JP2001254481A - Joint structure of reinforcing bar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joint structure of a reinforcing bar which is inexpensive and excellent in reliability. SOLUTION: A pair of nut members 1 with a female screw 1a formed on an inner circumferential surface thereof are joined with each other by the friction welding, a screw portion (a tip) 2A with a male screw 2a on an outer circumference is joined with a tip of a reinforcing bar body 2B by the friction welding, and the reinforcing bar with the male screw 2a formed thereon is inserted from both sides of the nut member 1 to be screwed in the female screw 1a of the nut member 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure of a reinforcing bar arranged on a concrete structure or a foundation, and more particularly to a joint structure of a reinforcing bar with a lock function which can be supplied at low cost.

[0002]

2. Description of the Related Art Conventionally, a joint structure of a reinforcing bar arranged on a structure such as reinforced concrete includes a nut member screwed from the center into a left-handed screw and a right-handed screw, and one end provided with a tip. The right-hand thread is screwed to the rebar to be connected, and the other end is screwed to the left-hand thread to be connected. Nuts were arranged and fastened so as not to loosen at the joint. Alternatively, regarding the direction of the screws, there were cases where right-handed screws or left-handed screws were used.

[0003] In any case, however, in the case of the above configuration, since an external thread is screwed into a long reinforcing bar, it becomes expensive in terms of price, and the nut member is also required from one end of the nut member. Since the right-hand thread is screwed from the other end to the left-hand thread, the processing becomes complicated and the price becomes expensive.

[0004] Accordingly, the cost of the reinforcing parts for reinforced concrete works, such as buildings, dams or road piers, which require very large amounts of these joint structures, has been considerably high.

The present invention has been made in view of such a situation, and an object of the present invention is to provide an inexpensive and highly reliable rebar joint structure.

[0006]

According to the joint structure of a reinforcing bar of the present invention, a nut member having an internal thread formed on an inner peripheral surface thereof is joined by a pair of friction welding and an outer peripheral portion of the reinforcing member is frictionally welded to a tip of the reinforcing bar main body. And a threaded portion formed with a male screw is inserted into the nut member from both sides of the nut member and screwed together.

However, according to the joint structure of the reinforcing bar constructed as described above, the female screw portion can be manufactured simply and efficiently by the process of manufacturing a normal nut. However, it can be simply and efficiently manufactured by simply manufacturing ordinary bolts on short members. Also, commercially available mass-produced products can be used. Since the threaded portions (female and male threads) can be formed into a nut member or a reinforcing bar having a male thread at the tip by friction welding, respectively, it can be manufactured extremely simply and inexpensively. Moreover, because of the friction welding, the entire joining surface is melted, and extremely high reliability can be obtained at the joining portion. Also, if the melted part protrudes from the inner peripheral surface of the nut member that has been friction-welded,
It is possible to easily realize a configuration that can effectively prevent a situation in which one rebar is excessively screwed into the nut member so as to “protrude” from the center of the nut member on the opposite side.

Further, in the above-described joint structure of a reinforcing bar, an enlarged portion having an effective diameter larger than that of the other portion is formed in a portion of the male screw to be inserted into the nut member side, so that this portion is formed. As a result, the torque increases and the locking function is achieved. Therefore, the joint structure of the rebar according to this configuration does not require a lock nut.

Further, in the above-described joint structure of a reinforcing bar,
When the male screw and the female screw are round screws, the dimensional control of the screws becomes easier, so they can be manufactured at low cost.
Smooth screwing can be realized.

[0010] In the above-mentioned joint structure of a reinforcing bar, the male screws screwed from both sides of the nut member are both right-handed screws or left-handed screws. Alternatively, since the same thing can be used for both of the left-handed screws, the configuration can be implemented at lower cost due to the mass production effect.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a joint structure of a reinforcing bar according to an embodiment (example) of the present invention will be specifically described with reference to the drawings.

