JPH1171859A - Threaded reinforcement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide threaded reinforcement on which markings for checking the threaded engagement depth of the threaded reinforcement are formed in such a way that they will not disappear even in a severe environment. SOLUTION: Marking grooves 14, 16, 18 (recesses) are cut in the unthreaded part 12 of threaded reinforcement 10 and in positions away from an end face 10a. The clearance between the marking 14 and the end face 10a indicates the required threading length. Therefore, when both ends of a joint 20 are located between the markings 14, 16, it can be made sure that the threaded reinforcement 10 has been threaded into the joint 20 by the required threading length or more. when a lock nut 30 is used, it can be made sure that the threaded reinforcement 10 has been threaded into the joint 20 by the required threading length or more, by ensuring that the end face 30a of the lock nut 30 is located between the marking grooves 16, 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw rebar which is connected by screwing to a joint.

[0002]

2. Description of the Related Art As shown in FIG. 6, in a connecting device for a screw rebar, ends of a pair of screw rebars 1 to be connected are screwed to a cylindrical joint 2, and if necessary, the joint 2 is injected. The grout material (not shown) is injected from the hole 3 to connect the screw rebar 1. By the way, in order to obtain a sufficient connection strength between the screw rebars 1, each screw rebar 1
It is necessary to make the screwing depth of the joint 2 into the required amount or more. For this reason, conventionally, a marking 5 extending in the axial direction with paint is provided at a position apart from the distal end surface 1a of the screw reinforcing bar 1. Distance D ₁ of the between one end (the end closer to the front end surface 1a of the screw rebar 1) and the front end surface 1a of the screw reinforcing bar 1 of the marking 5 is equivalent to the necessary screwing depth. Distance D ₂ between the other end and the threaded rebar 1 tip 1a of the marking 5 is equivalent to engagement depths prohibit any further screwing. This distance D ₂
Is for securing the required screwing depth of the threaded reinforcing bar 1 of the other party. Therefore, if the grout material is injected in a state in which both ends of the joint 2 are at positions corresponding to the markings 5 of the double-threaded reinforcing bars 1, that is, in a state where a sufficient screwing depth is secured, a sufficient connection strength can be secured. In addition, when the connection state is inspected at a later date, the marking 5 and the joint 2
The screwing depth of the screw reinforcing bar can be confirmed from the positional relationship with both ends of the screw reinforcing bar.

[0003]

As described above, conventionally, in order to confirm the screwing depth of the threaded rebar 1, the threaded rebar 1
Although the marking 5 is applied to the surface, there is a possibility that the marking 5 is peeled off when left in a severe environment because the marking 5 is a paint. In addition, in order to form the markings 5, the operation of accurately applying or spraying a paint on a predetermined location with a predetermined length was inefficient.

[0004]

According to a first aspect of the present invention, in a threaded rebar connected by screwing an end to a joint, at least one of a pair of non-threaded portions extending in an axial direction is attached to at least one of a pair of non-threaded portions from an end face. It is characterized in that a concave portion for marking is formed which represents a position separated by the required screw length.

According to a second aspect of the present invention, the threaded reinforcing bar according to the first aspect is formed as a first marking recess at a position apart from the tip end surface by a required screw length. Furthermore, a second marking recess is formed in the non-threaded portion at a position away from the first marking recess by a predetermined distance in a direction opposite to the tip end surface. According to a third aspect of the present invention, in the threaded reinforcing bar according to the second aspect, the non-threaded portion further includes a second thread at a position away from the second marking recess by the predetermined distance in a direction opposite to the tip end face. (3) A concave portion for marking is formed. The invention of claim 4 is
3. The threaded reinforcing bar according to claim 2, wherein the non-threaded portion is further away from the first marking recess by a thickness of a lock nut disposed at both ends of the joint in a direction opposite to the tip end surface. A third marking concave portion is formed at the deviated position, and a fourth marking concave portion is formed at a position away from the third marking concave portion by the predetermined distance. According to a fifth aspect of the present invention, in the threaded reinforcing bar according to any one of the first to fourth aspects, the concave portion for marking comprises a marking groove extending in a direction perpendicular to the axial direction.

