WO2016092999A1 - Threaded reinforcing bar joint for deformed reinforcing bars - Google Patents

Abstract

Provided is a threaded reinforcing bar joint for deformed reinforcing bars that meets requirements for both proof tensile force and proof compression force and that facilitates construction. The reinforcing bar joint comprises: a coupler (2) into which male threaded sections (1c, 1c) are screwed, the male threaded sections being formed on facing ends of a pair of reinforcing bars (1, 1) to be mutually connected; and a pair of lock nuts (3). Each of the male threaded sections is formed to have a threaded groove in a large diameter section (W1d) having a diameter larger than a reinforcing bar body (1a), and the inner diameter (D5) that is the thread crest diameter of the coupler (2) has a diameter that is smaller than the outer diameter (D2) of a ridge (1b). A portion continuous with the male threaded section of the reinforcing bars is provided with a threaded portion (1d) on the ridge that allows the lock nut and coupler to be removed while in an engaged state. The lock nut presses the coupler by being screwed into one or both of either the male threaded section or the threaded portion on the ridge.

Description

Threaded rebar joint of deformed bar Related applications

This application claims the priority of Japanese Patent Application No. 2014-247795 filed on December 8, 2014 and Japanese Patent Application No. 2015-115663 filed on June 8, 2015, which is incorporated herein by reference in its entirety. Cited as what constitutes

This invention relates to a threaded reinforcing bar joint of deformed reinforcing bars used for reinforced concrete.

In reinforced concrete, deformed reinforcing bars are generally used as reinforcing bars. In long columns, beams, fabric foundations, etc., various reinforcing bar joints are used in order to make a limited length of reinforcing bars continuous in the field. As the reinforcing bar joint, a lap joint or a gas pressure welding joint in which the reinforcing bars are stacked by a predetermined length is generally used. However, the lap joint has a complicated bar arrangement structure due to the overlap, and the gas pressure joint has a drawback that the quality of the joint depends on the skill of the pressure welding.
Therefore, as a special joint, a joint has been developed in which grout is injected into the sleeve together with the reinforcing bar. This special joint for injecting grout is preferable from the viewpoint of simplification of the bar arrangement structure and has been put to practical use. However, it requires a period for hardening and curing the grout and has a drawback that the construction period is long.

Threaded joints have been proposed as special joints that require a short construction period (for example, Patent Documents 1 to 3). In Patent Document 1, in order to ensure the connection strength, a diameter-enlarged portion is provided at the end of the reinforcing bar, and screwing is performed, or a separate large-diameter screw shaft is joined to the end of the reinforcing bar by friction welding. Is described. In Patent Document 2, it is described as an embodiment and a conventional example that lock nuts are used on both sides of a coupler made of a screw cylinder (Patent Document 2). In Patent Document 3, as the manufacturing method of the enlarged diameter portion, in addition to the friction welding and the method of compressing by overheating, the outer diameter of the enlarged diameter portion is limited and the threading of the male screw portion is performed by rolling. Thus, it is described that a diameter-enlarged portion is formed at the time of roll molding of a deformed reinforcing bar.

JP 2002-227342 A Japanese Patent Laid-Open No. 10-61107 JP 2013-221365 A

Reinforcing bar joints are determined as building standards to withstand predetermined compressive loads in addition to tensile loads. In the threaded reinforcing bar joint, the play of the meshing portion between the male threaded portion of the reinforcing bar and the female threaded portion of the screw cylinder becomes a problem with respect to satisfying the requirements of the compressive load. That is, a prescribed play, a so-called play, is provided at the meshing portion of the screw so that the screwing operation is possible. Therefore, when changing from a tensile load state to a compressive load state, the screw thread of the female screw part that was pressed against one side of the screw thread part of the male screw part moves by the amount of play, and next to the male screw part. Will be pressed against the opposite side of the thread. Since the movement in the play is a free movement, there is a problem in satisfying the regulation of the slip amount. As the rebar diameter increases, the play also increases, and the above problem becomes greater.

This play problem can be solved by using a lock nut. However, in all conventional threaded reinforcing bar joints using lock nuts, the length of the male thread portion is provided over a range for allowing the coupler and lock nut to escape for connection work. Therefore, the length of the male screw portion is increased.

When the length of the male thread portion of the reinforcing bar becomes long, the following various problems arise.
If the deformed reinforcing bars that make up a screw-type reinforcing bar joint are not used as screw-type reinforcing bar joints but are embedded in concrete in the same way as ordinary deformed reinforcing bars, the length of the male threaded part should not include the node that is characteristic of deformed reinforcing bars. Since it does not have, the fixing power to concrete is weak. Therefore, it is difficult to use the reinforcing bar provided with the male screw part as a deformed reinforcing bar. According to the definition of deformed reinforcing bars in the building standards, how many nodes are required within a range of reinforcing bar lengths that are a predetermined multiple of the reinforcing bar diameter. If this rule is satisfied with a deformed reinforcing bar having a long male screw that allows the lock nut to be released, the interval between the joints of the portion other than the male screw portion is shortened, leading to an increase in cost. When a deformed reinforcing bar with a male thread cannot be handled as a general deformed reinforcing bar, it is complicated in terms of management, storage and handling of the reinforcing bar on site.

Further, the range for allowing the coupler, lock nut, etc. to escape in the male screw part is exposed by unscrewing the coupler or lock nut, but the exposed part of the male screw part has no node, so the fixing force is weak. The problem arises.
Moreover, when the length of the male thread is long, the tool for threading, for example, dies for rolling, and cutting tools for cutting, increases the wear of the tool. It is one of the major factors.

In addition, in order to have a length adjustment function that absorbs errors in on-site construction of reinforcing bars in threaded steel rebar joints, it is necessary to obtain intermediate drilling dimensions without contacting the opposing end faces of rebars connected to each other. An intermediate extra length may be provided in the coupler. The intermediate extra length is provided, for example, within about 10 mm. The actual size of the intermediate space is a portion hidden in the coupler and cannot be determined by visual inspection from the outside. For this reason, in order to accurately manage the intermediate drilling dimension, complicated processing such as adding a mark to the reinforcing bar and measuring it with a scale is required.

An object of the present invention is to provide a threaded reinforcing bar joint of a deformed reinforcing bar that can satisfy both requirements of tensile strength and compressive strength, can be easily constructed, and can easily form a male threaded portion. is there.
Another object of the present invention is to visually check from the outside whether or not the intermediate perforation dimension provided for absorbing construction errors between the opposing end faces of a pair of reinforcing bars connected to each other is within an allowable error range. Is to be able to do it.

The threaded reinforcing bar joint of the deformed reinforcing bar of the present invention is a reinforcing bar joint for connecting a pair of reinforcing bars, and has a male threaded portion at an opposite end of a pair of reinforcing bars connected to each other, and the male threaded portion of both reinforcing bars It has a cylindrical coupler to be screwed,
Of the pair of reinforcing bars, at least one of the reinforcing bars is a deformed reinforcing bar having a protrusion on the outer periphery of the reinforcing bar main body, and the male thread portion of the at least one reinforcing bar that is the deformed reinforcing bar has a diameter larger than that of the reinforcing bar main body. A thread groove is formed in the large diameter part of
A ridge that forms a thread groove on the ridge and allows at least a part of the coupler to escape in a state where the thread and the thread groove are fitted to the reinforcing bar in which the thread groove is formed on the large diameter portion. Provide an upper thread,
A lock nut is provided that is screwed into one or both of the male screw portion and the upper protrusion thread portion and presses the coupler.