FIG. 1 is an overall side view, partially in section, showing a joint structure according to the present embodiment. In the figure, reference numeral 1 denotes a nut member. This nut member 1 is formed by physically two members having a female screw 1a formed of a right-hand thread on an inner peripheral surface thereof.
It is joined by friction welding at the center. In the case of this embodiment, in the friction welding portion, a part of the melted portion protrudes to the outer peripheral side of the friction welding portion. The internal thread 1a uses a round thread as a thread type. And although the said internal thread 1a is manufactured by a tap, you may manufacture by other methods. On the other hand, in FIG. 1, reference numeral 2 denotes a reinforcing bar to be connected, in which a screw 2a is screwed around an outer periphery of a tip portion (screw portion) 2A. The distal end portion 2A is integrally joined to the rebar main body 2B on the proximal end side by friction welding. The male screw 2a is a right-hand screw that is screwed to the female screw 1a.
The type of the screw is a round screw. The portion of the male screw 2a screwed to the nut member 1 is slightly dimensionally small (for example, a screw having a screw diameter of about 13 mm,
(Approximately 5/100 mm to 1/10 mm), which is not clearly shown in the drawing. However, a portion 2b having an effective diameter that is large within the extent that the female screw 1a is deformed and screwed is formed. In the case of this embodiment, the enlarged portion 2b is screwed to the nut member 1 side,
It is formed at a position where it is screwed to the outer end portion of the nut member 1. In this embodiment, the male screw 2a is manufactured by rolling.

Thus, according to the joint structure of the present reinforcing bar, the nut member 1 is manufactured by joining two physically identical members by friction welding.
The external thread 2a is formed by rolling a short member, and thereafter, the external thread is integrally joined to the reinforcing bar main body 2B side by friction welding, so that the external thread is formed by a small device (tapping device, rolling device). Therefore, it can be manufactured at low cost. Also, since the joints are joined by friction welding, the entire joint surface is melted compared to the case where they are jointly joined by ordinary electric welding etc., and extremely high strength and reliability are achieved at the "joining point". Obtainable.

In place of the above embodiment, as shown in FIG. 2, the portion of the nut member 1 which protrudes to the outer peripheral side during friction welding at the longitudinal center portion can be deleted. In such a case, the appearance becomes beautiful. In addition, by forming a portion which is intentionally melted and protruded in the friction welding on the inner peripheral surface at the center of the nut member 1, one rebar 2 is excessively screwed up to a threaded portion of the other rebar 2. It may be configured not to match.

Further, as another embodiment having an adjusting function with respect to the length of the reinforcing bar, as shown in FIG. 3, one member 1A constituting the nut member 1 is lengthened and screwed to this member 1A. When the male screw 2a to be formed has a straight diameter (the effective diameter is not increased as in the embodiment of FIG. 1) and the lock nut 3 is screwed onto the male screw 2a, the length of the reinforcing bar matches the required length of the rebar. In addition, a rebar having a male screw 2a screwed with the lock nut 3 at the tip thereof is
The structure is such that it is sufficient to screw the nut to the nut member 1 that joins the rebars, and fix it with the lock nut 3 at that position. As for the male screw 2a of one reinforcing bar as in the embodiment of FIG. 1, it is the same in that a portion 2b having a large effective diameter is formed in a part. In the embodiment of FIG. 3, the same components as those of FIG. 1 are denoted by the same reference numerals.

[0016]

According to the rebar joint structure of the present invention, it is possible to provide an inexpensive and highly reliable rebar joint structure at a low cost.

[Brief description of the drawings]

FIG. 1 is an overall side view, partially in section, showing the configuration of a joint structure of a reinforcing bar according to an embodiment of the present invention.

FIG. 2 is a partial side view showing a configuration of a nut portion according to another embodiment different from FIG.

FIG. 3 is a partially cross-sectional overall side view showing a configuration of a joint structure of a reinforcing bar according to another embodiment different from the embodiment of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Nut member 1a ... Female thread 2 ... Rebar 2A ... Tip part (screw part) 2a ... Male screw 2B ... Rebar main body

Claims (4)

[Claims] 1. A nut member having an internal thread formed on an inner peripheral surface thereof is joined by a pair of friction welding, and a screw portion having an external thread formed on an outer periphery thereof is joined to a tip of a reinforcing bar body by friction welding. A joint structure for a reinforcing bar, wherein a reinforcing bar having an external thread is inserted from both sides of the nut member and screwed together. 2. A reinforcing bar according to claim 1, wherein an enlarged diameter portion having an effective diameter larger than that of the other portion is formed in a portion of the male screw inserted into the nut member. Fitting structure. 3. The joint structure for a reinforcing bar according to claim 1, wherein the male screw and the female screw are round screws. 4. A male screw screwed from both sides of the nut member is a right-handed screw or a left-handed screw, and correspondingly, both internal threads constituting the nut member are both a right-handed screw or a left-handed screw. The joint structure for a reinforcing bar according to any one of claims 1 to 3, characterized in that: