JPH03290553A - Joint structure for strain threaded bar body and long nut - Google Patents

Abstract

PURPOSE:To make threads firmly connectible with each other by having a first thread opposed to a second thread whose pitch becomes smaller at a base end, and screwing such that the inner surface tip of a long nut expands its diameter into more taper form than the thread diametral size, in this thread. CONSTITUTION:Each internal thread is installed in long nuts 3, 4 and an external thread in both first and second thread reinforcement rods 1, 2 respectively, and they are oppositely set up at the specified interval. All the screw pitch is set to L1, and the external thread of the thread reinforcement rod 2 forms a second thread part whose pitch becomes smaller in proportion as going forward to a base end 2. On the other hand, the inner surface tip 31 of the long nut 3 is expanded its diameter into a more taper form than outside dimensions of the second thread reinforcement rod 2. A lock nut 4 is screwed in the first thread reinforcement rod 1 in advance, and the tip part 31 of the long nut 3 is screwed each other so as to be opposed to the second thread reinforcement rod 2 in advance, and when the long nut 3 is rotated in the direction of the second thread reinforcement rod 1, it is screwed with several thread ridges of the second thread part 9, coming into being unthreadable. Then, these thread reinforcement rods 1, 2 are clamped in a state of being pulled with each other, and further they are firmly tightened by the lock nut. With this constitution, threaded bar bodies are firmly connectible with each other through one nut.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a joint structure between a t1 tension threaded rod-shaped body such as a threaded reinforcing bar and a long nut.

[Prior Art and Problems to be Solved by the Invention] Conventionally, various joining methods have been employed, for example, in on-site joints between precast concrete floor slabs.

As one method, threaded reinforcing bars are formed protruding from the joints of the ends of the floor slabs, and a pair of said threaded reinforcing bars placed facing each other are fastened together using a predetermined joint tool such as a long nut at the site. There is a method in which a grouting agent is subsequently injected into the joint and hardened.

However, such conventional joining means have a complicated structure, such as always requiring two or more long nuts, and also have the problem that joining becomes impossible if there is a construction error between the threaded reinforcing bars. had.

Therefore, as a technology to solve the above-mentioned problems,
No. 2-13630 is disclosed.

In other words, the male thread of the second threaded rod-shaped body is formed as a first threaded portion with a predetermined number of threads at the tip having the same thread pitch as the female thread of the long nut, and the male thread following this is formed at the base end. The structure is such that a second threaded portion is formed in which the thread pitch becomes larger or smaller as it advances.

However, a tensile load acts on both the first threaded rod-shaped body and the second threaded rod-shaped body, and the second threaded rod-shaped body
A thread with a large pitch and a thread with a small pitch have completely opposite effects.

In other words, the statements in the "claims" and the "detailed description of the invention" do not match and are contradictory.

The present invention has been made in view of the above-mentioned problems,
The purpose of this is to connect all of the male threads carved into the first threaded rod and the male threads of a predetermined number of threads carved into the second threaded rod into the female threads carved into the long nut. The present invention provides a joint structure of a tension-resistant threaded rod-shaped body and a long nut that can be firmly fastened by bringing them into complete contact in the direction of tensile force.

[Means for solving problems]

The joint structure of the tension-resistant threaded rod-shaped body and long nut of the present invention is as follows:
A first threaded rod-shaped body with a male thread carved on the outer surface and a second threaded rod-shaped body
a threaded rod-shaped body and a long nut having a female thread carved therein, the male thread of the first threaded rod-shaped body and the female thread of the long nut are formed to have the same thread pitch, and the second threaded rod-shaped body The male thread of the body is formed as a first threaded portion in which a predetermined number of threads at the distal end have the same thread pitch as the female thread of the long nut, and the thread pitch increases as the subsequent male thread advances toward the base end. It is characterized in that it is formed as a second threaded portion that becomes smaller.

Further, a lock nut may be disposed adjacent to the long nut on at least one of the first threaded rod-like body and the second threaded rod-like body, or a lock nut may be disposed adjacent to the long nut, or the second threaded rod-like body The inner diameter of the second threaded rod has an inner diameter that can absorb the construction position error between the first threaded rod and the second threaded rod during on-site joining. It can also be formed so as to be larger in a tapered shape than the outer diameter of the body.

〔Example〕

Hereinafter, embodiments of the present invention will be described in more detail based on the drawings.

1 to 3 show one embodiment of the present invention, and the joint structure according to this embodiment consists of a pair of first threaded rod-shaped body 1 and second threaded rod-shaped body 2, and a long nut. 3 and a lock nut 4.

