TWI787516B - Joint utilizing incomplete thread of male threaded portion - Google Patents

Abstract

Provided is a joint for connecting a pair of reinforcing bars (1, 1) with a tubular coupler (2) screwed to male threaded portions (1c) provided on end portions of the reinforcing bars. One reinforcing bar (1) of the pair of reinforcing bars (1, 1) is configured to be deeply screwed until thread ridges of female threaded portion (2a) of the coupler (2) bite into thread grooves of an incomplete thread (1ca) on a proximal end of the male threaded portion (1c) on the reinforcing bar (1) so as to cause at least elastic deformation. By so doing, tightening torque is generated between the male threaded portion (1c) and the coupler (2). An incomplete thread (1ca), which is not generally used, is utilized to generate tightening torque between the male threaded portion (1c) and the coupler (2), and therefore, it is possible to eliminate necessity to secure a length for screwing a locknut etc. on a male threaded portion (1c) on at least one of the reinforcing bars (1).

Description

A joint that utilizes the incomplete thread portion of the external thread portion

The present invention relates to, for example, a joint utilizing an incomplete thread portion of an external thread portion of reinforced concrete.

In reinforced concrete, special-shaped steel bars are generally used for main reinforcement, and special-shaped steel bars or round steel are used for belt bars or stirrups. In long columns, beams, foundations, etc., various reinforcement joints are used in order to perform continuous reinforcement on site with a limited length of reinforcement. Among various steel bar joints, a threaded joint that can be performed in a short period of time is proposed. As shown in FIG. 16, it is described that, as a conventional threaded joint, locknuts 52 are used on both sides of a connector 50 constituted by a threaded cylinder through washers 51 (for example, Patent Document 1). [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Laid-Open No. 10-61107 [Patent Document 2] Japanese Patent Laid-Open No. 2008-063730

In addition to tensile loads, steel joints can also withstand predetermined compressive loads, which are determined on the basis of construction. In the threaded steel bar joint, there is a problem that the clearance at the portion where the external thread portion of the steel bar engages with the internal thread portion of the threaded cylinder is sufficient to require a compressive load. That is, the engaging portion of the screw thread is provided with a predetermined clearance, that is, a backlash, so that the locking operation can be performed. Therefore, when the load state of the tensile load is changed to the load state of the compressive load, the crest of the female thread part that pushes the crest of the male thread part on one side of the crest moves only by the amount of clearance, and becomes the same as that of the push male thread part. The surface on the opposite side of the adjacent screw top. The movement of the female thread portion within this clearance is free movement, which poses a problem in compliance with the regulations on the sliding amount. As the diameter of the steel bar increases, the clearance also increases, making the above-mentioned problems even greater.

The problem with this clearance is that it can be eliminated by using a lock nut. However, the threaded steel bar joint using the known anti-loosening nut is provided with an external thread portion across a range where the connector and the anti-loosening nut can be disengaged in advance for connection work. Therefore, the length of the male thread portion is increased.

When the length of the male thread portion of the reinforcing bar becomes longer, the following problems arise. Due to the common use of materials, the special-shaped steel bar constituting the threaded steel bar joint may not be used as the threaded steel bar joint, but may be embedded in reinforced concrete in the same way as ordinary special-shaped steel bars. At this time, in the length range of the external thread portion, especially in the case of a special-shaped steel bar, the characteristic knot portion has a weak anchoring force with respect to concrete. Therefore, it is difficult to use a steel bar provided with an external thread portion as a special-shaped steel bar. The regulation of special-shaped steel bars in building standards is within the range of the steel bar length relative to the predetermined multiple of the steel bar diameter, which can be determined according to how many nodes must be there. When implementing this regulation with a deformed steel bar having an externally threaded portion of a detachable length for a locknut, the joints of the nodes at portions other than the externally threaded portion will be shortened, resulting in an increase in cost. When the special-shaped steel bar with the external thread part is not handled as a general special-shaped steel bar, it will be complicated in management and in the storage and handling of the steel bar on site.

In addition, the range for preliminarily disengaging the connector and the lock nut on the external thread part is exposed by locking the connector or the lock nut. Since the exposed portion of the outer thread does not have a knot, there is a problem that the anchoring force is weak.

In addition, once the length of the external thread portion becomes longer, depending on the amount, the tools for thread processing, such as rolling will cause dies and cutting tools to wear more, and the wear of this tool will lead to a reduction in life. It is one of the biggest factors that increase the cost of steel bar joints. Also known threaded steel bar joints with lock nuts are shown in Figure 16, at the connector 50 Locking nuts 52 are respectively provided on both sides through washers 51, thus increasing the number of parts and components and increasing the cost. Problems such as the reduction in the life of threading and the increase in the number of parts due to gaskets are also the same in the case of round steel.

The object of the present invention is to provide a joint that utilizes the incomplete thread part of the external thread part that can meet the requirements of both the tensile force resistance and the compression force resistance, and can improve the versatility, and reduce the number of parts to obtain cost reduction. .

The joint utilizing the incomplete thread portion of the external thread portion related to the first configuration of the present invention is to connect a pair of steel bars with a cylindrical connector screwed to the external thread portion provided at the ends of the two steel bars. There is no intervening joint between the outer peripheral surface of the threaded part and the inner peripheral surface of the above-mentioned connector, and any one or both of the steel bars in the above-mentioned pair of steel bars is the screw top of the internal thread part of the above-mentioned connector by at least bit into the elastically deformed state and screwed deeply to the screw groove of the incomplete threaded portion at the base end of the externally threaded portion of the steel bar, thereby generating an anti-loosening torque between the externally threaded portion and the connector, and the externally threaded portion The complete thread portion of the thread portion produces an axial clearance between the crest of the internal thread portion and the crest of the external thread portion.

When the external thread is formed at the end of the steel bar, the screw grooves are sequentially formed at the boundary between the cylindrical part and the complete thread and at the front end of the thread by means of the chamfer or reverse taper of the tool for processing the external thread. Shallow, that is, the so-called incomplete thread. In a general threaded steel bar joint, the incomplete thread portion at the base end of the external thread portion ensures a long external thread portion so as not to engage with each internal thread portion of the threaded barrel and lock nut.

According to the first configuration of the present invention, the common sense of avoiding the screwing of the incomplete threaded part is broken, and the screw top of the female threaded part of the connector is screwed to any of them at least bit into the depth of the elastic deformation state. The screw groove of the incomplete thread part at the base end of the external thread part of one steel bar. Thereby, an anti-loosening torque is generated between the male thread part and the connector. In addition, when the tensile force and the compressive force act on the steel bar joint, the contact surface of the screw tops of the external thread part and the internal thread part will not change, and the contact surface between the external thread part and the internal thread part will not change. Small clearance can solve the problem of large clearance.

In addition, a part of the crest of the internal thread portion of the connector can be plastically deformed and screwed to the groove of the incomplete thread portion. The anti-loosening torque is given to the steel bar, so that when the tensile force acts on the steel bars on both sides, the screw tops that are in contact with each other maintain contact with each other to generate backlash (backlash), and the tensile force proceeds from one side of the steel bar → connector → the other Passing of the reinforcement on one side. When the compressive force acts on the steel bars on both sides, the compressive force is transmitted from the groove of the incomplete thread part of the steel bar to the screw crest of the internal thread part of the connector biting into the screw groove in an elastic deformation state. Therefore, both requirements of tensile resistance and compression resistance can be satisfied.

As mentioned above, the incomplete thread part may be produced during manufacture, but generally the unused incomplete thread part is used to generate an anti-loosening torque between the external thread part and the connector during screw locking. Therefore, it is not necessary to secure a length for screwing a lock nut or the like to at least one of the male threaded portions of the reinforcing bar. In other words, the external thread portion of the reinforcing bar may be of a length sufficient to be screwed to the internal thread portion of the connector. In this way, the same anti-loosening function as that of the anti-loosening nut can be obtained, and the length of the external thread portion and the axial length of the connector can be shortened compared with the conventional threaded steel bar joint with the anti-loosening nut. Therefore, it is possible to reduce the material cost of the connector in addition to eliminating the need to shorten portions other than the male thread portion (for example, intervals between pitch portions, etc.). As a result, the acquisition cost is reduced.

In addition, special-shaped steel bars with external threads can be used as general special-shaped steel bars, improving versatility. In addition, compared with the conventional threaded steel joint, the anti-loosening nut and the like can be reduced, so compared with the conventional structure, the number of parts and components can be reduced and the cost can be reduced.

It is also possible to arrange two steel bars so that the front ends of the opposite external thread parts in the connector contact each other. At this time, when the compressive force acts on the steel bars on both sides, the compressive force is transmitted from the screw top of the incomplete thread part of the steel bar to the screw top of the internal thread part of the connector that bites into the screw groove at least in an elastically deformed state, and passes through The tip of the male thread is transmitted to the other reinforcing bar. Thereby, the requirements for resistance to compressive force can be satisfied.

For any one of the above-mentioned pair of steel bars, it is also possible to make the above-mentioned screw top of the above-mentioned connector bite into the screw groove of the above-mentioned incomplete thread portion at least in an elastically deformed state, and screw the anti-loosening nut to any one of the other steel bars. The external thread part of the square steel bar.

Although the present invention secures its performance by introducing the anti-loosening torque into the reinforcing bar, there is a possibility that it may adversely affect other reinforcing bar joints after the work is completed. For this reason, according to this structure, the anti-loosening nut is provided on one side of the reinforcing bar, and it is possible to prevent adverse effects on other reinforcing bar joints after the work is completed. For a pair of steel bars, steel bars with different lengths of the external thread portion are prepared in advance, and for the steel bar with the shorter length of the external thread portion, the screw top of the internal thread portion of the coupler is screwed at least as deeply as it bites into the elastically deformed state. The screw groove of the incomplete thread part at the base end of the external thread part. In this way, the anti-loosening torque between the external thread part and the connector can be determined.

The determined anti-loosening torque is a torque that can be set arbitrarily according to the design, for example, it can be set by obtaining an appropriate torque through either or both of tests and simulations. Thereafter, a predetermined tightening torque is applied to the other reinforcing bar screwed to the external thread length. If the anti-loosening nut is set on one side of the steel bar as above, it can prevent adverse effects on other steel bar joints after the work is completed.

A tightening length confirmation hole for confirming that the pair of steel bars are locked into the coupler by a predetermined minimum tightening length may be formed in the coupler. There is only one confirmation hole, but a plurality of holes may be provided. In addition, the position where the fastening length confirmation hole is provided is only a position where it can be confirmed that the steel bars on both sides are fastened to the minimum length of the coupler, and it does not necessarily have to be at the center of the coupler in the longitudinal direction. The predetermined minimum length of fastening can be suitably designed. When setting the confirmation hole, by peeping into the confirmation hole, inserting the pin-shaped bracket into the confirmation hole or letting light pass through the confirmation hole, it is easy to confirm whether the steel bar is locked to the minimum length of fastening.

In the first configuration of the present invention, one or both of the above-mentioned pair of steel bars may have a plurality of knots at intervals in the longitudinal direction on the periphery of the circular shaft-shaped steel bar main body, and have a longitudinal direction. Extended profiled bar. According to this configuration, it is possible to meet both the requirements of compressive tension resistance and compression resistance, and to improve versatility.

In the first configuration of the present invention, one or both of the pair of reinforcing bars may be round steel. At this time, the round steel does not have ribs and does not generate cross-sectional defects. In addition, the round steel is produced and supplied in the form of a coil, which is easy to handle at low cost, causes less damage, and has many types of steel, so there are many advantages.

The joint related to the second configuration of the present invention is a steel bar joint that connects the ends of a pair of steel bars facing each other in the longitudinal direction, and includes: a cylindrical body with a female thread part formed on the inner surface; A joint member; a connecting member that displaceably connects a pair of joint members opposite to each other in the longitudinal direction and the direction perpendicular thereto, and is screwed at one end of the cylindrical body with the external threaded part of the steel bar formed at the end of one of the above-mentioned steel bars screwing the joint external thread portion of one end portion of the joint member at the other end, and screwing the top of the internal thread portion of the one end portion of the cylindrical body to the above-mentioned joint at least deeply into the elastically deformed state. The screw groove of the incomplete threaded portion at the base end of the external threaded portion of the steel bar thereby generates an anti-loosening torque between the external threaded portion of the steel bar and the cylindrical body.

As is known, steel bar joints, which are reinforced concrete structures such as beams and columns, are roughly classified into the following four types. That is, lap joints, gas welded joints, welded joints, and mechanical joints. In particular, a mechanical joint is known in which a connector is applied to the end of a steel bar, and the joint of the steel bar and the connector is engaged or the joint of the thread is used to integrate the steel bar. The advantages of this mechanical joint include, for example, that the steel bars will not shrink during construction; all component ends can be jointed; the operator does not need special qualifications; and it is not affected by the weather.

In addition to the above four types of steel bar joints, a method of joining steel bars using expensive slurry materials (mortar, cement slurry, synthetic resin, etc.) may also be used (for example, the above-mentioned Patent Document 2).

However, in the case of this slurry type joint, it is difficult to ensure the positional accuracy of the reinforcing bar group. Furthermore, after the injection of the slurry material, it takes considerable time until the slurry material hardens to a predetermined strength. Therefore, the next step cannot be carried out until the slurry hardens, which greatly affects the cost and construction period.

According to the above-mentioned second configuration of the present invention, when joining a pair of steel bar joints in the cylindrical body, it is only necessary to use only screw connection without using an expensive slurry material such as mortar that takes several days to harden. Therefore, reduction of construction cost and shortening of construction period can be achieved. Moreover, the connection member which connects one pair of opposing joint members connects these pairs of joint members so that it can displace in the longitudinal direction and the direction orthogonal to it. Therefore, even if there is some eccentricity between a pair of joint members, that is, there is some eccentricity or longitudinal deviation between a pair of steel bars, the deviation can still be absorbed to connect a pair of joint members, that is, A pair of steel bars for each other. Thereby, it becomes easy to ensure the positional accuracy as a reinforcement group. As described above, even if the connection of a pair of steel bars is within a certain allowable range, the construction period can be shortened.

Similar to the first configuration, the top of the female threaded portion of the connector is screwed to the groove of the incomplete threaded portion at the base end of the external threaded portion of any one of the reinforcing bars at least bit into the elastically deformed state. Thereby, an anti-loosening torque is generated between the male thread part and the connector. When the tensile force and compressive force are applied to the steel bar joint, the contact surfaces of the tops of the male threaded part and the female threaded part will not change, and the clearance between the male threaded part and the female threaded part will not change. It is small and can solve the problem of increased clearance.

In this case, the joint member may have a main body portion and the joint external thread portion, and the connecting member and the joint member may be detachably connected by a fastening member in a state where the main bodies of the pair of joint members face each other in the longitudinal direction. According to this configuration, not only reinforcement assembly in a factory but also reinforcement assembly at a construction site can be quickly and easily performed.

In this case, it is preferable that the main body part of the said joint member is interposed between a pair of said connection members. According to this configuration, since the main body portion of the joint member is firmly held in the sandwich structure by the pair of connecting members, the reliability of joining the pair of reinforcing bars can also be improved.

In addition, in the reinforced concrete body of the present invention, the cylindrical body and the steel bar of the joint of the present invention are embedded in concrete, and the female thread portion of the cylindrical body is exposed from the end surface of the concrete. According to this structure, the steel reinforced concrete body constituting the beam or column in the reinforced concrete structure is manufactured in the factory, and when joining this at the construction site, the external thread portion of the outer end surface of the cylindrical body exposed from the end surface of the concrete is used. , the steel bar joints can easily join adjacent reinforced concrete bodies. Therefore, the workability at the construction site is remarkably improved.

Any combination of at least two structures disclosed in the scope of claims and/or the description and/or drawings is included in the present invention. In particular, any combination of two or more of the claims in the claims is also included in the present invention.

[First Embodiment] A first embodiment of the present invention will be described together with FIGS. 1A to 6B. As shown in Figure 1A, the joint of the incomplete thread part of the external thread part is a threaded steel bar joint of special-shaped steel bar, which has a pair of steel bars 1, 1 and external threads screwed on the ends of the two steel bars 1, 1. The cylindrical connector 2 of the part 1c.

＜For Rebar 1＞ Each reinforcing bar 1 is a deformed reinforcing bar having a protrusion 1b on the outer peripheral surface of a cylindrical bar main body 1a. The protrusion 1b has a node portion 1ba extending in the circumferential direction, and a rib 1bb extending in the longitudinal direction. Two ribs 1bb are provided at positions separated by 180° of the reinforcing bar main body 1a. In this example, the nodes 1ba are alternately arranged on the half circumference with the ribs 1bb as the border. In addition, the node portion 1ba may have a continuous shape over its entire circumference.

The external thread portion of each steel bar 1 is, for example, a rolled thread, and the hardness of at least the surface layer portion is made harder than that of other parts of the steel bar 1 by work hardening (also called plastic hardening). The external threaded part 1c is shown in Fig. 2A and Fig. 2B. In order to improve the precision of the thread processing on the nodal part 1ba and rib 1bb, in addition to processing the perfect circle to the extent that the base ends of the nodal part 1ba and rib 1bb remain , as shown in Figure 2C to apply thread processing. Therefore, the size of the screw top is different at the position where the knot portion 1ba is not provided.