According to this configuration, since the lock nut is provided, the contact surface between the threads of the male screw portion and the female screw portion does not change between when the tensile force is applied and when the compressive force is applied, and the play between the male screw portion and the female screw portion is not changed. The problem is solved. Therefore, both requirements on tensile strength and compression strength can be satisfied.
In addition, since the upper thread portion of the ridge that allows at least a part of the coupler to escape is provided, it is advantageous in terms of construction, unlike the case of the configuration in which escape is not possible. The part that can be escaped is provided as a threaded upper threaded part of the ridge, so that the diameter of the male threaded part is increased without providing the upper threaded part of the ridge so that the lock nut or coupler does not interfere with the ridge. Unlike the case of escape, the difference between the diameter of the male thread and the diameter of the protrusion can be reduced. Therefore, it is possible to form the large-diameter portion that forms the male screw portion at the time of roll forming of the ridge of the deformed reinforcing bar, and the selection range of the processing method for providing the male screw portion is expanded. Thereby, formation of a male screw part becomes easy.
In the present invention, either one of the reinforcing bars does not necessarily have to be a deformed reinforcing bar, and may be, for example, a round steel, or may have a large diameter as a whole without particularly having a large diameter portion. .

In this invention, the lock nut as a whole is screwed into the male screw portion, and the inner diameter that is the thread diameter of the female screw portion of the coupler and the lock nut is smaller than the outer diameter of the protrusion of the reinforcing bar, The protrusion upper thread part may have a length that allows the entire lock nut and at least a part of the coupler to escape to the protrusion upper thread part when the threaded reinforcing bar joint is connected.
As described above, when the part for allowing the coupler and the lock nut to escape for ease of construction is provided as the upper thread part of the protrusion, the male thread part compared to the case where the part for allowing the escape to be provided on the male thread part is provided. Can be shortened. Since the male screw portion can be shortened, the problem of the node pitch for securing the fixing force can be alleviated, and the processing cost of the male screw portion can be reduced.

In this invention, the coupler is provided with an intermediate surplus length that provides an allowable gap between the end surfaces of the pair of reinforcing bars, and the circle of the protrusions is between the male screw part and the upper screw part of the protrusion. If a protrusion-free section having no protrusion extending in the circumferential direction or the spiral direction is provided, and the end face on the anti-coupler side of the lock nut is positioned in the protrusion-free section, the male screw portion is at least relative to the coupler. The male thread portion, the whole of the coupler, the lock nut, and the intermediate surplus length so that the set fastening length is screwed and an appropriate screwing depth is obtained in which the allowable empty dimension is obtained. The length relationship may be set.
When the protrusion has a circumferentially extending node, the end surface of the lock nut on the side opposite to the coupler is positioned between the end of the male screw and the first node from the male screw. For example, the male threaded portion in which the threaded groove is formed in the large-diameter portion is in a proper threaded state that is a threaded state in which at least a set fastening length is threaded to the coupler and the allowable gap is obtained. As described above, a relationship among the lengths of the male screw portion, the coupler, the lock nut, and the intermediate extra length may be set.

¡If the coupler is provided with the intermediate surplus length and an allowable gap between the opposing end faces of a pair of reinforcing bars connected to each other is set, a length adjustment function can be obtained, and errors in bar construction on site can be absorbed. Whether or not the vacant dimension between the reinforcing bar end faces 1e is actually within the proper range is hidden from the coupler and cannot be seen from the outside. If the screwing amount of the male threaded part to the coupler is shallow, the required fastening length cannot be obtained, and if both screwed parts are too deep and exceed the intermediate surplus length, the male threaded part of the other reinforcing bar cannot be screwed to the required depth. . However, as described above, if the dimensional relationship of each part is set so that the appropriate threading depth is obtained when the end face of the lock nut is located in the no-protrusion section, the end face of the coupler is free from the male thread and the protuberance. It is only necessary to look at the section, and it can be easily determined by visual inspection from the outside whether or not the screwing state is appropriate.

In this configuration, both of the pair of reinforcing bars are the deformed reinforcing bars, and have the male threaded portion in which a thread groove is formed in the large-diameter portion, and both the reinforcing bars have the upper threaded thread portion. In addition, both the reinforcing bars may have the appropriate screwing depth if the end face on the anti-coupler side of the lock nut is located in the no-protrusion section.
As a result, the length of the male threaded portion can be shortened without any disadvantages in construction, and the problem of the pitch of the ridges for securing the fixing force can be alleviated, and the processing cost of the male threaded portion can be reduced. Can be obtained more effectively. In addition, it is possible to easily determine whether or not the male screw portion is in a proper screwed state with respect to the coupler with respect to both the reinforcing bars from the outside.

In this invention, a part or the whole of the lock nut may be screwed into the upper protrusion thread portion.
As described above, since the lock nut is provided, both the requirements on the tensile strength and the compression resistance can be satisfied. In this case, when at least a part of the lock nut is engaged with the upper thread portion of the ridge, the upper thread portion of the ridge is less hooked on the lock nut than the large-diameter male thread portion. Does not act on the lock nut, and the compression resistance may be half the yield strength. Therefore, even if a lock nut is provided on the upper thread portion of the ridge, the compression resistance can be satisfied.

As described above, since at least a part of the lock nut is provided in the upper thread portion of the ridge, the length of the male thread portion of the large diameter portion can be shortened. The joint of the upper thread portion of the ridge has a lower actual joint height due to the formation of the thread groove, and the fixing force is weaker than that of the general portion. The actual height of is not less than ½ of the height of the node of the general part. For this reason, in calculating the number of joints provided in the specified reinforcing bar length range with respect to the reinforcing bar diameter, the joints on the upper threaded part of the ridge can be handled in the same way as the joints of the general part, and the building law standards for deformed bars are satisfied. it can. Therefore, the reinforcing bar provided with the male thread portion can be handled in the same manner as a general deformed reinforcing bar while allowing the lock nut to be bitten, and the trouble of management and on-site storage and handling of the reinforcing bar can be reduced.

Further, the upper thread portion of the ridge needs to be threaded, but the amount of processing is less than that of the large-diameter male thread portion, and the tool wear with respect to the screw length is small. In this way, since the tool wear is small in the machining of the upper thread portion of the ridge and the length of the male screw portion of the large diameter portion is short as described above, the wear of the tool in the screw machining, for example, die, cutting in rolling Machining reduces wear of the tool and suppresses an increase in cost due to a decrease in tool life in screw machining.
As described above, the threaded reinforcing bar joint having a configuration in which at least a part of the lock nut is provided on the upper thread portion of the ridge is a male thread portion that can satisfy both the requirements for tensile strength and compression strength and is a large diameter portion. Therefore, the problem of the node pitch for securing the fixing force can be alleviated, and an increase in the processing cost of the male screw portion can be suppressed. That is, two effects that are difficult to achieve in terms of strength and cost can be achieved.

In the case of this configuration, both of the pair of reinforcing bars are the deformed reinforcing bars, and the male threaded portion is formed in the large diameter portion with respect to both the reinforcing bars, and the protrusion upper threaded portion and the lock nut are It may be provided.

In this invention, either one of the reinforcing bars does not necessarily have to be a deformed reinforcing bar, for example, round steel, and the whole may have a large diameter without having a large diameter part, As described above, when both of the pair of reinforcing bars are deformed reinforcing bars as described above and have a nodal screw portion and a lock nut, the problem of the protrusion pitch for securing the fixing force in the present invention is alleviated. The effect that the increase in the processing cost of the male screw portion can be suppressed is even more remarkable.

In the case where the entire lock nut is provided in the upper thread portion of the protrusion, the lock nut has a length in which 2 to 4 threads of the upper thread portion of the protrusion engage with each other in a cross section along the axial direction. Also good.
As mentioned above, since the compression resistance can be halved with respect to the yield point strength, the length of the lock nut can be shortened, and if the length of the thread of the joint screw part meshes, The required compression resistance can be satisfied. The engagement length may be slightly increased with a margin, but if the length of engagement is more than four, the cost reduction effect due to reduction of tool wear is reduced.

In this invention, the groove top screw portion may have a groove bottom diameter smaller than the outer peripheral surface of the reinforcing bar main body, and the thread groove bottom portion of the protrusion upper screw portion may be formed in the reinforcing bar main body.
When the groove bottom portion of the upper thread portion of the ridge is formed in the reinforcing bar main body, a compressive force can be borne at the bottom portion of the thread groove, and the compression resistance of the threaded reinforcing bar joint is improved.

In this invention, the deformed reinforcing bar may have a rib extending in the longitudinal direction, and the upper thread portion of the protrusion may have the thread groove on the rib.
In the case of a deformed reinforcing bar with a rib, the protrusion upper threaded portion is also provided on the rib, so that the hooking with the female threaded portion of the screw cylinder increases, and the compression resistance of the threaded reinforcing bar joint is improved.

In this invention, the deformed reinforcing bar may have an outer diameter of the large-diameter portion that is equal to or smaller than a maximum reinforcing bar outer diameter including the protrusion of the deformed reinforcing bar.
If the outer diameter of the large-diameter portion that becomes the male screw portion is equal to or less than the maximum outer diameter of the reinforcing bar including the protrusion of the deformed reinforcing bar, the large-diameter portion may interfere with the guide roller at the time of forming the ridge roll, thereby preventing feeding. In addition, the large-diameter portion can be formed at the time of rolling the node portion of the deformed reinforcing bar. Therefore, productivity of the reinforcing bar having the male screw portion is improved.
Thus, when forming the large-diameter portion when rolling the node portion of the deformed reinforcing bar, unlike the configuration in which the male screw member of another member is joined by friction welding or the like, the male screw portion of the large-diameter portion and the upper screw portion Are continuously processed with a tool such as the same die, in which case the effect of reducing the tool wear in the present invention becomes significant.

In the present invention, each of the reinforcing bars is formed by roll forming an iron wire material, and the joint portion and the large-diameter portion are formed. Also good.
If the large diameter portion forming the male screw portion is formed during roll forming of the ridge, the large diameter portion can be formed without increasing the number of processing steps, and productivity is improved. As described above, the relief portion of the coupler and the lock nut is provided by the upper thread portion of the ridge, so that the large diameter portion can reduce the difference in diameter from the ridge and roll forming is possible. Further, when the protrusion upper thread portion is a rolled screw, unlike the case of machining, the cross-sectional dimension of the reinforcing bar is not changed, and the strength can be ensured while being provided on the protrusion. By forming not only the upper thread part of the ridge but also the male thread part as a rolling screw, the upper thread part of the ridge and the male thread part can be formed together, and productivity is improved.

Any combination of at least two configurations disclosed in the claims and / or the specification and / or the drawings is included in the present invention. In particular, any combination of two or more of each claim in the claims is included in the invention.

The present invention will be more clearly understood from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are for illustration and description only and should not be used to define the scope of the present invention. The scope of the invention is defined by the appended claims. In the accompanying drawings, the same part numbers in a plurality of drawings indicate the same or corresponding parts.

It is sectional drawing of the screw-type reinforcing bar joint of the deformed reinforcing bar which concerns on one Embodiment of this invention. (A)-(C) are longitudinal cross-sectional views showing examples of appropriate screwing amounts of the same threaded reinforcing bar joint. It is a partial expanded sectional view which expands and shows the meshing part of the thread part of the screw-type rebar joint. (A) And (B) is a partial front view which shows the state before and behind the process of the external thread part in a screw-type rebar joint, and a thread upper thread part, respectively. It is explanatory drawing which shows the mode of roll forming of the reinforcing bar used for the screw-type reinforcing bar joint. It is explanatory drawing which shows the rolling process of the external thread part of a reinforcing bar in which the same roll forming was performed, and a protrusion upper thread part. (A) And (B) is a middle abbreviation front view of each example of a reinforcing bar used for the screw type reinforcing bar joint. It is sectional drawing which shows the example from which the shape of the protrusion in the screw-type reinforcing bar joint differs. It is sectional drawing which shows the other example from which the shape of the protrusion in the screw-type reinforcing bar joint differs. It is sectional drawing of the screw-type reinforcing bar joint of the deformed reinforcing bar which concerns on further another embodiment of this invention. (A) And (B) is a partial front view which shows the state before and behind the process of the external thread part in the same screw type reinforcing steel joint, and a nodal upper thread part. (A) And (B) is a middle abbreviation front view of each example of a reinforcing bar used for the screw type reinforcing bar joint.

An embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the threaded reinforcing bar joint of the deformed reinforcing bar is a reinforcing bar joint that connects a pair of reinforcing bars 1 and 1, and has a male threaded portion 1 c at opposite ends of the pair of reinforcing bars that are connected to each other. A coupler 2 that is a screw cylinder that is screwed over the male screw portions 1c and 1c of both the reinforcing bars 1 and 1, and a pair of lock nuts that are screwed into the male screw portions 1c and 1c and press the coupler 2 respectively. 3 and 3.

Each reinforcing bar 1 is a deformed reinforcing bar having a protrusion 1b on the outer peripheral surface of a round shaft-shaped reinforcing bar main body 1a. In the example of FIG. 1, the protrusion 1 b includes a node portion 1 ba extending in the circumferential direction and a rib 1 bb extending in the longitudinal direction. Two ribs 1bb are provided at positions 180 degrees apart in the circumferential direction of the reinforcing bar main body 1a. Each node 1ba has an annular shape that continues around the entire circumference. In addition, each node part 1ba may be provided by the half circumference alternately by the rib 1bb as a boundary.
In addition to this, as shown in FIG. 8, the protrusion 1b of each reinforcing bar 1 extends in a spiral shape in two different directions and forms a rhombic mesh shape in a side view, and is inclined in two directions 1bc and 1bc. And the shape which consists of rib 1bd extended in a longitudinal direction may be sufficient. Two ribs 1bd are provided at a position 180 degrees away from the reinforcing bar main body 1a. The inclined ridge portions 1bc and 1bc may be offset in the axial direction from each other on both sides of the rib 1bd. In addition, the protrusion 1b may have a spiral extending shape as shown in FIG.

As shown in FIGS. 4A and 4B, the male screw portion 1c of each reinforcing bar 1 which is the deformed reinforcing bar has an outer diameter D3 larger than the outer diameter D1 of the reinforcing bar main body 1a excluding the protrusion 1b. A large-diameter portion W1d (FIG. 4 (A)) having a thread is formed with a thread groove as shown in FIG. 4 (B). Large diameter part W1d is formed at the time of roll forming of node part 1ba of reinforcing bar 1. The male screw portion 1c is provided over the entire length e of the large diameter portion W1d. Following the thread groove of the male threaded portion 1c, a protrusion upper threaded portion 1d for allowing the lock nut 3 and the coupler 2 as a whole to escape to the outer periphery of the reinforcing bar 1 in a screwed state is provided for a predetermined length f. It has been.

The protrusion upper thread portion 1d is formed by forming thread grooves in the joint portion 1ba and the rib 1bb in a general portion other than the male screw portion 1c of the reinforcing bar 1 made of the deformed reinforcing bar. The upper thread portion 1d of the ridge may be formed only on the node portion 1ba and the rib 1bb. However, in this example, the thread groove bottom diameter D4 is smaller than the outer diameter D1 of the reinforcing bar main body 1a. The bottom of the thread groove of the upper thread portion 1d is also formed on the reinforcing bar main body 1a. The thread grooves of the male screw portion 1c and the upper protrusion thread portion 1d have the same diameter and the same lead. The thread grooves of the male threaded portion 1c and the protrusion upper threaded portion 1d are processed by rolling or the like.

In this example, the thread groove of the upper thread portion 1d of the ridge is the same as the cross-sectional shape of the male thread portion 1c (however, the thread groove of the upper thread portion 1d of the ridge is a cross section of the male thread portion 1c depending on the circumferential portion. However, the thread groove of the upper thread portion 1d of the protrusion only needs to be able to escape the lock nut 3 and the like, and the load is not transmitted. Therefore, the thread of the coupler 2 and the lock nut 3 It may have a cross-sectional shape that fits loosely.

The predetermined length f of the upper thread portion 1d of the ridge is set so that one lock nut 3 and the whole of the coupler 2 are screwed into the one reinforcing bar 1 at the time of construction until the coupler 2 does not protrude from the reinforcing bar end surface 1e. Dimension that can be. Therefore, the predetermined length f is a dimension (e + f) obtained by adding the length f and the large diameter full length e (e + f), and a dimension (b + c) obtained by adding the lock nut length c to the coupler length b (see FIG. 1). This is the length. The large-diameter portion total length e, the coupler length b, and the lock nut length c are determined as described later.

In FIG. 1, the coupler 2 is a screw cylinder whose entire inner periphery is a female thread portion 2 a, and a fastening length sufficient to ensure the tensile strength required as a reinforcing bar joint for the male thread portion 1 c of the reinforcing bar 1. a is required. The inner diameter D5, which is the thread diameter of the female thread portion 2a of the coupler 2, is smaller than the outer diameter D2 of the protrusion 1b of the reinforcing bar 1 (or the outer diameter of the node portion 1ba when it has the node portion 1ba).

Further, if the pair of reinforcing bars 1 and 1 that are screwed into the coupler 2 are designed so that the end faces 1e and 1e come into contact with each other, the construction error of the reinforcing bar cannot be absorbed. An intermediate surplus length d that is a setting allowable range is provided between the facing end faces. Therefore, the coupler length b which is the entire length of the coupler 2 is
b = 2a + d
It is said.

The length c of the lock nut 3 is a length that can ensure the compressive strength required for the reinforcing bar joint. This is because the lock nut 3 has a role of transmitting a compressive force as follows. This will be described with reference to FIGS. 3 and 4A and 4B.

The outer diameter of the external thread 1c in FIG. 4B, that is, the outer diameter D3 of the large-diameter portion W1d of the reinforcing bar 1 in FIG. 4A is the outer diameter of the ridge 1b of the reinforcing bar 1 which is the deformed reinforcing bar ( It is preferable that the maximum outer diameter D2) of the reinforcing bars including the node portion 1ba and the rib 1bb is not more than. In particular, when the large-diameter portion W1d is formed during roll forming of the node portion 1ba, it is effective to make the relationship between the outer diameters D2 and D3. That is, when the outer diameter D3 of the large-diameter portion W1d is equal to or less than the maximum rebar outer diameter D2 that is the outer diameter of the node portion 1ab, the large-diameter portion W1d is caught by the roll that guides the rebar 1 during roll forming of the node portion 1ba. It can be done smoothly. Regardless of the threading method, if the outer diameter D3 of the large-diameter portion W1d is equal to or less than the rebar maximum outer diameter D3 that is the outer diameter of the node portion 1ba, the upper screw portion 1d is moved to the groove of the screw groove. It becomes easy to process so that the bottom is formed in the shaft portion 1a.

According to the threaded reinforcing bar joint of the deformed reinforcing bar having this configuration, since the lock nut 3 is provided, the screw thread between the male threaded portion 1c of the reinforcing bar 1 and the female threaded portion of the coupler 2 when the tensile force is applied and when the compressive force is applied. The surfaces in contact with each other do not change regardless of the engagement play δ of FIG. 3 provided as a tolerance. That is, by tightening with the lock nut 3, the thread of the female thread portion 2 a of the coupler 2 is pressed against the surface 1 ca on the lock nut 3 side of the thread of the male thread portion 1 c of the reinforcing bar 1. Further, the thread of the female thread 3a of the lock nut 3 is pressed against the surface 1da on the coupler 2 side of the thread of the joint thread 1d of the reinforcing bar 1. Therefore, even if the force acting on the reinforcing bar 1 changes between the pulling direction and the compressing direction, the reinforcing bar 1 and the coupler 2 slide relative to each other due to the play δ in the engagement between the male screw part 1c and the female screw part 2a of the coupler 2. It does not move and can therefore satisfy both the tensile and compressive strength requirements.

The lock nut 3 is at least partially engaged with the nodal screw portion 1d, and the nodal screw portion 1d has a smaller allowance than the hook on the coupler 2 of the male screw portion 1c of the large diameter portion W1d. No tensile force acts on the meshing part 3, only a compressive force acts, and in the case of a reinforced joint, the compression resistance may be half of the yield point strength. The tensile strength and compression resistance can be secured.

This will be described with reference to FIG. When a tensile force (indicated by a solid arrow in the figure) acts on the reinforcing bars 1 and 1 on both sides, the surface 1ca on the coupler 2 side of the thread of the male threaded part 1c of the reinforcing bar 1 causes the female threaded part 2a of the coupler 2 to A tensile force is transmitted to the surface 2aa on the coupler center side in the thread. Accordingly, the tensile force is directly transmitted from one reinforcing bar 1 to the nut 2 and is transmitted to the other reinforcing bar 1, and the meshing strength of the lock nut 3 does not affect the transmission of the tensile force.

When compressive force (indicated by broken arrows in the figure) is applied to the reinforcing bars 1 and 1 on both sides, the female thread of the lock nut 3 from the surface 1da on the anti-coupler side in the thread of the joint thread 1d of the reinforcing bar 1 The compressive force is transmitted to the coupler-side surface 3aa in the thread of the portion 3a. The transmitted compressive force is transmitted to the coupler 2 from the contact surface between the lock nut 3 and the coupler 2. That is, the compressive force is transmitted from one reinforcing bar 1 to the other reinforcing bar 1 through the lock nut 3, the coupler 2, and the other lock nut 3. For this reason, the strength of meshing by the threading allowance between the knot upper thread portion 1d of the reinforcing bar 1 and the lock nut 3 affects the compression resistance as a reinforcing bar joint. When the meshing strength by the lock nut 3 is weak, the rebar 1 and the coupler 2 come into contact with each other on the thread surface by relative movement by the play δ.
However, in a reinforcing bar joint, the compression resistance is about half that of the yield strength. Therefore, the necessary compression resistance can be obtained also by the joint upper screw portion 1d formed in the joint portion 1ba of the reinforcing bar. In the reinforcing bar 1 having the rib 1bb, the nodal upper screw portion 1d is also provided in the rib 1bb, but the nodal upper screw portion 1d is also provided in the rib 1bb, and the screw groove bottom of the nodal upper screw portion 1d is the reinforcing bar main body 1a. In the case where it is formed, a larger allowance is obtained, and the compression resistance is further improved.

Thus, since at least a part of the lock nut 3 is provided in the knot upper screw portion 1d, the length of the male screw portion 1c of the large diameter portion W1d can be shortened. The node portion 1ba of the node upper screw portion 1d has a substantially lower node height due to the formation of the screw groove, and the fixing force is weaker than that of the node portion 1ba of the general portion. The substantial height of the portion 1d is not less than ½ of the height of the node portion of the general portion. Therefore, in the calculation of the number of node portions 1ba provided in a predetermined reinforcing bar length range with respect to the reinforcing bar diameter, which is required for the deformed reinforcing bar from the viewpoint of fixing strength with respect to the reinforced concrete, the node portion 1ba of the upper screw portion 1d is also a node portion of the general portion. It can be handled in the same way as 1ba, and can satisfy the building standards for deformed reinforcing bars. Accordingly, the rebar 1 provided with the male thread portion 1c can be handled in the same manner as a general deformed rebar while allowing the lock nut 3 to be bitten, and the management and the trouble of storing and handling the rebar in the field can be reduced. .

Further, although the upper thread portion 1d needs to be threaded, the amount of processing is smaller than that of the male thread portion 1c of the large diameter portion W1d, and the tool wear with respect to the screw length is small. Thus, since the tool wear is small in the machining of the upper screw portion 1d and the length of the male screw portion 1c of the large diameter portion W1d is short as described above, the tool wear in the screw machining, for example, the die for rolling In cutting, wear of the cutting tool is reduced, and an increase in cost due to a decrease in tool life in screw machining can be suppressed. In threaded reinforcing bars, the tool life of screw machining is a major factor in cost increase, but this can be suppressed and cost reduction can be achieved.
As described above, the threaded reinforcing bar joint of the deformed reinforcing bar of this embodiment can satisfy both the requirements for the tensile strength and the compression resistance, and the length of the male screw portion 1c formed in the large diameter portion W1d is shortened. Thus, the problem of the node pitch for securing the fixing force can be alleviated, and an increase in the processing cost of the male screw portion can be suppressed.

As described above, the required length of each part is determined in the reinforcing bar joint, and an intermediate surplus length d that is a setting allowable range is provided between the opposing end surfaces 1e and 1e of the pair of reinforcing bars 1 and 1 shown in FIG. However, since the distance between the opposing end faces of the pair of reinforcing bars 1 and 1 is actually in the coupler 2, it cannot be seen from the outside. Therefore, in the embodiment shown in FIG. 8, it is appropriate if a protrusion-free section h is provided between the male screw portion 1 c and the protrusion upper screw section 1 d and the end surface of the lock nut 3 is positioned in the protrusion-free section 9. The dimensional relationship of each part is set so as to be screwed. The rib-free section 9 is a section without the protrusion 1b extending in the circumferential direction or the spiral direction of the outer periphery of the reinforcing bar 1, and the rib 1bb that is a protrusion extending in the axial direction may exist.

Specifically, the dimensional relationship is such that, when the protrusion 1b has a shape of the node portion 1ba and the rib 1bb as in this embodiment, the end face 3b on the anti-coupler side of the lock nut 3 is a male screw portion. If it is located between the end of 1c and this first threaded portion 1ba1 from the male threaded portion 1c, the male threaded portion 1c is screwed into the coupler 2 at least for the set fastening length a and the tolerance The relationship between the lengths e, b, c of the male screw portion 1c, the coupler 2, and the lock nut 3 and the length of the intermediate extra length d so that a proper screwed state is obtained in which a gap is obtained. Is set. In this example, the portion between the first node portion 1ba1 and the male screw portion 1c is the no-protrusion section h. In the case of the reinforcing bar 1 having the spirally extending protrusion 1b as in the examples of FIGS. 8 and 9, the protrusion-free section h is provided so that the protrusion 1b is interrupted. The length c of the lock nut 3 is a fastening length, and when the lock nut 3 has a portion not having a female screw at one end or both ends of the female screw portion 3a, the length c of the portion is set to the length c. The total length of the lock nut 3 is obtained by adding the length.

In this embodiment, an example of the dimensional relationship of each part in the case of the following two types of steel materials will be described. Table 1 is an example in the case of SD390, and Table 2 is an example in the case of SD490.
In either case, the height of the lock nut 3 is based on the relationship of the intermediate surplus length d.
_PN L = (2e + d) −b) / 2
It is said that.

According to the threaded reinforcing bar joint of the deformed reinforcing bar having this configuration, the connecting operation is performed as follows. The coupler 2 and one of the lock nuts 3 are, as shown by a one-dot chain line in FIG. 1, until the end of the coupler 2 does not protrude from the reinforcing bar 1 and the male threaded portion 1c of the reinforcing bar 1 and the upper threaded portion of the ridge. Screw onto 1d and leave. Only the lock nut 3 is screwed into the upper thread portion 1d of the ridge on the other reinforcing bar 1. In this state, the ends of the reinforcing bars 1 and 1 on both sides are opposed to each other, and the coupler 2 is screwed back and screwed over the male screw parts 1c and 1c of the reinforcing bars 1 and 1 on both sides. Next, each lock nut 3 is screwed back until it is pressed against the coupler 2.
In this state, whether or not the end face 3b on the anti-coupler side of the lock nuts 3 and 3 on both sides is positioned in the protrusion-free section h (in this example, one end from the male screw portion 1c and one from the male screw portion 1c). Whether or not it is positioned between the joint 1ba1 of the eye). That is, it is confirmed whether or not the male screw portion 1c is hidden in the lock nut 3 and whether or not the first nut portion 1ba1 has entered the lock nut 3. In this case, it is desirable that the length from the end surface 3b of the lock nut 3 on both sides to the first node 1ba1 is substantially the same. If the above conditions are not satisfied, the lock nut 3 is loosened, the position of the coupler 2 is adjusted to the screwed position, the lock nut 3 is tightened again, and the above confirmation is repeated.

