcing bar 6). Alternatively, both the grout material injection and the lock nut installation can be performed.

The first and second couplers 2 and 3 and the collar 4 of the threaded joint of the present invention having the above-described configuration.
Casting was performed using JIS FCD500 as each material. It was cast at 1420 ° C. in a sand mold. The chemical components were iron, unavoidable impurities, and the components shown in Table 1.

[0031]

[Table 1]

The test piece was cut out from the cast product and the mechanical properties were investigated. The results are shown in Table 2.

[0033]

[Table 2]

The threaded rebar joint according to the first embodiment was able to be produced without heat treatment, with a product comparable in strength to a forged product. In addition, by simply changing the material from a forged product to a spheroidal graphite cast iron with the same product shape, a weight reduction of 7% corresponding to the difference in specific gravity could be achieved.

[0035]

[Embodiment 2] The shape and configuration of the threaded steel joint were the same as those in Embodiment 1, and were cast in a sand mold at 1425 ° C. The chemical components were iron, inevitable impurities and the components shown in Table 3.

[0036]

[Table 3]

Austempering treatment was performed to obtain austempered spheroidal graphite cast iron only. That is, the cast product after solidification is taken out of the mold, and the austenitizing temperature is set at 875 ° C.
After holding for a while, the mixture was rapidly cooled at a cooling rate at which no pearlite was generated, the cooling was temporarily stopped at 385 ° C., and the mixture was gradually cooled to 345 ° C. over 2 hours, and then rapidly cooled to room temperature by water cooling. Table 4 shows the results of cutting out test pieces from the heat-treated cast products and examining their mechanical properties.

[0038]

[Table 4]

Spheroidal graphite cast iron JIS / FC of Embodiment 1
A tensile strength approximately twice as high as that of D500 was obtained, and it was possible to cope with high-strength rebars. Further, it was found that if this material was applied to a general reinforcing steel material, a weight reduction of 17% could be achieved as compared with the FCD500 material, and further reduction in size and weight could be achieved.

[0040]

[Embodiment 3] The shape and configuration of a threaded rebar joint were the same as those of Embodiment 1, and a high-strength austempered spheroidal graphite cast iron was cast at 1415 ° C in a sand mold. The chemical components were iron, unavoidable impurities, and the components shown in Table 5.

[0041]

[Table 5]

Next, an austempering treatment was performed, and only the material was austempered spheroidal graphite cast iron. That is, the cast product after solidification was cooled to 865 ° C. in the mold, and then the cast product was taken out of the mold and kept at an austenitizing temperature of 860 ° C. for 2 hours. Further, the mixture was rapidly cooled at a cooling rate at which pearlite was not generated, the cooling was temporarily stopped at 285 ° C., gradually cooled to 240 ° C. over 2 hours, and then rapidly cooled to room temperature by water cooling. A test piece was cut out from the cast product heat-treated in this way, and the mechanical properties were examined. The results are shown in Table 6.

[0043]

[Table 6]

Spheroidal graphite cast iron JIS / FC of Embodiment 1
About 2.3 times the tensile strength was obtained as compared with D500. In addition, if this material is applied to general reinforcing steel, FCD50
It has been found that the weight can be reduced by 24% as compared with the material No. 0, and further reduction in size and weight can be achieved.

[0045]

According to the threaded rebar joint of the present invention, the two threaded rebars can be easily formed without considering the phase difference of the screw pitch of the threaded rebars to be joined by the configuration of the constituent members.
Simple and reliable connection can be ensured. Further, the material of the components of the threaded rebar joint of the present invention is made of spheroidal graphite cast iron without heat treatment, and further made of austempered spheroidal graphite cast iron, and the thread portion is manufactured with a casting surface that does not require machining, thereby reducing machining costs. , Weight and size can be reduced. Further, it is possible to provide a joint that can support high-strength rebar.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an overall configuration of a threaded bar joint according to the present invention, showing a state in which threaded bars are joined together by a threaded bar joint.

FIG. 2 is a partial cross-sectional view showing a state in which a threaded bar on one side is screwed into a female thread formed on an inner surface of a first coupler according to the threaded bar joint of the present invention.

FIG. 3 is a partial cross-sectional view showing a state in which a threaded bar on the other side is screwed into a female thread formed on an inner surface of a second coupler according to the threaded bar joint of the present invention.

FIG. 4 is a view showing a state in which a male screw portion formed on the outer surface of the first coupler and a female screw portion formed on the inner surface on one side of the collar are screwed together according to the threaded rebar joint of the present invention. It is sectional drawing.

FIG. 5 is a cross-sectional view showing a procedure for joining screw rebars by the screw rebar joint of the present invention.

FIG. 6 is a cross-sectional view showing a state in which threaded rebars are joined by a conventional steel bar joint fitting.

FIG. 7 is a cross-sectional view showing a state in which rebars are connected to each other by a conventional rebar joint.