Furthermore, the outer diameter of the rib 1bb is the same as that of the knuckle 1ba. Therefore, considering the axial width of the entire periphery with the joint portion 1ba and the axially wide portion without the joint portion 1ba, the dimensions of the crest of the external thread portion 1c are the same. That is, at the place where the rib 1bb is provided, there is formed a crest of the same size as that of the crest formed on the outer threaded portion 1c of the axially wide portion of the knob portion 1ba. So-called incomplete thread portions 1ca and 1cb in which the screw grooves become shallower in sequence are formed at the boundary portion between the external thread portion 1c and the reinforcing bar main body 1a, and at the front end portion of the thread. The incomplete thread portion 1cb at the front end of the thread is chamfered.

As shown in FIG. 1A, the thread lengths of the left and right male threaded portions 1c are different, and one (left side in FIG. 1A ) of the steel bar 1 is rolled for a length (L1) corresponding to the tightening thread length. The thread length (L1) on the left side is set for each steel bar diameter. The external thread portion 1c of the steel bar 1 on the other side (the right side of Fig. 1A) can meet the performance value of the A-level joint in terms of the specifications of the steel bar joint except for the length of the connector, and does not affect the concrete adhesion of the steel bar 1 Range sets the thread length (L2). This thread length ( L2 ) is set to a length at which the entire connector 2 is detached during, for example, a steel bar fastening operation such as the ironwork method. Specifically, the thread length (L2) is, for example, multiplied by "3" by the connector length, and the connector length is set as the thread length (L1)×2+(5~10mm). For this range (5~10mm), 5mm is used when the steel bar 1 has a thin diameter, and 10mm is used when the diameter is thick.

<for Linker 2>

As shown in FIG. 1A and FIG. 1B , the inner circumference of the connector 2 is formed with an internal thread portion 2 a, and the outer surface is a hexagonal threaded cylinder. It is necessary for the connector 2 to secure only the tightening length required for the tensile strength required for the joint of the steel bar 1 with respect to the external thread portion 1c of the steel bar 1 . In addition, the outer peripheral surface of the connector 2 is not limited to the hexagonal shape, for example, a non-circular portion such as a hexagonal shape or a polygonal shape may be formed on a part or the whole of the cylindrical shape in the axial direction.

As shown in FIG. 1B, in the center of the connector 2, a fastening length confirmation hole 2b of a circular through hole is formed. This fastening length confirming hole 2b can visually see that a pair of steel bars 1, 1 are locked in the connector 2 to the predetermined fastening maximum. Holes of small length. The fastening length confirmation hole 2b is not limited to a circular shape, and a plurality of them may be provided.

It may not be the confirmation hole 2b. In particular, in a connector 2 with a small outer diameter, if the confirmation hole 2b of a visually sized size is provided, the strength of the connector 2 may be greatly affected, so the confirmation hole 2b may be omitted. At this time, the thread lengths L1 and L2 of the external threaded portion 1c of the two steel bars 1 and 1 are known in advance, so the locking amount of the left external threaded portion 1c to the connector 2 is L1. On the other hand, the locking amount of the right external thread portion 1c can be obtained by measuring the exposed length L0 of the connector 2 from the external thread portion 1c (=L2-L0).

The thread length (L1) of the externally threaded portion 1c of the steel bar 1 on one side (the left side in FIG. 1A) is processed to be the same length as the fastening length at the time of manufacture, and the other side (the right side in FIG. 1A ) is arranged so that ) The front end portion of the steel bar 1 contacts the front end portion of the one steel bar 1 . Therefore, both parties can confirm locking to the predetermined minimum fastening length from one confirmation hole 2b. In addition, although not shown, chamfering may be provided on the inner peripheral edge portions of both axial ends of the connector 2 . By setting the chamfer, the screwing of the steel bar 1 to the external thread portion 1c becomes smooth, and the workability can be improved.

As shown in Fig. 3A and Fig. 3D, one side (the left side of Fig. 1A) of the steel bar 1 is screwed with the screw top 2aa of the internal thread part 2a of the connector 2 at least to the depth of the elastic deformation state. The screw groove of the incomplete threaded portion 1ca at the base end of the externally threaded portion 1c of 1, thereby generating an anti-loosening torque between the externally threaded portion 1c and the connector 2. Rotate the connector 2 in the state of being screwed to the steel bar 1, so that both sides of the flange of the incomplete threaded portion 1ca at the base end of the external threaded portion 1c contact the screw top 2aa of the internal threaded portion 2a respectively. And rotate the connector 2 to eliminate the vibration between the outer threaded part 1c and the inner threaded part 2a of the steel bar 1 due to the anti-loosening torque.

As shown in Figures 3A to 3D, the internal thread portion 2a of the connector 2 is a complete thread across the axial direction. The external thread part 1c is a complete thread from the center of the connector 2 shown in Figure 3B (including the thread that can be engaged with the top part of the screw cap missing). The vicinity of the base end of the portion 1c becomes shallower sequentially. In addition, as shown in FIG. 3D, at the base end of the externally threaded portion 1c, both sides of the flange of the incomplete threaded portion 1ca are in contact with the crests 2aa of the internally threaded portion 2a, respectively. As shown in Figure 3D, the centers of the external thread portion 1c and the internal thread portion 2a are completely coincident with the incomplete thread portion 1ca, so that the external thread portion 1c and the internal thread portion 2a of the complete thread portion shown in Figure 3B are pointed The axial gap δ becomes tiny. This axial play δ can be determined explicitly by calculation.

In addition, in Figs. 3B to 3D, trapezoidal threads are formed for easy understanding of the relationship between the internal thread portion 2a and the external thread portion 1c, but the first embodiment employs a triangular thread. As shown in FIG. 1A, the other steel bar 1 is arranged in a state where the outer threaded part 1c is screwed to the connector 2 so that the front ends of the outer threaded part 1c of the two steel bars 1 and 1 are in contact with each other. Apply tightening torque to complete the tightening work. Moreover, the front-end|tip part of the external thread part 1c of both reinforcement bars 1 and 1 may be separated from each other.

＜Concrete example of fastening work＞ As shown in FIG. 4A, one side (the left side of FIG. 4A ) of the steel bar 1 is processed so that the thread length of the external thread portion 1c can be recognized from the fastening length confirmation hole 2b, in other words, the thread length overlaps with the confirmation hole 2b. First, with the connector 2 screwed to the male threaded portion 1c of the other (right side in FIG. 4A ) reinforcing bar 1 , the ends of the externally threaded portion 1c of the two rebars 1 and 1 are brought into contact with each other. Next, the rotary coupling 2 moves from the other reinforcing bar side toward the one reinforcing bar side. The connector 2 is stopped in a state where the connector 2 is screwed to both the external thread portions 1c, 1c.

As shown in FIG. 4B, after the first mark M1 in the connection axial direction is applied to the reinforcing bar 1 and the connector 2 across one side (the left side of FIG. 4B ), torque is applied to the connector 2 . As shown in FIG. 4C, torque is applied to the coupling 2, whereby a circumferential displacement δ1 is generated between the reinforcing bar 1 and the coupling 2 on one side (the left side in FIG. 4B). Screw the screw top 2aa (refer to Figure 3D) of the internal thread portion 2a of the connector 2 to the incomplete thread portion 1ca of the base end of the external thread portion 1c of the steel bar 1 at least bit into the elastic deformation state (refer to Figure 3D) of the screw groove. Here, the reinforcing bar 1 and the coupling 2 straddling one side (the left side in FIG. 4B ) are further given the second mark M2 in the connection axial direction.

As shown in Fig. 4D, then, the steel bar 1 on the other side (the right side of Fig. 4D) is further rotated, so that the other side (Fig. On the right side) the steel bar 1 and the connector 2 are given the third mark M3 in the connection axis. And after torque is given to the other (the right side in FIG. 4D ) steel bar 1 , the fourth mark M4 for connecting the axial direction is further applied across the steel bar 1 and the coupler 2 .

In the example of this fastening work, a torque is introduced between a pair of steel bars 1, 1 and the connector 2, and it is inevitable to visually confirm that the two steel bars 1, 1 are locked to the predetermined fastening length through the fastening length confirmation hole 2b. Minimum length. It can be seen that when excessive force is applied during the tightening work of other joints in succession, and the torque disappears, as long as the second and fourth marks M2 and M4 are displaced, it is necessary to apply torque again. .

By imparting anti-loosening torque to the reinforcement 1, when a tensile force is generated on the reinforcement 1, 1 on both sides (indicated by a solid arrow in FIG. 1B), the tiny gap immediately contacts and smooth force transmission is performed. The length in the circumferential direction of the lock in FIG. 3D is also less than a few percentages compared with the circumferential length of the entire thread (the length in the circumferential direction of all the external thread parts 1c connecting the helix from the axial front end of the external thread part 1c to the base end), And caused this action. As shown in FIG. 3D, the tensile force is transmitted from the surface 1ca of the screw top of the external thread portion 1c of the steel bar 1 in contact with the connector 2 to the screw top 2aa of the internal thread portion 2a of the connector 2. Therefore, the tensile force is transmitted from one reinforcing bar 1 to the coupling 2 to the other reinforcing bar 1 .