According to a sixth aspect of the present invention, in the threaded rebar according to the first aspect, the marking recess comprises a marking groove extending over a predetermined length in the axial direction, and the marking groove is provided on a side closer to the tip end surface. It is characterized in that one end represents a position separated by the required screwing depth. According to a seventh aspect of the present invention, in the threaded rebar according to the sixth aspect, the marking groove is provided as a first marking groove, and the non-threaded portion has a second marking recess.
A second marking groove extending in the axial direction over the predetermined length is formed, and the first and second marking grooves are arranged to be shifted from each other in a circumferential direction, and one end of the second marking groove closer to the distal end surface is It is characterized in that the first marking groove is separated from the one end of the first marking groove in a direction opposite to the tip end surface by a thickness of a lock nut disposed at both ends of the joint. According to an eighth aspect of the present invention, in the threaded reinforcing bar according to the sixth or seventh aspect, an auxiliary groove extending in parallel with the marking groove is provided on an end surface of a thread continuous with the non-threaded portion in a range of the length of the marking groove. It is characterized by being formed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a threaded reinforcing bar according to a first embodiment of the present invention will be described with reference to FIG. Screw rebar 10
Is a pair of thread forming portions 11 facing each other in the radial direction, and a pair of non-threading portions 1 arranged between the pair of thread forming portions 11.
And 2. The pair of non-threaded portions 12 also face each other in the radial direction. Each thread forming part 11 and the non-thread part 12 extend on a straight line.

[0008] The thread forming portion 11 has threads 13 formed at a predetermined pitch. The screw threads 13 formed on the pair of screw forming portions 11 are arranged on a continuous spiral line, whereby the screw reinforcing bar 10 has a screw function. Both end faces of the thread 13 are connected to the non-threaded portion 12. In the present embodiment, the end face of the thread 13 and the non-threaded portion 12 form a substantially flat continuous surface.

The one non-threaded portion 12 is formed with three marking grooves 14, 16, and 18 (first, second, and third marking recesses) having a substantially semicircular cross section. These marking grooves 14, 16, 18 extend linearly in a direction perpendicular to the axis of the screw rebar 10, and extend to the end face of the thread 13 when the thread 13 is formed at the formation position. . In other words, the marking grooves 14, 16, 1
8 is formed over the entire width of the substantially flat surface formed by the end faces of the non-threaded portion 12 and the thread 13. The marking grooves 14, 16, and 18 are provided on the tip surface 10 of the screw reinforcing bar 10.
are formed in order in a direction away from a, and are separated by a distance Dx equal to each other. Marking grooves 14, 16, 1
8 and the tip surface 10a are distances Da, Db,
Dc apart. These distances Dx, Da, Db, D
The meaning of c will be described later.

Next, the marking grooves 14, 16, 18
A method for forming the will be described. The screw rebar 10 manufactured in the hot rolling step is cut into a predetermined length,
As shown in (B), the end is positioned by the positioning device 50. More specifically, the positioning device 50
Has a flat first receiving portion 51 and a second receiving portion 52, and the tip surface 10 a of the screw reinforcing bar 10 is applied to the first receiving portion 51, and the marking grooves 14, 16, and 18 are not formed. By applying the non-screw part 12 to the second receiving part 52, the end of the screw reinforcing bar 10 is positioned. In this positioning state, the marking member 60 is pressed against the non-screw part 12 on the side opposite to the second receiving part 52. More specifically, the marking member 60 is formed with projections 61, 62, and 63 having a semicircular cross section and an equal length extending in a direction perpendicular to the paper surface of FIG. Is pressed into a flat surface formed by the non-threaded portion 12 and the end face of the thread 13, whereby the marking grooves 14, 16, 18 corresponding to the projections 61, 62, 63 are formed.

As described above, the marking grooves 14, 16, 18 can be marked at accurate positions by a relatively simple method. Moreover, the marking and engraving work can be performed on the production line of the screw reinforcing bar 10 while the screw reinforcing bar 10 is hot. The productivity can be increased as compared with the case of forming. The marking grooves 14, 16, 18 do not disappear even if left in a severe environment.

Next, an example of a method of connecting the screw reinforcing bar 10 having the above configuration will be described with reference to FIG. In this connection, only the joint 20 is used. Fitting 2
Numeral 0 has a hexagonal or circular cylindrical cross section, and a female screw 21 for screwing the screw rebar 10 is formed on the inner periphery. An injection hole 22 is formed at the center of the joint 20 in the longitudinal direction for injecting a grout material.

The ends of the two threaded rebars 10 are screwed from both ends of the joint 20. In this screwed state, one screw reinforcing bar 1
0 is screwed into the other threaded reinforcing bar 10 and the joint 20, and a predetermined torque is applied so that the tip surfaces 10a come into contact with each other. As a result, the ends of the two screw rebars 10 are screwed to the joint 20 without play.