FIG. 8 is a cross-sectional view showing a connecting procedure using a conventional reinforcing bar joint.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Threaded joint 2 First coupler 3 Second coupler 4 Collar 5 Threaded reinforcing bar on one side 6 Threaded reinforcing bar on the other side 2a Female threaded portion formed on inner surface of first coupler 2b Formed on outer surface of first coupler Male screw part 2c one end of one side of the first coupler 3a female screw part formed on the inner surface of the second coupler 3b stepped part formed on the outer surface of the second coupler 3c on the other side of the second coupler End part 3d small diameter part of outer diameter of second coupler 3e large diameter part of outer diameter of second coupler 4a female screw part formed on the inner surface on one side of collar 4b end on the other side of collar, Locking portion formed in the inner surface direction 4c Locking portion inner surface of the locking portion formed on the other end of the collar 4d Straight portion having the same inner diameter in the axial direction from the base of the locking portion inner surface at the collar inner surface 4e End of the other side of the collar 4f Color 4g Outer surface of collar 5a Male screw of screw reinforcing bar on one side 6a Male screw of screw reinforcing bar on the other side 7 Grout material injection hole 8 of second coupler ring gap portion 9 ring gap portion P ₁ pitch of bars of the external thread between the large diameter portion and the straight portion of the collar of the inner surface of the second coupler between the small diameter portion and the tip portion of the engaging portion of the collar P ₂ first female threaded portion 32b of the inner surface of the first coupler pitch 31 first coupler 31a male screw portion 32 and the second coupler 32a second coupler on the outer surface of the female threaded portion 31b first coupler of the inner surface of the first coupler of the external thread portion of the outer surface of the Second female screw portion 33 on the inner surface of the second coupler 33 One bar steel 33a One bar steel male screw 34 The other bar steel 34a The other bar steel male screw 35, 36 Spanner engaging portion A, B Reinforced concrete unit 1A Screw Reinforcing Bar 51B Reinforcing Bar 52 Helical Convex 53 Joint Body 53a Screw Hole (Hole at One End) 53b Straight Hole (Hole at Other End) 53c Screw Hole (Hole at Other End) 53d Grout Injection Port 54 Cap 55) Stopper (screw member) 55b Cylindrical part 56, 57 Lock nut

Claims (8)

[Claims] 1. A threaded joint comprising a first coupler, a second coupler, and a collar, wherein an internal thread portion is formed on an inner surface of the joint to be screwed into a male thread of a threaded bar on one side to be joined. The first coupler having an external thread formed on the outer surface thereof and an external thread portion screwed to the female thread portion of the collar, and the internal surface of the first coupler having an internal thread portion engaged with the external thread of the screw rebar on the other side to be joined. The second coupler, which is formed on the outer surface and has a stepped portion for engaging with the inner surface of the engaging portion of the engaging portion of the collar, and is disposed on the outer periphery of the first coupler and the second coupler. And a female threaded portion formed on an inner surface on one side and the collar formed with the locking portion on an end on the other side. 2. A threaded joint comprising a first coupler, a second coupler, and a collar, wherein a female screw portion screwed to a male screw of a threaded bar on one side to be joined is cast on an inner surface. The first coupler of an iron-based casting formed of a skin, and an external thread formed on the outer surface of the collar on an inner surface on one side of the collar with an internal thread formed by the casting skin on the inner surface of the collar,
On the inner surface, a female screw portion to be screwed to the male screw of the screw reinforcing bar on the other side to be joined is formed by casting skin, and on the outer surface, an engaging portion formed on the other end of the collar in the inner surface direction. The second coupler of an iron-based casting having a stepped portion for locking with the inner surface of the locking portion, and the inner surface on one side disposed on the outer periphery of the first coupler and the second coupler. The female screw portion formed of a casting surface is formed on the other side, and the locking portion is formed on the other end, and the outer surface is formed of a polygonal iron-based casting with the collar. A threaded rebar joint characterized in that: 3. A connecting means for connecting the first coupler screwed to the male screw of the threaded reinforcing bar on one side and the second coupler screwed to the male screw of the screwing bar on the other side, to one of the collars Through a threaded connection between the female screw portion formed on the inner surface of the second coupler and the male screw portion formed on the outer surface of the first coupler, the stepped portion formed on the outer surface of the second coupler; 3. The threaded joint according to claim 1, wherein the locking is performed by locking the locking portion formed at an end of the collar with an inner surface of the locking portion. 4. A straight portion having a diameter larger than the outer diameter of the second coupler and having the same inner diameter is formed on the inner surface on one side of the collar from the base of the inner surface of the locking portion of the collar. The threaded steel joint according to any one of claims 1 to 3, wherein the joint is formed up to an end of the female screw portion extending to the other side. 5. The method according to claim 1, wherein a ring-shaped gap is formed between an outer peripheral surface of the second coupler and an inner peripheral surface of the collar. Threaded rebar joint as described. 6. The threaded joint according to claim 1, wherein a grout material injection hole penetrating from an outer surface to an inner surface of the collar is formed. 7. The screw according to claim 1, wherein each material of the first coupler, the second coupler, and the collar is spheroidal graphite cast iron. Rebar joint. 8. The method according to claim 1, wherein each material of the first coupler, the second coupler, and the collar is austempered spheroidal graphite cast iron. Screw rebar joint.