When a compressive force (shown by a dotted arrow in FIG. 1B ) acts on the steel bars 1 and 1 on both sides, the compressive force is transmitted from the screw groove of the incomplete thread portion 1ca of the steel bar 1 to bite into the screw in at least an elastically deformed state. The screw top 2aa of the internal thread part 2a of the groove connector 2 (Fig. 3D), and most of them are transmitted to the other steel bar 1 through the front end of the external thread part 1c. In addition, the compressive force required for the steel joint is half that of the yield point strength, which is sufficient.

＜Manufacturing method of steel bar 1＞ As shown in FIG. 2A, the steel bar 1 used as the raw material of the special-shaped steel bar is cut to a desired arbitrary length at a construction site or a factory. As shown in FIG. 2B, the end portion of the steel bar 1 after cutting is processed into a perfect circle in the length range of the external thread portion 1c. In this perfect circle processing, the outer diameter D5 is cut into a perfect circle such that the base end of the protrusion 1b having the node portion 1ba and the rib 1bb of the steel bar 1 remains, or the base end is substantially eliminated. The node portion 1ba is formed into a portion 1baa with a low protruding height by perfect circle processing. The outer diameter D5 is slightly larger than the outer diameter D1 of the reinforcing bar 1a. Since there is a slight change in diameter accompanying threading, the outer diameter D5 is different from the crest diameter of the external thread portion 1c (FIG. 2C). In addition, the outer diameter D5 may be the same as or slightly smaller than the outer diameter D1 of the reinforcing bar main body 1a.

As shown in FIG. 2C, the portion of the steel bar 1 that has been subjected to perfect round processing is formed by rolling an external thread portion 1c. The portion subjected to perfect circular processing is processed by rolling between a pair of rolling rolls 13, 13 shown in FIG. 5, and an external thread portion 1c is formed (FIG. 2C). Thereby, it becomes the steel bar which has the external thread part 1c (FIG. 2C) at the end part. The pair of rolls 13 and 13 for rolling are arranged apart from each other, and the portion subjected to perfect circular processing is positioned between the rolls 13 and 13 for rolling. Thereafter, both rolling rolls 13 and 13 are moved radially as indicated by the arrows while being rotated to press against the portion subjected to the perfect circle processing, and the external thread portion 1c (FIG. 2C) is processed. The processing of the external thread portion 1c is not limited to rolling, but may be cutting.

＜For anchor plates, etc.＞ As shown in Fig. 11, the threaded anchor disc 61 is used as the overall system of the steel bar joint. In the overall system, the combination: the external thread part of the short thread length (L1); the external thread part of the long thread length (L2) is screwed to the joint pattern A of the connector 2; and the long thread length (L2) The external thread parts are screwed to the joint pattern B of the connector 2 . On both outermost ends of the overall system provided with this anchor disc 61, for example, an external thread portion 1c of a short thread length (L1) (FIG. 1A) is arranged.

As shown in FIG. 6A, the anchor plate 61 is formed of a plate shape having a screw hole 61h for imparting an anchoring force, and a rectangular portion 61a and a circular portion 61b are integrally formed in the axial direction. The outer periphery of the rectangular portion 61 a is formed of a hexagonal shape, and the anchoring disc 61 can be screwed to the external threaded portion 1 c by means of a tool or the like. One side surface of the circular portion 61b connected to the rectangular portion 61a has an oblique tapered shape inclined toward one end side in the axial direction as it goes radially outward.

As shown in FIG. 6B, the anchor plate 61A may include a cylindrical portion 61Aa having a screw hole 61h, and an annular ring portion 61Ab fitted into the cylindrical portion 61Aa. The cylindrical portion 61Aa has, for example, a rectangular portion 62 whose periphery is formed in a hexagonal shape, and a tapered portion 63 integrally formed on one side of the rectangular portion 62 . The tapered portion 63 has a tapered shape that expands in diameter from the distal end toward the proximal end. A cylindrical hole 64 is formed in the annular portion 61Ab, and the tapered portion 63 is fitted into the cylindrical hole 64 .

For example, when embedding a steel bar serving as a concrete part of a beam into a concrete part serving as a column, the end of the bar is bent into a U-shape or L-shape and embedded in order to ensure anchorage in the column. However, when there are many curved portions of the above-mentioned steel bar, the reinforcement in the column becomes complicated. For this reason, the diameter-enlarged head that forms the diameter-expanded end of the steel bar replaces the U-shaped or L-shaped bent portion to secure the anchoring force. However, the known expanding head is manufactured by thermally plastically deforming the end of the steel bar by means of high-frequency induction, etc., so the manufacturing process requires equipment and labor time. To solve this problem, in this example, the anchor plate 61 of FIG. 6A and the anchor plate 61A of FIG. 6B are screwed together to form an enlarged head at the end of the steel bar 1 after diameter expansion. In this case, the diameter-enlarging head can be easily formed without requiring special equipment and without consuming man-hours.

＜Aiming at the effect＞ When forming the external threaded part 1c at the end of the steel bar 1, by the chamfering or biting part of the tool for processing the external threaded part 1c, at the boundary between the cylindrical part and the complete threaded part (the base end of the external threaded part 1c) And the front end of the thread produces the so-called incomplete thread part in which the screw groove becomes shallower in sequence. In a general threaded steel bar joint, the incomplete thread portion at the base end of the external thread portion is set to be long so as not to engage with the internal thread portions of the threaded barrel and lock nut.

According to the joint of the incomplete thread part of the external thread part of this embodiment, the screw groove of the incomplete thread part 1ca at the base end of the external thread part 1c of any one of the steel bars 1 is used to connect the inner part of the connector 2 The crest 2aa of the threaded portion 2a is screwed at least to a depth of biting into an elastically deformed state. Thereby, an anti-loosening torque is generated between the external thread part 1c and the coupling 2. As shown in FIG. Also, when the tensile force and the compressive force act on the steel bar joint, the contact surfaces of the screw tops of the external thread portion 1c and the internal thread portion 2a are not changed, and the external thread portion 1c and the internal thread are eliminated. The problem of the play between the parts 2a. By imparting the anti-loosening torque to the steel bar 1, when the tensile force is generated on the steel bars 1 and 1 on both sides, the tiny gap can be brought into contact immediately, and the force can be transmitted smoothly.

The length of the lock in Figure 3D failed to reach a few percent compared to the circumference of the full thread to cause such a move. Tensile force is transmitted from one reinforcing bar 1 to the coupling 2 to the other reinforcing bar 2 . When the compressive force acts on the steel bars 1 and 1 on both sides, the compressive force is at least transmitted from the screw groove of the incomplete threaded part 1ca of the steel bar 1 to the internal threaded part of the connector 2 biting into the screw groove at least in an elastically deformed state 2a, most of which are transmitted to the other steel bar 1 through the front end of the external threaded portion 1c. Therefore, both requirements of tensile resistance and compression resistance can be satisfied.

As described above, the incomplete threaded portion 1ca, which is generally not used, produces a loosening preventing torque between the external threaded portion 1c and the connector 2, although it may occur during manufacture. Therefore, there is no need to secure a length for screwing a lock nut or the like to at least one of the male thread portions 1c of the reinforcing bar 1 . In other words, the male threaded portion 1c of the steel bar 1 only needs to have a length sufficient to be screwed to the female threaded portion 2a of the connector 2 . Thereby, the length of the external thread portion 1c and the axial length of the connector 2 can be shortened compared with conventional threaded steel bar joints. Therefore, it is not necessary to shorten the parts other than the male threaded part (for example, the interval between the knot parts 1ba, etc.), and the material cost of the connector 2 can also be reduced. As a result, cost reduction can be achieved.

In addition, the special-shaped steel bar with the external thread part can be used as a general special-shaped steel bar, and the versatility can be improved. Moreover, compared with the conventional threaded steel bar joint with lock nuts, the number of lock nuts and the like can be reduced, and the cost can be reduced by reducing the number of parts and components compared with conventional structures.

[For other embodiments] In the following description, the same reference numerals are assigned to the parts corresponding to the matters previously described in the respective embodiments, and overlapping descriptions are omitted. When only a part of the configuration is described, other parts of the configuration are the same as those described above unless otherwise specified. The same effect can be realized by the same composition. In addition to the combination of parts specifically described in the respective embodiments, the embodiments may be partially combined as long as there is no problem in combination.

[Example where left and right thread lengths are the same] As in the second embodiment of Fig. 7, the thread lengths of the external threaded parts 1c of the left and right steel bars 1 and 1 can also be set to be the same, and the screw grooves of the incomplete threaded parts 1ca at the base ends of each external threaded part 1c are respectively screwed together to make The crest of the female thread portion 2 a of the connector 2 bites into the depth at least to the elastically deformed state. The two reinforcing bars 1, 1 are screwed to the connector 2 with a predetermined interval therebetween so that the front ends of the externally threaded portion 1c are not in contact with each other. At this time, a torque equivalent to a normal torque value is applied to each steel bar 1 , and the specification of the steel bar joint is a class A joint or higher. The two steel bars 1, 1 are fastened to the connector 2 before shipment from the factory or on site. With this configuration, the length of the external threaded portion 1c of the two steel bars 1 and 1 can be shortened, further reducing the number of components such as lock nuts to reduce costs. In addition, the same operational effects as those of the above-described embodiment are achieved.