In the above screwing operation, it is necessary to confirm that the left and right screw rebars 1 are screwed to a required screwing depth or more, respectively.
One marking groove 14, 16 is used. To elaborate,
The distance Da (see FIG. 1A) between the marking groove 14 and the tip end surface 10a corresponds to the minimum required screwing depth of the screw reinforcing bar 10. The distance Db (see FIG. 1B) between the marking groove 16 and the tip end surface 10a corresponds to a screwing depth that prohibits further screwing. This distance Db is for securing the required screwing depth of the threaded reinforcing bar 1 of the other party.
The distance Dx between the marking grooves 14 and 16 is
(Db-Da). Therefore, the joint 20
The both ends of the marking groove 1 of each screw reinforcement 10
If it is located between 4 and 16, the two threaded rebars 10 are also screwed to the joint 10 with the required screw length or more.

After confirming that the two threaded rebars 10 are screwed into the joint 20 with the required screw length or more as described above, the injector ( (Not shown) nozzle and grout material (not shown)
Inject. As a result, the grout material passes through the injection hole 22 and fills the gap between the outer peripheral surface of the screw reinforcing bar 10 and the inner peripheral surface of the joint 20.

The connection of the two threaded reinforcing bars 10 is completed by the hardening of the grout material. When inspecting the connection state at a later date, by seeing that both ends of the joint 20 are located between the marking grooves 14 and 16 of the respective screw reinforcing bars 10, the screwing depth of the two screw reinforcing bars 10 is determined. It can be confirmed that the required amount has been secured.

FIG. 2B shows a case where not only the joint 20 but also a pair of lock nuts 30 are used to connect the threaded reinforcing bar 10. After the ends of the two threaded rebars 10 are screwed to the joint 20, the lock nut 30 previously screwed to the threaded rebar 1 is advanced to both ends of the joint 20, and tightened with torque. When the lock nut 30 is used, the rattling between the screw reinforcing bar 10 and the joint 20 can be eliminated without causing the tip surfaces 10a of the screw reinforcing bars 10 to abut each other.

As shown in FIG. 2B, the lock nut 30
When both are used, the both ends of the joint 20 cannot be used as a reference for confirming the screwing depth. This is because the lock nuts 30 are connected to both ends of the joint 20, and the marking grooves 14 and 16 formed in the screw reinforcing bar 10 are hidden by the lock nuts 30. Therefore, in this case, the two marking grooves 16, 18 are used for confirming the screwing depth based on the outer end surface 30a of the lock nut 30 as a reference. In the present embodiment, the thickness of the lock nut 30 is set to
Since the distance Dx is equal to the distance Dx between the grooves 4 and 16, the marking groove 16 used without the lock nut 30 is also used with the lock nut 30 as described above. More specifically, when the lock nut 30 is fastened to the joint 20, the outer end surface 3 of each lock nut 30 is removed.
0a is the marking groove 16, 1 of the corresponding screw reinforcing bar 10.
When it is located between 8, the thread rebar 10 can be confirmed to be screwed into the joint 20 at the required screwing depth.

As described above, the screw rebar 10 shown in FIG.
Has three marking grooves 14, 16, 18 so that the screwing depth can be confirmed both when the lock nut 30 is not used and when it is used. Also, since the marking groove 16 is commonly used for two cases,
The configuration is simple, and the checking operation is also easy.

Next, another embodiment of the present invention will be described. In these embodiments, components corresponding to those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. FIG.
As shown in the figure, the screw reinforcing bar 10A according to the second embodiment is
The thickness Dy of the lock nut 30 is equal to the difference D between the distances Da and Db.
Unlike x, it is used for larger values. More specifically, the screw reinforcing bar 10A has marking grooves 14 and 16 used when connecting without using a lock nut, as in the first embodiment. In the threaded reinforcing bar 10A, the non-threaded portion 12 further has two marking grooves 17,
19 (third and fourth marking recesses).
The sectional shapes and the manner of forming these marking grooves 17 and 19 are the same as those of the marking grooves 14 and 16. The marking groove 17 is separated from the tip end surface 10a by a distance Dm, and is separated from the marking groove 14 by the thickness Dy of the lock nut 30. Similarly, the marking groove 19 is provided on the tip surface 10a.
From the marking groove 16 by the thickness Dy of the lock nut 30. Marking groove 1
7, 19 are separated by a distance Dx. When connecting without the lock nut 30, the marking grooves 14, 16 are used for confirming the screwing depth as in the first embodiment. When connecting using the lock nut 30, instead of the marking grooves 16 and 18 of the first embodiment, the marking grooves 17 and 19 are used for confirming the screwing depth. Note that the illustrated distances Dx, Da, and Db have the same meanings as in the first embodiment, and a description thereof will be omitted.