Thus, the first threaded rod-like body 1 and the second threaded rod-like body 2 are arranged facing each other with a predetermined interval, and the base ends 1a and 2a of each are buried in concrete, for example. and is in a fixed state.

In this embodiment, the first threaded rod-shaped body 1 and the second threaded rod-shaped body 2 are configured as threaded reinforcing bars with male threads carved on the outer surface, and the inner surfaces of the long nut 3 and the lock nut 4 are respectively A female thread is engraved.

Therefore, the male thread 5 of the first threaded reinforcing bar 1, the female thread 6 of the long nut 3, and the female thread 7 of the lock nut 4 are all formed to have the same thread pitch L1.

Further, in this embodiment, the male thread of the second threaded reinforcing bar 2 is formed as a first threaded portion 8 in which a predetermined number of threads at the tip end have the same thread pitch Ll as the female thread 6 of the long nut 3. At the same time, each thread pitch L2°L3. L4... is formed as a second threaded portion 9 that is gradually smaller than the threaded pitch L1.

Furthermore, the inner surface end portion 31 of the long nut 3 on the side that is screwed with the second threaded reinforcing bar 2 absorbs a construction position error between the first threaded reinforcing bar and the second threaded reinforcing bar 2 during on-site joining, which will be described later. The inner diameter of the second threaded reinforcing bar 2 is tapered larger than the outer diameter of the second threaded reinforcing bar 2 by an amount that can be increased.

Further, in this embodiment, the lock nut 4 is screwed into the first threaded reinforcing bar 1 in advance.

In this embodiment having such a configuration, at the time of construction, the lock nut 4 is first screwed onto the first threaded reinforcing bar 1 up to the base end 1a side, and then the long nut 3 is screwed onto the second threaded reinforcing bar 1.
The inner tip 31 is tapered as shown in the figure.
The whole is screwed to the first threaded reinforcing bar so that it faces the second threaded reinforcing bar 2 side.

Thereafter, as described above, the first threaded rod 1 and the second threaded rod 2 are arranged facing each other with a predetermined interval, and the base ends 1a and 2a of each are buried in concrete, for example. Keep it in a fixed state.

Next, the long nut 3 is rotated in a direction away from the first threaded reinforcing bar 1 as indicated by the arrow in FIG.

At this time, even if the first threaded reinforcing bar 1 and the second threaded reinforcing bar 2 are fixed in a positional relationship such that there is a slight construction error dimension T1 in the vertical direction in the figure, as shown in FIG. As mentioned above, since the inner surface end portion 31 of the long nut 3 is shaped to expand in a tapered shape, the female thread 6 of the inner surface end portion 31 of the long nut 3 is
It is screwed into the first threaded part 8 at the tip of the threaded reinforcing bar 2, and as the threading progresses, the position of the second threaded reinforcing bar 2 is forcibly corrected so that it is in the same axial position as the first threaded reinforcing bar. be able to.

Therefore, since the female thread 6 of the inner surface end portion 31 of the long nut 3 and the first thread portion 8 at the end of the second threaded reinforcing bar 2 have the same thread pitch as described above, there is no problem when screwing them together.
When the screwing progresses further to a position where the inner surface tip 31 of the long nut 3 screws with the second threaded part 9 of the second threaded reinforcing bar 2, the second threaded part 9 is connected to the proximal end as described above. Each screw pitch L2. L3. Since L4... is formed to be smaller than the thread pitch L1,
At the stage where the threads of the second threaded portion 9 are screwed together by two or three threads, the difference in thread pitch between the female thread 6 of the long nut 3 and the male thread of the second threaded portion 9 exceeds the allowable range. , the long nut 3 cannot be screwed in any further, and the first threaded reinforcing bar 2 and the second threaded reinforcing bar 2 are in a fixed state due to the mutual tension relationship caused by the long nut 3.

In this state, if the lock nut 4 is moved to the position where it contacts the long nut 3 and tightened as shown in FIG. 3, the first threaded reinforcing bar 1 and the second threaded reinforcing bar 2 are fixed more firmly by the long nut 3. It will be joined with.

In this way, in this embodiment, the first threaded reinforcing bar and the second threaded reinforcing bar 2 can be joined in a strong fixed state using one long nut 3 in a simple and rational manner, and the lock nut 4
By using it together, the fixed state becomes stronger.