[Example of changing left and right thread length] As in the third embodiment shown in FIG. 8, the screw top of the connector 2 can also be bitten into the screw groove of the incomplete threaded portion 1ca of the steel bar 1 on one side (the left side in FIG. 8 ) at least in an elastically deformed state, and The external thread portion 1c of the reinforcing bar 1 on the other side (the right side in FIG. 8 ) is screwed to the anti-loosening nut 15 through the washer 14 . However, the gasket 14 may also be omitted. When the anti-loosening nut is introduced into the steel bar to ensure the performance, it will have an adverse effect on other steel bar joints after the work is completed.

For this reason, according to the structure of Fig. 8, locknut 15 is set on the one side of reinforcing bar 1, can prevent other reinforcing bar joints that work finishes from causing bad influence before it happens. The external thread part 1c of a different length is prepared beforehand with respect to a pair of reinforcement bar 1,1. The thread length of the steel bar 1 on the other side (the right side in Fig. 8) with the longer external thread portion 1c is as long as the coupling 2, locknut 15, and washer 14 (including the protruding part. If there is no washer 14, it is as short as the washer 14 Thickness.) The sum of the axial lengths is sufficient, but in this example, ensure 1.7 times this length. 0.7 times the amount is not needed in the work, it is used to adjust the length, and can be cut by a high-speed shear or a round-head knife shear.

For the steel bar 1 with the shorter length of the external thread portion 1c (the left side in FIG. 8 ), the screw top of the internal thread portion 2a of the coupler 2 is placed in the screw groove of the incomplete thread portion 1ca at the base end of the external thread portion 1c. At least the depth of screwing up to the state of elastic deformation. Thereby, the anti-loosening torque determined between the external thread part 1c and the coupling 2 is obtained. Thereafter, a predetermined tightening torque is applied to the locknut 15 screwed to the reinforcing bar 1 on the other side (the right side in FIG. 8 ) with the longer external thread portion 1c. As mentioned above, the anti-loosening nut 15 is provided on one side of the steel bar 1, 1, which can prevent adverse effects on other steel bar joints after the work is completed.

[Joint for connecting] As in the fourth embodiment shown in FIG. 9, a steel bar joint in which the front ends of the two steel bars 1 and 1 are in contact with each other to impart torque may be embedded in concrete 16 and screwed to the external threaded portion 1c of the exposed steel bar 1. Lock nut 15. In this case, since there is no need to provide the fastening length confirmation hole in the connector 2, the processing cost can be reduced.

[Joint including length adjustment] As in the fifth embodiment shown in Fig. 10, it is also possible to screw the anti-loosening nut 15 on the external thread portion 1c of the steel bar 1 on the right side of Fig. 10, thereby ensuring about twice the standard thread length as the external thread portion 1c The thread length L, this part is cut off on site to adjust the length. The standard thread length L is the sum of the length of the connector and the height of the locknut. In addition, a lock nut 15 may be screwed to the external thread portion 1c of the right steel bar 1 through a washer (not shown). At this time, the washer mainly has the function of torque confirmation.

[Example of using round steel instead of special-shaped steel bar] Like the sixth embodiment shown in Fig. 12, round steel may be used instead of the reinforcing bar (in this case, deformed reinforcing bar) used in the first embodiment shown in Fig. 1 . As shown in Figure 13, which is a partially enlarged view of Figure 12, one side (the left part of Figure 12) of the steel bar 1 is in the same state as that shown in Figures 3A to 3D, that is, the external thread of the steel bar 1 The screw groove of the incomplete threaded part 1ca at the base end of the part 1c is screwed so that the screw crest 2aa of the internal threaded part 2a of the connector 2 bites at least to the depth of the elastically deformed state. Thereby, an anti-loosening torque is generated between the external thread part 1c and the coupling 2. As shown in FIG. In addition, one of the pair of reinforcing bars may be a special-shaped reinforcing bar.

In the seventh embodiment shown in Fig. 14, the external thread portions 1c, 1c of the two steel bars 1, 1 of the round steel are screwed in opposite directions. After the rebars 1, 1 are connected by the connector 2, when the connector 2 is rotated, the two threaded portions 1c, 1c are screwed in opposite directions to each other, so the gap α between the rebars 1, 1 in the connector 2 is changed. Therefore, while adjusting the gap α, the coupling 2 is moved in and out to the vicinity of the incomplete thread portion 1ca of the left round steel 1, and after confirming that an appropriate gap α is obtained, the incomplete thread portion 1ca is further bitten with a large torque. . In the case of using this reverse thread, special-shaped steel bars can also be used instead of round steel.

As mentioned above, when using round steel bars instead of deformed steel bars, there will be no cross-sectional defects because they are not ribs. In addition, round steel is produced and supplied in a coil shape, which is easy and inexpensive. In addition to the low worry of loss, the steel types are also relatively abundant, which has great advantages.

[Example of using friction welding method for end thread] As in the eighth embodiment shown in Fig. 15A, the frictional welding method may be used for the end thread. The friction welding method is to make the jointed screw rods (external thread parts) contact each other by friction welding at the end of the steel bar, and join with the connector 2 to form an integrated mechanical steel bar joint. As shown in Figure 15A, the special-shaped steel bar 1 on one side (the left part of Figure 15A) is the same as that shown in Figures 3A to 3D, and the screw groove of the incomplete threaded part 1ca at the base end of the external threaded part 1c will be connected. The screw top 2aa of the internal thread portion 2a of the tool 2 is screwed at least to a depth until it is bitten into an elastically deformed state. Thereby, an anti-loosening torque is generated between the external thread part 1c and the coupling 2. As shown in FIG. Moreover, the steel bar 1 may also be round steel. In addition, in the example of FIG. 15A, the anti-loosening nut 15 is used in order to ensure rigidity, but it does not need to be the anti-loosening nut 15.

As shown in the modified example of FIG. 15B, the base end of the external thread portion 1c of the deformed steel bar 1 may not have the incomplete thread portion 1ca. At this time, the burr portion 160 formed at the time of friction welding has a function of realizing a brake. That is, by locking the connector 2 into the external thread portion 1c, the end of the connector 2 can be strongly abutted against the burr portion 160 . Thereby, an anti-loosening torque is generated between the external thread part 1c and the coupling 2. As shown in FIG.

Fig. 17 shows a suggested example of a steel bar joint used in combination with a joint utilizing an incomplete thread portion of an external thread portion according to the present invention. It is also possible to use a steel bar joint related to one of the embodiments for the steel bar joint at any one of the plurality of steel bars connected into one line, and use the steel bar joint of the reference proposal example shown in FIG. 17 for the remaining places. In Fig. 17, the front ends of both reinforcing bars 1 and 1 are brought into contact with each other, and the incomplete thread avoiding nut 15A of the external thread portion 1c of one reinforcing bar 1 is screwed together. At this time, abutting against the incomplete thread portion avoiding nut 15A can prevent the connector 2 from being screwed to the incomplete thread portion. In this way, the entire connector 2 is screwed to the complete threaded portion, improving rigidity. In addition, the incomplete thread portion avoiding nut 15A is not limited to being made of steel, for example, may be made of resin.

Also, in any of the 2nd to 5th embodiments shown in Fig. 7 to Fig. 10, round steel can be used in the same way instead of deformed steel bars.

＜Structure for Rebar Assembly＞ Fig. 18 is a front view showing a state in which a steel bar assembly according to a ninth embodiment of the present invention is attached to a formwork. Fig. 18 shows a reinforcement assembly A1 constituting one of the beams or columns on the right, and a reinforcement assembly A2 constituting the other of the beams or columns on the left. This example shows the case where the steel bar assemblies A1 and A2 are used as beams. In addition, the reinforcement assemblies A1 and A2 on the left and right are identical assemblies using the same number of main reinforcements (reinforcement bars) 101 and the same or different numbers of ribs 102 .

In Fig. 18, the steel bar assemblies A1 and A2 are arranged separately in the vertical direction in Fig. 18 and in the surface direction of the paper, and parallel to each other in the left and right directions (in this example, the horizontal direction) )extend. A plurality of ribs 102 serving as shear reinforcing bars are wound around these reinforcing bars 101 . The reinforcing bar 101 of this embodiment is a special-shaped reinforcing bar formed with protrusions including ribs extending in the longitudinal direction on the periphery and knots extending in the peripheral direction at regular intervals, but it may be a normal round bar.