As shown in FIG. 4A, the threaded reinforcing bar 10B according to the third embodiment has marking grooves 41, 42 (first and second marking recesses) extending in the non-threaded portion 12 in the axial direction. have. The formation positions of the marking grooves 41 and 42 are shifted from each other in the width direction of the non-threaded portion 12 (the circumferential direction of the screw reinforcing bar 10). In the present embodiment, one marking groove 41 is formed at the center of the non-threaded portion 12 in the width direction, and two marking grooves 42 are formed on both sides of the non-threaded portion 12 in the width direction.

The distance between one end of the marking groove 41 (the end closer to the tip surface 10a) and the tip surface 10a is Da, and the other end of the marking groove 41 (the end farther from the tip surface 10a) and the tip The distance from the surface 10a is Db. One end of the marking groove 42 (the end closer to the front end face 10a) and the other end of the marking groove 41 are axially aligned,
The distance between the other end of the marking groove 42 (the end farther from the distal end face 10a) and the distal end face 10a is Dc. These distances Da, Db, and Dc have the same meaning as in the first embodiment, and a description thereof will be omitted.

An end face of the thread 13 is parallel to the marking groove 41, and an auxiliary groove 43 is formed within the length of the marking groove 41. Similarly, thread 13
An auxiliary groove 44 is formed on the end face of the mark groove 42 in parallel with the marking groove 42 and within the length of the marking groove 42.

The marking groove 41 is used for confirming the screwing depth of the screw reinforcing bar 10B when the lock nut 30 is not used. That is, if both ends of the joint 20 are located at the positions corresponding to the marking grooves 41 of the double-threaded reinforcing bar 10B, the double-threaded reinforcing bar 10B has a required screwing depth. When the lock nut 30 is used, the marking 42 groove is used to confirm the screwing depth of the screw reinforcing bar 10B. That is, if the outer end surface 30a of the lock nut 30 is located at a position corresponding to the marking groove 42, the two screw rebars 10B have secured the required screwing depth. In the present embodiment, it is assumed that the thickness of the lock nut 30 is equal to the distance Dx. The auxiliary grooves 42 and 43 are used to assist in confirming the screwing depth to facilitate the confirmation.

When the marking grooves 41 and 42 and the auxiliary grooves 43 and 44 are to be imprinted on the screw reinforcing bar 10, the engraving member has main projections corresponding to the marking grooves 41 and 42, and these main projections and Each has a parallel auxiliary projection. These auxiliary projections have the same length as the main projection. At the time of engraving, the main convex portion is pushed into the non-threaded portion 12 to form marking grooves 41 and 42, and a part of the auxiliary convex portion is pushed into the end face of the screw thread 13, and the auxiliary groove 4 is formed.
2, 44 are formed.

The threaded reinforcing bar 10C of the fourth embodiment shown in FIG. 4B is the same as the third embodiment shown in FIG. 4A except that the marking grooves 41 and 42 are separated in the axial direction. It is. In this embodiment, similar to the second embodiment in FIG. 3,
The thickness Dy of the lock nut 30 is equal to the difference D between the distances Da and Db.
Unlike x, it is assumed that it is larger than this.

The threaded reinforcing bar 10D according to the fifth embodiment shown in FIG.
In FIG. 2, marking grooves 41 and 42 are formed one by one. Others are the same as FIG. 4 (B). When the thickness of the lock nut 30 is equal to the distance Dx, one end of the marking groove 42 closer to the front end face 10a and the marking groove 41
One end farthest from the distal end surface 10a of the pair coincides in the axial position.

In all the embodiments described above, the marking groove may not be continuously extended, but may be constituted by a large number of concave portions arranged on a straight line at short intervals. The marking recess may be formed on both non-threaded portions. When the screw rebar is screwed into the joint with a large torque and the tip surfaces of the screw rebar are strongly pressed against each other, the grout material may not be used. Similarly, when the lock nut is tightened with a large torque to the joint, grout need not be used. When the lock nut is strongly tightened, the required screw length of the threaded rebar to the joint may be shorter than the required screw length when the lock nut is not used.
Furthermore, if only the case where a lock nut is used is assumed, a marking concave portion (represented in the first embodiment) indicating a required screw length of the screw rebar to the joint and the lock nut and a length prohibiting further screwing. Marking groove 14,1
6, only the marking tracks 17, 19 in the second embodiment, and the marking grooves 42) in the third, fourth, and fifth embodiments may be formed.