In addition, since the inner tip 31 of the long nut 3 is shaped to expand in a tapered shape, there is a slight construction error between the first threaded reinforcing bar and the second threaded reinforcing bar 2. Even if the construction error is absorbed and the screwing progresses, the second
It becomes possible to forcibly correct the position of the threaded reinforcing bar 2 so that it is in the same axial position as the first threaded reinforcing bar 1.

Therefore, it is suitable for, for example, joints between precast concrete floor slabs, or threaded reinforcing bars at on-site joints between floor slabs and walls.

Further, the lock nut 4 may be disposed adjacent to the long nut 3 on at least one of the first threaded reinforcing bar 1 and the second threaded reinforcing bar 2, or may be disposed on both. It goes without saying that various modifications are possible without departing from the gist of the present invention, such as being able to be omitted depending on the conditions.

FIG. 4 is an enlarged cross-sectional view of the threaded part of the second threaded rod-like body 2 and the long nut 3, where the long nut 3 is pulled to the left and the second threaded rod-like body 2 is pulled to the right. However, with respect to the thread pitch L1 of the long nut 3, the second threaded rod-shaped body 2
When the thread pitch L2 is screwed together, the long nut 3 is pushed to the left and the second threaded rod-shaped body 2 is pushed to the right, and all the threads of a predetermined number of threads come into contact on the right slope.

In other words, the maximum tension of the second threaded rod-shaped body 2 and the long nut 3 can be utilized.

〔Effect of the invention〕

The present invention is constructed as described above, and includes a first threaded rod-like body having a male thread carved on its outer surface, a second threaded rod-like body, and a long nut having a female thread carved therein. The male thread of the first threaded rod-like body and the female thread of the long nut are formed to have the same thread pitch, and the male thread of the second threaded rod-like body has a predetermined number of threads at its tip end with the female thread of the long nut. By forming the first threaded part with the same thread pitch and forming the second threaded part with the thread pitch becoming smaller as the male thread that follows advances toward the proximal end, one long nut can form a threaded rod shape. It is possible to firmly join the bodies to each other, and it is possible to use a rational joining method with a simple structure and good workability.

Further, by disposing a lock nut adjacent to the long nut on at least one of the first threaded rod-like body and the second threaded rod-like body, the mutual connection between the threaded rod-like bodies becomes stronger. .

Furthermore, the inner tip of the long nut on the side that is screwed into the second threaded rod is configured to absorb a construction position error between the first threaded rod and the second threaded rod during on-site joining. By forming the inner diameter to be larger than the outer diameter of the second threaded rod-like body in a tapered manner by the amount obtained, installation errors during on-site construction can be effectively absorbed.

[Brief explanation of drawings]

1 to 4 show one embodiment of the present invention, FIG. 1 is an explanatory diagram showing each component of the joint structure of a threaded rod-shaped body and a long nut according to the present embodiment, and FIG. 2 and FIG. 3 is an explanatory view showing the construction procedure of each joint, and FIG. 4 is an enlarged sectional view of the threaded portion of the second threaded rod-shaped body and the long nut. 1: First threaded rod-shaped body (first threaded reinforcing bar) 1a: Base end portion 2: Second threaded rod-shaped body (second threaded reinforcing bar) 2a: Base end portion 3: Long nut 4: Lock nut 5: Male thread 6, 7: Female thread 8: First threaded part 9: Second threaded part

Claims (3)

[Claims] (1) A first threaded rod-like body with a male thread carved on the outer surface, a second threaded rod-like body, and a long nut with a female thread carved on the inside, the male thread of the first threaded rod-like body The female thread of the long nut is formed to have the same thread pitch,
The male thread of the second threaded rod-shaped body is formed as a first threaded portion in which a predetermined number of threads at the distal end have the same thread pitch as the female thread of the long nut, and the male thread following this is formed at the proximal end. A joint structure of a tension-resistant threaded rod-shaped body and a long nut, characterized in that the joint structure is formed as a second threaded part in which the thread pitch becomes smaller as the thread progresses. (2) The tension-resistant threaded rod-like body according to claim 1, wherein a lock nut is disposed adjacent to the long nut on at least one of the first threaded rod-like body and the second threaded rod-like body. Long nut joint structure. (3) The inner tip of the long nut on the side that is screwed into the second threaded rod prevents a construction position error between the first threaded rod and the second threaded rod during on-site joining. The tension-resistant threaded rod-like body and long nut according to claim 1 or 2, wherein the inner diameter is tapered larger than the outer diameter of the second threaded rod-like body by an amount that can be absorbed. joint structure.