The external thread part 115 is formed in the end part of the reinforcement bar 101 by rolling, for example. The external thread portion 115 can also be formed separately from the steel bar 101 so as to be welded to the end surface of the steel bar 101 . In the boundary portion between the external thread portion 115 and the reinforcing bar main body, an incomplete thread portion 115a is formed similarly to the above-mentioned embodiment. The outer threaded portion 115 is screwed with the cylindrical body 110 having an internal threaded portion formed on the inner surface thereof.

Similar to the above-mentioned embodiment, the screw groove of the incomplete thread portion 115a at the base end of the external thread portion 115 of the steel bar 101 is screwed so that the screw top of the internal thread portion 114 of the cylindrical body 110 bites into at least an elastically deformed state. depth. Thereby, an anti-loosening torque is generated between the external thread part 115 and the cylindrical body 110 . In this cylindrical body 110 , as will be described later, the mounting threaded body 106 inserted from the outside of the formwork 107 is locked, whereby the reinforcing bar assembly A1 is attached to the formwork 107 . The reinforcement assembly A2 on the left also has the same structure.

Each steel bar assembly A1, A2 is the state that the formwork 107 is installed in the factory, and the raw concrete is drilled in the formwork 107 to make a reinforced concrete body P such as a beam or a column (hereinafter, simply referred to as "PC concrete"). Condensate P"). but Yes, the reinforcement assemblies A1 and A2 with the formwork 107 can also be transported to the construction site, and the raw concrete can be placed on the formwork 107 at the construction site, or the reinforcement 101, the rib bar 102, the tubular body 110. The formwork 107 is transported to the construction site respectively, and the steel bar assemblies A1 and A2 with the formwork 107 are made on the construction site, and raw concrete is laid in the formwork 107 .

Next, the threaded body 106 is pulled out to remove the mold frame 107, and the steel bars 101, 101 of the left and right PC concrete bodies P are connected by the steel bar joint B1. In this example, although the PC concrete body P is set as a beam, when the PC concrete body P is a column, the reinforcing bars 101 and 101 connecting the upper and lower pair of PC concrete bodies P are connected.

In addition, as shown by the dotted line of two dots in FIG. 18, a concrete protrusion 170 may be provided at the center of the end surface (lower end surface) of the PC concrete body P. As shown in FIG. At this time, the lower end surface 172 of the concrete body 170 connected to the end surface (upper end surface) 180 of the PC concrete body P is loaded while the PC concrete body P after the formwork 107 has been removed is suspended by a crane. In this state, for example, the reinforcement joints B1 at the four corners of the rectangular columnar PC concrete body P are installed. The load is borne by the concrete protrusion 170, so the steps after installing the steel bar joint B1 at the four corners do not require a crane, and the crane can be moved to other operations. Next, install the other rebar connector B1. Thereby, work efficiency is improved.

<Construction for Rebar Joints>

Use Figure 19 to illustrate the reinforcement joint B1. As shown in the exploded perspective view of FIG. 19, this steel bar joint B1 includes: a cylindrical body 110 serving as a connector with an internal thread portion 114 formed on the above-mentioned inner surface; a joint member 111 having a joint external thread portion 113 at one end; And the connection member 119 which connects a pair of opposing joint members 111 and 111 mutually.

The connecting member 119 is a pair of upper and lower clamping joint members 111 in a sandwich structure, and can be displaced in the long direction (axial direction) X and its orthogonal direction Y. The longitudinal direction X of the joint member 111 and the reinforcing bar 101 is common. Let Y be the direction perpendicular to the longitudinal direction X and parallel to the main surface of the main body 112 of the joint member 111 , that is, perpendicular to the through hole 117 (described later). Also, let Z be a direction perpendicular to both directions X and Y. The cylindrical body 110 is embedded in the concrete body P as described above.

Here, the outer shape of the cylindrical body 110 is hexagonal in cross section, and the internal thread portion 114 screwed to the external thread portion 115 of the bar exposed at the end of the bar 101 is formed on the inner surface thereof. The cylindrical body 110 may also be circular or polygonal in cross section. The rebar external thread portion 115 is an axially inner portion screwed to only a portion of the internal thread portion 114 of the cylindrical body 110 . As shown in FIG. 20 , the joint member 111 is provided with a flat main body portion 112 and a joint male thread portion 113 at the tip thereof. The joint external thread portion 113 is screwed to the internal thread portion 114 of the cylindrical body 110 .

Three through holes 117 are formed at predetermined intervals (for example, 60 mm) in the main body portion 112 . Although the number of through-holes 117 is three in this example, it may be one, two, or four or more. Also, this through-hole 117 is a free-fitting hole (excessively large hole) having an outer diameter of several millimeters larger than that of a high-strength bolt or an ultra-high-strength bolt (hereinafter, referred to simply as a "bolt") 125 described later. ). Friction adjusting portions 117 a formed of annular protrusions or chamfers are formed on edge portions at both ends of the through hole 117 . Thereby, when the bolt 125 is fastened with a large force, the protrusion is crushed, or a part of the connecting member 119 enters the chamfered depression, which can increase the frictional force and improve the force transmission efficiency.

The cylindrical body 110 and the joint member 111 of Fig. 19 are disposed so that the same structure faces the longitudinal direction (at this time, the reinforcing bar for setting the beam is therefore in the horizontal direction), and is screwed to the joint external thread portion 113 of each joint member 111. Corresponding to the internal thread portion 114 of the cylindrical body 110 . When connecting the PC concrete bodies P and P causes an obstacle, the joint member 111 may be attached to the cylindrical body 110 of the PC concrete body P afterward. A slight gap S (about 70 mm) exists between the joint members 111 and 111 . The swivel joint member 111 increases or decreases the locking amount of the cylindrical body 110 to change the size of the gap S to absorb the error in the separation dimension between the reinforcement bars 101 and 101 .

Specifically, the gap S is provided so that the joint member 111 can be rotatably removed when the joint member 111 collides during construction. In addition, when connecting the reinforcing bars 101, 101 whose axial centers deviate from each other by bolts or the like, a gap S is provided to facilitate bending of the connecting members 119, 119.

Fig. 21 is an enlarged view showing a structure in which a reinforcing bar 101 is attached to the formwork 107 of Fig. 18 . As shown in FIG. 21, screw holes 120 are formed in advance on the outer end surface of the externally threaded body 116 for the mold frame. The external threaded body 116 for the mold frame is mounted on the mold frame 107 by means of the mounting threaded body 106, and the cylindrical body 110 is screwed together with the external threaded body 116 for the mold frame. Furthermore, a rebar male thread part 115 of a steel bar is screwed to the female thread part 114 on the inner surface of the cylindrical body 110 . At this time, as described above, the threaded groove of the incomplete threaded portion 115a is screwed so that the crest of the internally threaded portion 114 of the cylindrical body 110 bites at least to the depth of the elastically deformed state. In this state, as mentioned above, the raw concrete is driven to the setting surface 135 in the formwork 107, and the PC concrete body P is obtained by removing the formwork 107.

When the reinforcing bars 101 and 101 are connected, the formwork external thread body 116 is removed with a tool, and the internal thread portion 114 on the inner surface of the cylindrical body 110 is exposed from the end surface of the PC concrete body P to the outside. The female thread portion 114 exposed here is screwed to the joint male thread portion 113 of the joint member 111 shown in FIG. 19 . And, on the outside of the mold frame 107, as shown in Fig. 21, the iron frame 109 for the positioning of the reinforcement can be freely assembled and disassembled by inserting the installation threaded body 106.

As a modified example of installing the steel bar 101 on the formwork 107, the threaded body 116 for the formwork can also be omitted, as shown in Fig. 21, the two-dot dashed line shows the lengthened installation threaded body 116, which is screwed into the screw hole 120A provided on the end surface of the steel bar 101 , thereby installing the steel bar 101 with the cylindrical body 110 on the formwork 107 . In this modified example, the formwork 107 is removed so that the internal thread portion 114 of the cylindrical body 110 is exposed from the end surface of the PC concrete body P to the outside.

The main body portions 112, 112 of these joint members 111, 111 are held in a sandwich structure by abutting against a pair of connection members 119, 119 from the front and back surfaces as shown in Fig. 22 . The connection member 119 is formed of a flat plate, and six connection holes 127 are provided at positions corresponding to the through holes 117 of the joint member 111 . A bolt 125 , which is an example of a fastening member, is inserted through the connecting hole 127 of one connecting member 119 , and the through hole 117 inserted through the joint member 111 protrudes from the connecting hole 127 of the connecting member 119 on the opposite side, and fastened with a nut 130 . The front end of the member (bolt) 125 . Therefore, the fastening member is composed of the bolt 125 and the nut 130 . In addition, as shown by the dotted line in FIG. 22, the tightening length checking hole 150 may be provided in the cylindrical body 110 similarly to the first embodiment (the tightening length checking hole 2b in FIG. 1B).

The connecting hole 127 is not an oversized hole but a normal hole. As mentioned above, between the oversized hole 117 and the bolt 125, there is a larger gap than that of the usual screw connection, and only the amount of the gap is connected by the connecting member 119 so that the joint members 111, 111 can be connected in the longitudinal direction. X and its orthogonal direction Y displacement. In this way, as shown in Fig. 23, the adjacent PC concrete bodies P, P are connected by the steel joint B1.