[0029]

As described above, according to the first aspect of the present invention, since the marking is formed by the concave portion formed in the non-threaded portion of the threaded reinforcing bar, the marking can be eliminated even if left in a severe environment. Absent. Further, the formation of the marking concave portion is simpler and more accurate than the case where the marking is performed by applying a paint, and the productivity can be improved. In addition, since the marking recesses can be formed in the production line of the screw rebar, productivity can be further improved in this manner. According to the second aspect of the present invention, the marking groove representing the required screwing length is hidden, and the necessary screwing length can be confirmed on condition that another marking groove is exposed, so that the checking operation is simple. Becomes According to the third aspect of the present invention, it is possible to check the screwing depth when there is the lock nut and when there is no lock nut.
In addition, since three marking grooves are required, the checking operation is easy. According to the fourth aspect of the present invention, the screwing depth can be confirmed regardless of the presence or absence of the lock nut without being restricted by the thickness of the lock nut. According to the fifth aspect of the present invention, the marking recess extends in the direction orthogonal to the axial direction, so that it is easy to see. According to the invention of claim 6,
The marking groove extending in the axial direction allows confirmation of the screwing depth. According to the seventh aspect of the present invention, it is possible to confirm the screwing depth when there is the lock nut and when there is no lock nut. According to the invention of claim 8, the confirmation operation can be assisted by the auxiliary groove.

[Brief description of the drawings]

FIG. 1 shows a screw reinforcing bar according to a first embodiment of the present invention,
(A) is a side view, (B) is a plan view also showing a method of forming a marking groove.

2A and 2B show a connection state of a screw rebar, in which FIG. 2A shows a state in which a screw rebar is connected only with a joint, and FIG. 2B shows a state in which the screw rebar is connected with a joint and a lock nut.

FIG. 3 is a side view of a screw rebar according to a second embodiment of the present invention.

FIGS. 4A and 4B are side views of screw rebars according to third and fourth embodiments of the present invention, in which marking grooves are indicated by hatching for easy understanding of the drawings.

FIG. 5 is a side view of a screw reinforcing bar according to a fifth embodiment of the present invention.

FIG. 6A is a side view showing marking of a conventional screw reinforcing bar, and FIG. 6B is a side view showing a connection state of two screw reinforcing bars.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Screw reinforcement 11 Thread forming part 12 Non-thread part 13 Thread 14, 16, 18 Marking groove (first, second, third marking concave part) 17, 18 Marking groove (third, fourth marking concave part) 20 Joint 30 Lock nut 41, 42 Marking groove (first and second marking recesses) 43, 44 Auxiliary groove

Claims (8)

[Claims] 1. A threaded rebar connected by screwing an end to a joint, wherein at least one of a pair of non-threaded portions extending in the axial direction has a position separated by a required screwing length from a distal end surface. A threaded rebar having a marking recess formed thereon. 2. The marking concave portion is formed as a first marking concave portion at a position separated by a required screw length from the distal end surface, and the non-thread portion further includes a first marking concave portion. The screw reinforcing bar according to claim 1, wherein a second marking recess is formed at a position separated from the recess by a predetermined distance in a direction opposite to the tip surface. 3. The non-threaded portion further includes a third marking recess formed at a position away from the second marking recess by the predetermined distance in a direction opposite to the tip end surface. The screw reinforcing bar according to claim 2, wherein 4. The non-threaded portion further includes a first threaded portion at a position apart from the first marking recess by a thickness of a lock nut disposed at both ends of the joint in a direction opposite to the tip end surface. The screw reinforcing bar according to claim 2, wherein a third marking recess is formed, and a fourth marking recess is formed at a position away from the third marking recess by the predetermined distance. 5. The threaded reinforcing bar according to claim 1, wherein the marking recess comprises a marking groove extending in a direction perpendicular to the axial direction. 6. The marking recess includes a marking groove extending over a predetermined length in the axial direction, and one end of the marking groove closer to the distal end surface represents a position separated by the required screwing depth. The screw reinforcing bar according to claim 1, wherein: 7. The marking groove is provided as a first marking groove, and a second marking groove is formed in the non-threaded portion as a second marking recess extending over the predetermined length in the axial direction. The first and second marking grooves are displaced from each other in the circumferential direction, and one end of the second marking groove, which is closer to the tip end surface, is provided at both ends of the joint from the one end of the first marking groove. 7. The threaded reinforcing bar according to claim 6, wherein the nut is separated from the tip surface in a direction opposite to the thickness by a thickness of the nut. 8. An end face of a thread continuous with the non-threaded portion, an auxiliary groove extending parallel to the marking groove is formed within a range of the length of the marking groove. The threaded rebar according to the above.