In this embodiment, if both end faces 3b of the lock nuts 3 on the side opposite to the coupler are located in the no-protrusion section h, that is, the end of the male threaded part 1c and the first part from the male threaded part 1c. If the male screw portion 1c is positioned between the joint portion 1ba1 and the coupler, at least the set fastening length a, and the appropriate screwing depth in which the allowable clearance is obtained is obtained. The relationship between the lengths of the respective parts is determined. Therefore, it can be easily confirmed visually whether or not the screwing depth is appropriate.

2 (A) to 2 (C) all show the proper screwing state, FIG. 2 (A) shows the state where the middle empty dimension is the largest, and FIG. 2 (C) shows that the empty dimension is zero. The state in which the reinforcing bars 1 and 1 on both sides are abutted, FIG. In FIG. 2A, the entire lock nut 3 is screwed into the male screw portion 1c. If the male screw portion 1c protrudes from the end surface b of the lock nut 3 than in this state, the screw thread is improperly engaged. 2 (B) and 2 (C), a part of the lock nut 3 is screwed into the projecting upper screw portion 1d. Even in the state of FIG. 2A, a part of the lock nut 3 may be screwed into the projecting upper screw portion 1d.

Since the screw-type reinforcing bar joint of this configuration is provided with the lock nut 3, the surface where the threads of the male screw portion 1c and the female screw portion 2a contact with each other is not changed between when the tensile force is applied and when the compressive force is applied. The problem of play between the portion 1c and the female screw portion 2a is eliminated. Therefore, both requirements on tensile strength and compression strength can be satisfied. The portion for allowing the coupler 2 and the lock nut 3 to escape for easy installation is provided as a protrusion upper screw portion 1d at a location following the male screw portion 1c, so that the portion for allowing the male screw portion 1c to escape is provided. The male threaded portion 1c can be shortened compared to the case where it is provided. Since the male screw portion 1c can be shortened, the problem of the pitch of the node portion 1ba for securing the fixing force can be alleviated, and the processing cost of the male screw portion 1c can be reduced.

Moreover, since the upper thread part 1d of the protrusion is provided so that the lock nut 3 and the coupler 2 can be released to the outer periphery of one of the reinforcing bars 1 during construction, the construction can be easily performed and there is a disadvantage in construction. Absent. Since the portion that can be escaped is provided as the protrusion upper screw portion 1d, the diameter of the male screw portion 1c is increased without providing the protrusion upper screw portion 1d so that the lock nut 3 and the coupler 2 do not interfere with the node portion 1ba. Thus, unlike the case of escape, the difference between the diameter e of the male screw portion 1c and the diameter D2 of the protrusion 1b can be reduced. Therefore, the large-diameter portion w1d that forms the male screw portion 1c can be formed at the time of roll forming the deformed reinforcing bar node 1ba, and the selection range of the processing method for providing the male screw portion 1c is expanded.

In addition, each of the reinforcing bars 1 and 1 is formed by roll forming an iron wire material, and the node portion 1ba and the large-diameter portion w1d are formed, and the male screw portion 1c and the protrusion upper screw portion 1d are rolled. It is considered as a screw making. Therefore, the following advantages are obtained. When the large diameter portion w1d for forming the male screw portion 1c is formed at the time of roll forming the node portion 1ba, the large diameter portion w1d can be formed without increasing the number of processing steps, and the productivity is improved. As described above, the relief portion of the coupler 2 and the lock nut 3 is provided by the protrusion upper screw portion 1d. Therefore, the large-diameter portion w1d can reduce the difference in diameter from the node portion 1ba, and roll forming is possible. Moreover, although the said protrusion upper thread part 1d can be formed also by cutting, the cross-sectional dimension of the reinforcing bar 1 does not change if it is a rolling screw unlike the case where it cuts. Therefore, since the effective cross-sectional area of the screw portion does not decrease, the strength can be ensured while the screw portion is provided in the node portion 1ba. By forming not only the protrusion upper screw portion 1d but also the male screw portion 1c as a rolling screw, the protrusion upper screw portion 1d and the male screw portion 1c can be formed together, and productivity is improved.

FIGS. 5 to 7 show an example of a manufacturing method in the case where the node portion 1ba and the large diameter portion W1d of the reinforcing bar 1 used in the threaded reinforcing bar joint are manufactured by rolling.
As shown in FIG. 5, the protrusion 1b (node 1ba and rib 1bb) is formed by rolling by roll forming by passing an iron round bar-shaped wire W0 as a raw material between the forming rolls 11 and 11. . This shaping is performed while heating the wire W0. In the process of roll forming by the forming rolls 11, 11, the large diameter portion W1d is provided. Specifically, the forming rolls 11 and 11 are provided with a recess (not shown) for forming the protrusion 1b of the reinforcing bar 1 on the outer peripheral surface serving as a forming die surface. , 11 is a large-diameter-portion-forming recess 11a. The circumferential length of the large-diameter portion molding recess 11a is the length e of the large-diameter portion W1d to be molded, or twice that length. When roll forming is performed with this forming roll 11, a part in the length direction becomes the large-diameter portion W1d, and the protrusion 1b is formed in the remaining length range portion (corresponding to the general portion).

Since the large diameter portion W1d is not more than the maximum outer diameter D2 of the reinforcing bar, the material deformed reinforcing bar W1 in a heated state in contact with the protrusion 1b of the deformed reinforcing bar W1 of the material deformed by roll forming of the long deformed reinforcing bar W1 as the material. The deformed reinforcing bar W1 is manufactured without causing the problem of bending of the deformed reinforcing bar W1 due to the diameter expanding part W1d not contacting the guide 12 such as a roll or the like, so that the diameter expanding part W1d contacts the guide 12. Can do.

The deformed reinforcing bar W1 which is the material thus manufactured is cut at the end of the large-diameter portion W1d, and the deformed reinforcing bar W1 with a large-diameter portion having a predetermined length having the large-diameter portions W1d at both ends. Get multiple. In addition, when shape | molding the large diameter part twice as long as the large diameter part W1d in the material deformed reinforcing bar W1, it cut | disconnects in the middle.
The deformed reinforcing bar W1 with the enlarged portion having a predetermined length obtained in this way is a multiple of a module (eg, 910 mm, 1000 mm, etc.) of a module designed as a module when applied to the foundation of a building such as a house. Or a multiple of 1/2 the length of the module.

The male threaded portion 1c is processed by rolling between the pair of rolling rolls 13 and 13, as shown in FIG. 6, on the large-diameter portion W1d of the cut deformed reinforcing bar W1. The reinforcing bar 1 has a male screw part 1c having a diameter. The pair of rolling rolls 13 and 13 are arranged apart from each other as shown in the figure, and after the enlarged diameter portion W1d is positioned between the rolling rolls 13 and 13, both rolling rolls 13 are provided. , 13 are pressed against the large-diameter portion W1d while rotating in the radial direction as indicated by arrows. During this rolling process, the deformed reinforcing bar W1 with a large diameter portion is fed between the rolling rolls 13 and 13 even after the male screw portion 1c is rolled, and the upper thread portion 1d on the ridge following the male screw portion 1c (FIG. 4 ( B)) is rolled.