＜Connection work for joints with steel bars＞ When connecting the two steel bars 101, 101 as the reinforcement of the beam or column with the steel bar joint B1, first lock the joint external thread portion 113 of the joint member 111 into the internal thread portion 114 of the cylindrical body 110 in FIG. 19 . At this time, if necessary, lock nuts 131 shown in FIG. 22 are attached to both ends of the cylindrical body 110 . Thereby, the joint male thread portion 113 is screwed to the axially outer portion of the other portion in a state where the reinforcing bar male thread portion 115 is fastened to the axially inner portion of the internal thread portion 114 of the cylindrical body 110 .

In this state, as described above, the joint members 111, 111 are sandwiched by the plate-shaped connecting members 119, 119 to hold the joint members 111, 111 in a sandwich structure, and the six bolts 125 are inserted through the connecting holes 127 of the connecting member 119 and the joint members. 111 through holes 117 . At the front end of the bolt 125, a nut 130 is screwed and fastened through a washer 134 as necessary. The gaps between the PC concrete bodies P and P connected in this way are buried after concrete is drilled on site. Therefore, the reinforcing bar joint B1 is buried in concrete and is not exposed to the outside.

＜Aiming at action and effect＞ The steel bar joint B1 according to the present invention constituted as above does not use an expensive slurry material such as mortar and takes several days to harden, but only needs to be screwed together. Therefore, reduction of construction cost and shortening of construction period can be achieved. Also, the pair of joint members 111 facing each other in Fig. 19 has a main body portion 112 and a joint external thread portion 113, and the main body portions 112, 112 of the pair of joint members 111, 111 face each other in the longitudinal direction. 125 and 130 connect the connection member 119 and the joint member 111 in a detachable manner. Therefore, the connection structure becomes simple. As a result, not only reinforcement assembly in a factory but also reinforcement assembly at a construction site can be performed quickly and easily.

Although the joint members 111 and 111 are concentric in Fig. 23, as shown in Fig. 24, they may be between the axis X1 in the longitudinal direction of one joint member 111 and the axis X2 of the other joint member 111. There is an eccentricity C1, or an axial displacement, that is, there may be a change in the size of the gap S. At this time, it is also because the through hole 117 of the joint member 111 and the connecting hole 127 of the connecting member 119 are too large holes. Smooth connection is possible by absorbing the deviation of the reinforcing bars 101, 101 only by the amount.

In order to perform the fastening work of the bolt 125 smoothly, the direction of the main body portion 112 of the joint member 111 may be oriented in a direction in which fastening workability is good. At this time, eccentricity occurs in the Z direction shown in FIG. 22 , and a gap occurs between the main body portion 112 and the connection member 119 . A joint plate can also be inserted in this gap, but the joint plate may not be required. Since there is a gap S in the longitudinal direction X between the joint members 111 and 111, the joint member 111 and the connection member 119 are deformed by tightening the bolt 125 strongly. And tilting can eliminate the Z-direction gap between the two.

Moreover, the main body part 112 of the joint member 111 is provided between a pair of connection members 119 and 119 shown in FIG. 22 . Therefore, the main body portion 112 of the joint member 111 is firmly held in a sandwich structure by the pair of connecting members 119, 119, so that the reliability of joining the pair of reinforcing bars 101, 101 to each other can also be improved.

In addition, in the steel bar assemblies A1 and A2 related to the present invention, a plurality of steel bars 101 are reinforced in parallel and combined with ribs 102, and the external threaded part 115 of the steel bar formed on the steel bar 101 is screwed with an inner surface. The cylindrical body 110 of the threaded portion 114 . The rebar external thread portion 115 penetrates the axially inner portion of the internal thread portion 114 to expose the axially outer portion of the internal thread portion 114 to the outside of the reinforcing bar assembly A1, A2. Therefore, the female thread portion 114 is exposed here and screwed to the joint external thread portion 113 of the joint member 111 , whereby the joint member 111 can be easily connected to the steel bar 101 . As a result, the efficiency of the work of connecting the reinforcing bars 101 and 101 of the reinforcing bar joint B1 can be achieved. Thereby, even when mass-producing reinforced concrete structures such as beams or columns in a factory, or when concrete is drilled at a construction site, work efficiency can be improved.

Next, the steel bar joint according to the tenth embodiment will be described with reference to Fig. 25 . This tenth embodiment is basically the same as that of the ninth embodiment shown in FIG. 22, except that the cylindrical body 110 of the reinforcement joint B1 is not embedded in the PC concrete body P. The externally threaded portion 115 at the end of the steel bar 101 protrudes from the PC concrete body P, and the cylindrical body 110 is screwed to the protruding externally threaded portion 115 at the construction site. The connection of the joint member 111 to the cylindrical body 110 and the connection of the joint member 111 and the connection member 119 are the same as those of the ninth embodiment.

Next, the steel bar joint according to the eleventh embodiment will be described with reference to Fig. 26 . The eleventh embodiment is basically the same as the ninth embodiment shown in FIGS. 19 to 24, and the frictional welding method is used as the end thread of the eighth embodiment of the steel bar 101 in FIG. 15 . That is, in the screw groove of the incomplete thread portion 115a of the steel bar 101, the screw top of the cylindrical body 110 is bitten at least to an elastically deformed state. Other configurations are the same as those of the ninth embodiment. In addition, as shown by the two-dot dashed line in FIG. 26 , a lock nut 140 may be screwed to the joint external thread portion 113 of the joint member 111 to secure rigidity.

Next, the steel bar joint according to the twelfth embodiment will be described with reference to Fig. 27 . In the twelfth embodiment, one of the opposing pair of joint members 111 (the left side in FIG. 27 ) has the same configuration as that of the ninth embodiment shown in FIGS. 19 to 24, and the other (the right side in FIG. 27 ) The shape is different from that of the ninth embodiment. Specifically, a short steel bar 145 made of round steel is joined to the main body portion 112 of the other (right side in FIG. 27 ) joint member 111 by, for example, welding. The steel bar 145 of the joint member 111 is joined to the steel bar 101 by frictional compression. Other configurations are the same as those of the ninth embodiment.

Next, with reference to Fig. 28, a reference suggestion example of a steel bar joint that does not use an incomplete thread portion of the present invention will be described. The reference suggestion example is basically the same as the configuration of the ninth embodiment shown in FIG. 19 , and differs only in that the reinforcing bar 101 and the cylindrical body 110 are fixed by the locking nut 140 . That is, the external thread portion of the steel bar 101 is screwed to the internal thread portion 114 on the inner surface of the cylindrical body 110 . 115, fixed with anti-loosening nut 140. Other configurations are the same as those of the ninth embodiment.

As described above, although suitable embodiments are described while referring to the drawings, various additions, changes, or deletions are possible without departing from the gist of the present invention. Therefore, the above description is also included in the scope of the present invention.

The implementation forms in Fig. 18 to Fig. 27 and the reference suggestion example in Fig. 28 include the following aspects 1 to 5.

[Form 1]

The steel bar joint related to Aspect 1 is a steel bar joint that connects the ends of a pair of steel bars facing each other in the longitudinal direction, and includes: a cylindrical body with a female thread portion formed on the inner surface; threaded portion; and a connecting member, which is connected so that a pair of opposing joint members can be displaced in the longitudinal direction and the direction perpendicular to each other, and the external thread of the steel bar formed at the end of one of the above-mentioned steel bars is screwed to one end of the above-mentioned cylindrical body part, and the other end part is screwed to the above-mentioned joint external thread part of one end part of the above-mentioned joint member.

[Form 2]

The steel bar joint related to Aspect 2 is the steel bar joint described in Aspect 1, wherein the joint member has a main body portion and the joint external thread portion, and the main bodies of the pair of joint members face each other in the longitudinal direction. The above-mentioned connection member and the above-mentioned joint member are detachably connected by a fastening member.

[Form 3]

The steel bar joint according to Aspect 3 is the steel bar joint described in Aspect 2, wherein the main body portion of the joint member is provided between a pair of the connection members.

[Aspect 4]

The steel bar assembly related to aspect 4 is a steel bar assembly in which a plurality of steel bars are reinforced in parallel and combined with ribs, and the external thread part formed at the end of the steel bar has a female thread on the screwed inner surface The cylindrical body of the above-mentioned steel bar external thread part penetrates the axially inner part of the above-mentioned internal thread part, and makes the axially outer part of the above-mentioned internal thread part exposed to the outside.

[Aspect 5]

The reinforced concrete body related to Aspect 5 is equipped with the steel bar joint described in any one of Aspects 1 to 3, and the above-mentioned cylindrical body and the above-mentioned steel bar of the above-mentioned steel bar joint are embedded in concrete so that the outer end surface of the above-mentioned cylindrical body The internal thread part is exposed from the end surface of the above-mentioned concrete.