In the case of roll forming as described above, the reinforcing bar 1 constituting the reinforcing bar joint may have a large diameter portion W1d left in the middle as shown in FIGS. 7 (A) and 7 (B). Since the diameter of the molding roll 11 (FIG. 5) is limited, when the reinforcing bar 1 is longer than the circumferential length of the molding roll 11, the large-diameter portion W1d remains in the middle. FIG. 7A shows an example in which a large-diameter portion W1d having a length twice that of the male screw portion 1c is provided in the middle. In order to allow the lock nut 3 to escape to the upper thread portion 1d of the ridge during connection work, the length of the large-diameter portion W1d remaining in the middle is short, and the fixing force to the concrete is reduced due to the formation of the large-diameter portion W1d. Alleviated.

Further, the enlarged diameter portion W1d may be provided with a node portion 1ba ′ similar to the general portion, as shown in FIG. 7B, in one or a plurality of axial directions on the outer peripheral surface. Thereby, the fixing power to concrete improves. The node 1ba ′ is formed at the time of roll forming by the forming roll 11. The height of the node 1ba ′ may be the same as the outermost diameter D2 of the reinforcing bar which is the outer diameter of the node 1ba, or may be formed higher or lower than this. When making it higher than the outermost diameter D2 of a reinforcing bar, it is set as the height which does not cause trouble at the time of roll forming. The node portion 1ba ′ of the large diameter portion W1d at the end portion is not crushed when the male screw portion 1c is rolled, but rolling may be performed after the large diameter portion W1d is processed into a perfect circle. The node portion 1ba ′ of the large diameter portion W1d is not necessarily provided. In the example of FIG. 7B, the large diameter portion W1d has a specification in which the rib 1bb is not formed and the node portion 1ba ′ is interrupted at the circumferential position of the rib 1bb for convenience of roll forming. Even in the enlarged diameter portion W1d, the specification may be such that the node portion 1ba ′ is continuous over the entire circumference or the specification in which the rib 1bb is present.

In the above embodiment, both the reinforcing bars 1 and 1 connected to the screw cylinder have the male screw portion 1c in the large-diameter portion W1d, and the protruding portion upper screw portion 1d in the general portion. One reinforcing bar 1 does not necessarily have the large diameter portion W1d. For example, the male screw portion 1c is processed into a round shaft having a large diameter as a whole, and the male screw portion 1c is elongated to provide the lock nut 3. You may do it.
In the above-described embodiment, the lock nuts 3 are provided on both sides of the coupler 2. However, if the lock nut 3 can control the slip amount even with one of the couplers 2, the lock nut 3 may be provided only on one side.

10 to 12 show still another type of threaded reinforcing bar joint of deformed reinforcing bars of the present invention. The threaded reinforcing bar joint of the deformed reinforcing bar is a reinforcing bar joint for connecting a pair of reinforcing bars 1 and 1, and has a male threaded portion 1 c at the opposite end of the pair of reinforcing bars connected to each other. The male screw portion 1c is provided with a coupler 2 formed of a screw cylinder that is screwed into the male screw portion 1c.

Among the pair of reinforcing bars 1, 1, at least one reinforcing bar 1, in this embodiment, both reinforcing bars 1, 1 have a ridge 1b on the outer peripheral surface of a round shaft-shaped reinforcing bar main body 1a. As this protrusion 1b, the node part 1ba extended in the circumferential direction and the rib 1bb extended in a longitudinal direction are provided. Two ribs 1bb are provided at positions 180 degrees apart in the circumferential direction of the reinforcing bar main body 1a. The feature of this threaded reinforcing bar joint is that each node portion 1ba shown in FIG. 10 is alternately provided on a half circumference with the rib 1bb as a boundary. The node 1ba has a shape that follows the entire circumference as described above with reference to FIG. 1, or a rhombus-like mesh shape formed by two- direction protrusions 1b and 1b that extend in two different directions as described above with reference to FIG. Alternatively, the spirally extending shape described above with reference to FIG. 9 may be used.

As shown in FIG. 11, the male screw portions 1c, 1c of the reinforcing bars 1, 1 which are deformed reinforcing bars have a large diameter portion W1d having an outer diameter D3 larger than the outer diameter D1 of the reinforcing bar main body 1a (FIG. 11). (A)), a thread groove is formed as shown in FIG. 5B. Following this thread groove, a nodal upper thread portion 1d in which a thread groove is formed in the nodal portion 1ba and the rib 1bb, It is provided in the general part which is a part other than the male screw parts 1c, 1c of the reinforcing bar 1 made of the deformed reinforcing bar. The male screw portion 1c is provided over the entire length L1 of the large diameter portion W1d, and the nodal upper screw portion 1d is formed in a range of a predetermined length L2 of the general screw portion following the large diameter portion W1d.

As shown in FIG. 10, on both sides of the coupler 2, lock nuts 3 that press one side against the coupler 2 are provided on the joint upper screw portion 1 d. It is preferable that the lock nut 3 has a length in which two or more, for example, 2 to 4 threads of the nodal upper screw portion 1d are engaged in the longitudinal section along the axial direction. Only a part of the lock nut 3, for example, 1/4 to 3/4 or 1/3 to 2/3 of the axial length, is screwed into the joint upper screw part 1 d and the other part is screwed into the male screw part 1 c. Has been. However, the entire lock nut 3 may be screwed into the knot upper screw portion 1d.
The predetermined length L2 (FIG. 11) that forms the knot upper thread portion 1d of the reinforcing bar 1 is such that the lock nut 3 and the coupler 2 are entirely connected to the male thread portion 1c and the knot upper thread portion 1d during joint connection work. The large diameter portion overall length (the length of the male screw portion 1c) L1 and the predetermined length L2 of the knot upper screw portion 1d are larger than the combined length of the coupler 2 and the lock nut 3 so that the screw portion can be released. It is preferable that the predetermined length L2 is determined so that the combined length becomes longer.

10 and 11, the method for forming the male thread portion 1 c of the reinforcing bar 1 is roll forming as described above with reference to FIGS. 5 and 6. The large-diameter portion W1d may be formed not only by roll forming but also by a diameter expanding process in which a deformed reinforcing bar is partially subjected to high-frequency induction heating to apply a compression force, and a male screw member separate from the deformed reinforcing bar is rubbed. It is good also as a reinforcing bar with the external thread part 1c by joining by pressure welding etc.

In the case of roll forming as described above, the reinforcing bar 1 constituting the reinforcing bar joint may have a large-diameter portion W1d remaining in the middle, as in the case of FIGS. 7A and 7B. . Since the diameter of the forming roll 11 (FIG. 12) in FIG. 5 is limited, when the reinforcing bar 1 is longer than the peripheral length of the forming roll 11, the large diameter portion W1d remains in the middle. FIG. 12A shows an example in which a reinforcing bar 1 having two continuous large-diameter portions W1d that are twice as long as one male screw portion 1c is provided in the middle, and is cut at the center of the large-diameter portion W1d. And can be used to form the male screw portion 1c. FIG. 12B shows an example in which a large-diameter portion W1d having the same length as the male screw portion 1c is provided in the middle. In any case, since the lock nut 3 is provided in the knot upper screw portion 1d, the length of the large-diameter portion W1d remaining in the middle is short, and the decrease in fixing force to the concrete due to the formation of the large-diameter portion W1d is alleviated. The The enlarged diameter portion W1d is preferably provided with a node portion 1ba ′ as shown in FIGS. 12A and 12B in one or a plurality of locations in the axial direction of the outer peripheral surface. Fixing power is improved.