1. 101: steel bar (special-shaped steel bar or round steel)

1b: protruding strip

1ba: section

1bb: rib

1c, 115: external thread part

1ca, 115a: Incomplete threaded part

2: Connector

2a: Internal thread part

2aa: screw top

2b: Fastening length confirmation hole

15: Lock nut

102: ribs

106: bolt (fastening component)

107: mold frame

110: cylindrical body (connector)

111: joint member

112: Main body

113: Connector external thread part

114: internal thread part

115: Reinforcement external thread part

117: through hole

117a: Friction adjustment part

119: Connecting components

120: screw hole

127: Connection hole 130: Nut (fastening member) A1, A2: steel bar assembly B: Steel joint P: PC concrete body such as beam or column

The present invention can be understood more clearly from the description of the following suitable embodiments with reference to the drawings. However, the present embodiment and drawings are merely for illustration and description purposes, and are not used to limit the scope of the present invention. The scope of the present invention is determined by the appended claims. In the appended drawings, the same component number in the plural drawings means the same or corresponding parts. Fig. 1A is a cross-sectional view of a joint utilizing the incomplete thread portion of the external thread portion according to the first embodiment of the present invention. Fig. 1B is an enlarged front view of the vicinity of the connector of the joint utilizing the incomplete thread portion of the same external thread portion. Fig. 2A is an explanatory diagram of the manufacturing process of the external thread portion of the same joint. Fig. 2B is an explanatory diagram of the manufacturing process of the external thread portion of the same joint. Fig. 2C is an explanatory diagram of the manufacturing process of the external thread portion of the same joint. Fig. 3A is a partially enlarged cross-sectional view showing enlarged engagement portions of threaded portions of the same joint. Fig. 3B is an enlarged view of part IIIB in Fig. 3A. Fig. 3C is an enlarged view of part IIIC in Fig. 3A. Fig. 3D is an enlarged view of part IIID in Fig. 3A. Fig. 4A is a diagram illustrating a specific example of fastening work of the same joint. Fig. 4B is a diagram illustrating a specific example of fastening work of the same joint. FIG. 4C is a diagram illustrating a specific example of fastening work of the same joint. FIG. 4D is a diagram illustrating a specific example of fastening work of the same joint. Fig. 5 is an explanatory view showing the rolling process of the externally threaded portion of the steel bar after being processed into a perfect circle. Fig. 6A is a cross-sectional view of an example in which an anchor plate is screwed together using the same steel bar. Fig. 6B is a cross-sectional view of an example in which the anchor plate is screwed together using the same steel bar. Fig. 7 is a cross-sectional view of a joint utilizing an incomplete thread portion of a male thread portion according to a second embodiment of the present invention. Fig. 8 is a cross-sectional view of a joint utilizing an incomplete thread portion of a male thread portion according to a third embodiment of the present invention. Fig. 9 is a cross-sectional view of a joint utilizing an incomplete thread portion of a male thread portion according to a fourth embodiment of the present invention. Fig. 10 is a cross-sectional view of a joint utilizing an incomplete thread portion of a male thread portion according to a fifth embodiment of the present invention. Fig. 11 is a diagram schematically showing an example of a reinforcing bar of the overall system of the joint utilizing the incomplete thread portion of the external thread portion. Fig. 12 is a longitudinal sectional view of the sixth embodiment of the present invention, which uses round steel instead of the special-shaped steel bar in Fig. 1. Fig. 13 is a partially enlarged cross-sectional view showing the left part of No. 12 in an enlarged manner. Fig. 14 is a longitudinal sectional view of a joint in which one of the left and right round steels is a reverse screw thread according to the seventh embodiment of the present invention. Fig. 15A is a cross-sectional view of a joint utilizing an incomplete thread portion of a male thread portion according to an eighth embodiment of the present invention. Fig. 15B is a cross-sectional view of a modified example of a joint utilizing an incomplete thread portion of the same external thread portion. Figure 16 is a longitudinal sectional view of a conventional steel bar joint. Fig. 17 is a longitudinal sectional view of the steel bar joint of the reference proposal. Fig. 18 is a front view of a steel bar joint and a steel bar assembly according to a ninth embodiment of the present invention. Fig. 19 is an exploded perspective view of a rebar joint screwed to a rebar external thread portion at the end of the rebar according to the embodiment. Figure 20 is an enlarged perspective view of a joint member of the same steel bar joint. Fig. 21 is an enlarged cross-sectional view showing another mounting structure of the end surface of the externally threaded portion of the steel bar and the formwork. Figure 22 is a side view of a steel bar joint. Figure 23 is a front view of the same rebar joint. Fig. 24 is a front view showing a joint of steel bars in a state where connecting members are removed in the case of connecting eccentric steel bars. Fig. 25 is a side view of a steel bar joint according to the tenth embodiment. Fig. 26 is an enlarged perspective view of a joint member of a steel bar joint according to an eleventh embodiment of the present invention. Fig. 27 is a front view of a steel bar joint related to the twelfth embodiment of the present invention. Fig. 28 is an exploded perspective view of a steel bar joint screwed to the end of the steel bar of the steel bar joint of the reference proposal example.

1: Steel bar (special-shaped steel bar or round steel)

1a: Rebar body

1b: protruding strip

1ba: section

1bb: protruding strip

1c: external thread part

1ca: Incomplete threaded part

2: Connector

2a: Internal thread part

2b: Fastening length confirmation hole

L0: exposed length

L1: thread length

L2: thread length

Claims (9)

A joint that utilizes the incomplete threaded part of the external threaded part, and connects a pair of steel bars with a cylindrical connector that is screwed to the external threaded part provided at the ends of the two steel bars. The external threaded part of the above-mentioned There is no intervening joint between the outer peripheral surface and the inner peripheral surface of the above-mentioned connector, and one or both of the above-mentioned pair of steel bars bite into the top of the internal thread part of the above-mentioned connector to at least The elastically deformed state is deeply screwed to the screw groove of the incomplete threaded portion at the base end of the externally threaded portion of the steel bar, thereby generating an anti-loosening torque between the externally threaded portion and the connector, and the externally threaded portion In the full thread portion, an axial gap is generated between the crest of the internal thread portion and the crest of the external thread portion. The joint utilizing the incomplete thread portion of the external thread portion as described in claim 1, wherein two steel bars are provided to make the front ends of the opposite external thread portions in the connector contact each other. The joint using the incomplete thread portion of the external thread portion according to claim 1 or 2, wherein, for any one of the pair of steel bars, the screw top of the connector is at least elastically deformed and bit into the above-mentioned The screw groove of the incomplete thread part is used to screw the anti-loosening nut to the external thread part of any other steel bar. The joint utilizing the incomplete thread portion of the external thread portion as described in claim 1 or 2, wherein a tightening mechanism is formed on the connector to confirm that the pair of steel bars are locked into the connector up to a predetermined minimum length of fastening. Fixed length confirmation hole. As described in Claim 1 or 2, the use of the external thread part is different A joint of a complete thread portion, wherein one or both of the above-mentioned pair of steel bars has a plurality of nodes at intervals in the longitudinal direction on the periphery of a circular shaft-shaped steel bar body, and has protrusions extending in the longitudinal direction. Strips of special-shaped steel bars. The joint utilizing the incomplete thread portion of the external thread portion according to Claim 1 or 2, wherein one or both of the above-mentioned pair of steel bars are round steel bars. A steel bar joint is a steel bar joint that utilizes the incomplete threaded part of the external threaded part of the steel bar, and connects the ends of a pair of steel bars opposite in the longitudinal direction to each other. It has: a cylindrical body with internal threads formed on the inner surface part; a joint member, which has a joint external thread part at one end; and a connecting member, which displaceably connects a pair of joint members relative to each other in the long direction and the direction perpendicular to it, and is formed by screwing on one end of the above-mentioned cylindrical body. The external threaded part of the steel bar at the end of one of the above-mentioned steel bars is screwed to the external threaded part of the joint at one end of the joint member at the other end, so that the screw top of the internal threaded part at one end of the cylindrical body is at least The screw groove of the incomplete thread part at the base end of the external thread part of the steel bar is screwed deeply to the elastic deformation state, thereby generating an anti-loosening torque between the external thread part of the steel bar and the cylindrical body, and the joint member It has a main body part and the above-mentioned joint external thread part, so that the main bodies of the above-mentioned pair of joint members face each other in the longitudinal direction, and the above-mentioned connecting member and the above-mentioned connecting member are detachably connected by fastening members. header widget. The steel bar joint according to claim 7, wherein the main body portion of the joint member is provided between a pair of the connection members. A reinforced concrete body comprising the steel bar joint described in claim 7 or 8, the above-mentioned cylindrical body and the above-mentioned steel bar of the above-mentioned steel bar joint are embedded in concrete, so that the internal thread portion of the outer end surface of the above-mentioned cylindrical body is separated from the above-mentioned concrete end exposed.

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