The knot portion 1ba ′ is formed during roll forming by the forming roll 11. The height of the node 1ba ′ may be the same as the outermost diameter D2 of the reinforcing bar which is the outer diameter of the node 1ba, or may be formed higher or lower than this. When making it higher than the outermost diameter D2 of a reinforcing bar, it is set as the height which does not cause trouble at the time of roll forming. The node portion 1ba ′ of the large diameter portion W1d at the end portion is not crushed when the male screw portion 1c is rolled, but rolling may be performed after the large diameter portion W1d is processed into a perfect circle. The node portion 1ba ′ of the large diameter portion W1d is not necessarily provided. In the example of FIGS. 12A and 12B, in the large diameter portion W1d, the rib 1bb is not formed and the node portion 1ba ′ is interrupted at the circumferential position of the rib 1bb for convenience of roll forming. Although it is a specification, it is good also as a specification with which rib 1bb exists even if it is a specification with which node part 1ba 'continues in a perimeter also in large diameter part W1d.

In the above embodiment, both the reinforcing bars 1 and 1 connected to the coupler have the male screw portion 1c in the large diameter portion W1d and the nodal screw portion 1d in the general portion. The reinforcing bar 1 does not necessarily have the large-diameter portion W1d. For example, the male screw portion 1c is processed into a round shaft having a large diameter as a whole, and the male screw portion 1c is elongated to provide the lock nut 3. May be.
In the above-described embodiment, the lock nuts 3 are provided on both sides of the coupler 2. However, if the lock nut 3 can control the slip amount even with one of the couplers 2, the lock nut 3 may be provided only on one side.

As described above, the preferred embodiments have been described with reference to the drawings, but various additions, changes, or deletions can be made without departing from the spirit of the present invention. Therefore, such a thing is also included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Rebar 1a ... Reinforcing bar main body 1b ... Projection 1ba ... Node 1bb ... Rib 1c ... Male thread 1d ... Projection upper thread 2 ... Coupler 2a ... Female thread 3 ... Lock nut 3a ... Female thread D2 ... Outside of projection Diameter D5 ... Coupler inner diameter h ... No ridge section

Claims (11)

1. A rebar joint for connecting a pair of reinforcing bars, having a male threaded portion at opposite ends of a pair of rebars connected to each other, and including a cylindrical coupler that is screwed into the male threaded part of both reinforcing bars,
   Of the pair of reinforcing bars, at least one of the reinforcing bars is a deformed reinforcing bar having a protrusion on the outer periphery of the reinforcing bar main body, and the male thread portion of the at least one reinforcing bar that is the deformed reinforcing bar has a diameter larger than that of the reinforcing bar main body. A thread groove is formed in the large diameter part of
   A ridge that forms a thread groove on the ridge and allows at least a part of the coupler to escape in a state where the thread and the thread groove are fitted to the reinforcing bar in which the thread groove is formed on the large diameter portion. Provide an upper thread,
   A threaded reinforcing bar joint for deformed reinforcing bars, comprising a lock nut that is screwed into one or both of the male threaded part and the upper threaded part of the ridge and presses the coupler.
2. The threaded reinforcing bar joint of the deformed reinforcing bar according to claim 1, wherein the lock nut is entirely screwed into the male threaded portion, and an inner diameter that is a thread diameter of the female threaded portion of the coupler and the lock nut is equal to that of the reinforcing bar. The outer diameter of the ridge is smaller than the outer diameter of the ridge, and the upper thread portion of the ridge can release the entire lock nut and at least a part of the coupler to the upper thread portion of the ridge when connecting the threaded reinforcing bar joint. Threaded rebar joint of deformed rebar with various lengths.
3. 2. The threaded reinforcing bar joint of deformed reinforcing bars according to claim 1, wherein an intermediate surplus length is provided in the coupler that gives an allowable empty dimension between the end surfaces of the pair of reinforcing bars, and the male threaded part of the reinforcing bar and the upper threaded thread part of the protrusion Between the protrusions, a protrusion-free section that does not have a protrusion extending in the circumferential direction or the spiral direction is provided, and the end face on the anti-coupler side of the lock nut is positioned in the protrusion-free section The male screw portion and the coupler have an appropriate screwing depth so that at least a set fastening length is screwed into the coupler and a screwing state in which the allowable empty dimension is obtained is obtained. , The lock nut, and the threaded reinforcing bar joint of the deformed reinforcing bar in which the relationship of the length of the intermediate surplus length is set.
4. The threaded reinforcing bar joint of deformed reinforcing bars according to claim 3, wherein both of the pair of reinforcing bars are the deformed reinforcing bars, and have the male threaded portion in which a thread groove is formed in the large diameter portion, and Both rebars have the upper threaded portion of the ridge, and both reinforced bars have the appropriate threading depth when the end face on the anti-coupler side of the lock nut is located in the section without the ridge. Reinforcing bar joint.
5. The threaded reinforcing bar joint of a deformed reinforcing bar according to claim 1, wherein a part or the whole of the lock nut is screwed to the upper thread portion of the protrusion.
6. The threaded reinforcing bar joint of deformed reinforcing bars according to claim 5, wherein both of the pair of reinforcing bars are the deformed reinforcing bars, and the male thread portion is formed on the large diameter portion of both the reinforcing bars, and the protrusion A threaded reinforcing bar joint of a deformed reinforcing bar provided with an upper thread portion and the lock nut.
7. 7. The threaded reinforcing bar joint of a deformed reinforcing bar according to claim 5 or claim 6, wherein the lock nut has a length in which 2 to 4 threads of the upper thread portion of the protrusion mesh with each other in a cross section along the axial direction. Threaded rebar joint of deformed rebar.
8. The threaded reinforcing bar joint of the deformed reinforcing bar according to any one of claims 1 to 7, wherein the upper thread portion of the protrusion has a groove bottom diameter smaller than an outer peripheral surface of the reinforcing bar body, and the protrusion A threaded reinforcing bar joint of a deformed reinforcing bar in which the thread groove bottom part of the upper thread part is formed in the reinforcing bar main body.
9. The threaded reinforcing bar joint of a deformed reinforcing bar according to any one of claims 1 to 8, wherein the deformed reinforcing bar has a rib extending in a longitudinal direction, and the upper thread portion of the ridge is also formed on the rib. Threaded reinforcing bar joint of deformed reinforcing bar with thread groove.
10. The threaded reinforcing bar joint of a deformed reinforcing bar according to any one of claims 1 to 9, wherein the deformed reinforcing bar has an outer diameter of the large diameter portion including the protrusions of the deformed reinforcing bar. The following are threaded rebar joints with deformed bars.
11. The threaded reinforcing bar joint of deformed reinforcing bars according to any one of claims 1 to 10, wherein each reinforcing bar is formed by roll molding of a steel wire rod as a raw material, and the protrusion and the large diameter portion are formed. A threaded reinforcing bar joint of a deformed reinforcing bar, wherein each male threaded part and the upper threaded part of the ridge are rolling screws.

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