JPH0629323Y2 - Different diameter joint for threaded joint bar - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a joint used for connecting a threaded joint bar used in a concrete structure, and particularly to a large diameter threaded joint bar and a slightly smaller diameter. The present invention relates to a joint having a different diameter used for joining with a small-diameter screw joint rebar.

[Prior Art] Generally, when a concrete structure is made, depending on the scale of the structure, as the concrete structure moves from the low-rise part to the high-rise part, the reinforcing bars used in the structure gradually increase in diameter from large diameter. The size has been changed to a smaller diameter. And, the same construction is also applied to the threaded joint bar.

By the way, in the case of the above-mentioned thread-bar reinforcement, the conventional method of joining is the gas pressure welding method or the mechanical joint (hereinafter referred to as joint) construction method. However, due to the decrease in the number of pressure welding engineers and the weather, there are many problems in terms of workability and construction period. Therefore, in recent years, instead of this gas pressure welding method,
Since the joint can be rotated and joined, work can be performed without requiring skill, and the latter construction method, which greatly contributes to workability and shortening of the construction period, is being widely used. And
The joint used in this construction method has a female screw, which fits the male screw of the screw edge rebar, formed on its inner peripheral surface.

[Problems to be solved by the device]

By the way, in this type of joint, it is a joint with a different diameter that joins a large-diameter threaded knot rebar and a small-diameter threaded knot rebar, and a small-diameter threaded knot rebar with a dimensional difference that interferes with the female screw Different diameter joint having a female thread on the side, in other words, the outer diameter of the threaded joint of the small diameter threaded joint bar is between the outer diameter of the threaded joint of the large diameter threaded joint bar and the root diameter. The different-diameter joint for joining the large-diameter screw-bar reinforcement and the small-diameter screw-bar reinforcement has female threads with different screw diameters processed on the small-diameter side and the large-diameter side, with the approximate center of the joint as the boundary. When using this joint, one of the screw rebars must be rotated to join, but if the screw rebar is long or large in diameter and heavy, or if the screw rebar is bent, If it hits the rebar next to it, it cannot rotate.

On the other hand, as described above, in the joint where the diameter difference between the large diameter female screw and the small diameter female screw is small, when the small diameter female screw is cut through the large diameter female screw, the valley of the small diameter female screw is Since it scrapes off the pile of the large-diameter female screw, in the state where the joints of the threaded joints required for this type of joint are joined together, a tensile force that is about the tensile strength of the base material of the small-diameter jointed joints is applied. In case,
It is considered that it is not possible to exceed the restrictions such as the fact that the threaded joint bar does not come off from the joint and the joint does not break. Therefore, this type of different-diameter joint for threaded joint bar has not been put into practical use.

[Means for Solving the Problems]

The present invention has been made to solve the above problems,
The gist thereof is a large-diameter female screw portion for joining a large-diameter screw-bar reinforcing bar and a small-diameter screw-bar reinforcing bar having an outer diameter smaller than the outer diameter of the large-diameter screw-bar reinforcing bar and larger than the valley diameter. And a small-diameter female screw portion with a substantially central portion in the longitudinal direction as a boundary, wherein the female screw of the small-diameter female screw portion is provided through the large-diameter female screw portion. It is a joint with different diameter.

[Action]

In this different-diameter joint, the female screw of the small-diameter female screw portion is processed through the large-diameter female screw portion, so the small-diameter screw section rebar is screwed in from the small-diameter female screw portion side of the different-diameter joint, and then, The large diameter threaded knot reinforcing bar can be joined to the small diameter threaded knot reinforcing bar only by bringing the large diameter knotted knot reinforcing bar close to the small diameter knotted knot reinforcing bar and screwing back the different diameter joint.

Further, since the large diameter threaded knot rebar and the small diameter threaded knot rebar to be joined in this way are not necessarily the ones having the same lead angle of the threaded knots or those having the same screw pitch, processing of different diameter joints The groove width of at least one of the small-diameter female screw portion and the large-diameter female screw portion is preferably processed to be slightly larger than the joint width of the screw joint reinforcing bar joined thereto.

[Embodiment] An embodiment according to the present invention will be described below with reference to the drawings.

In the drawing, reference numeral 1 is a joint having a hexagonal outer shape and having a large diameter female screw 4 on the left half 3 from the substantially center of the inner peripheral surface 2 and a small diameter over the entire length of the inner peripheral surface 2. The female screw 5 is provided by being cut on the same core. Reference numeral 6 denotes a portion in which a ridge 7 of the large-diameter female screw 4 cut earlier is cut out and a valley 8 of a smaller-diameter female screw 5 cut later is cut out.

A method of joining the large-diameter screw joint rebar 9 and the small-diameter screw joint rebar 10 using the different diameter joint 1 will be described with reference to FIGS. 2 to 5.

: A lock nut 11 and a different-diameter joint 1 are screwed into the small-diameter screw-joint rebar 10 of the two screw-joint rebars 9 and 10 to be joined in this order and from the small-diameter female screw side of the different-diameter joint 1. The end surface of the different diameter joint 1 and the end surface of the small diameter screw joint rebar 10 are set to be substantially flush with each other. (See FIG. 2): A lock nut 12 is screwed into the large-diameter screw joint rebar 9 up to the marking position 13. (Refer to FIG. 3): The two joints of the screw joints 9 and 10 to be joined are opened at a slight interval of about the difference in the number of pitches of the left and right female screws of the different-diameter joint 1, and the shaft centers are aligned. The screw is returned from the small-diameter screw bar reinforcing bar 10 until it abuts on the lock nut 12 of the large-diameter screw bar reinforcing bar 9. (See FIG. 4): After that, tighten the lock nuts 11 and 12 on both sides of the different-diameter joint 1 until they come into close contact with the end surface of the different-diameter joint 1.
(Refer to Fig. 5) As described above, using a different-diameter joint in which a large-diameter female screw part is processed with a small-diameter female screw, a large-diameter screw rebar with an outer diameter of 38 mm and a small-diameter screw rebar with an outer diameter of 35 mm are used. As a result of performing a tensile test on the five joints, the male screw part did not come off from the different diameter joint, and there was no breakage at the female screw part of the different diameter joint. It fractured at the wood part.

[Effect of device]

As described above, by using the different-diameter joint of the present invention, it is possible to rotate the large-diameter screw reinforcing bar and the small-diameter screw reinforcing bar having a small outer diameter difference without rotating the screw joint reinforcing bar. They can be joined and have excellent workability and workability, which can greatly contribute to shortening the construction period.

[Brief description of drawings]

FIG. 1 is a partial sectional explanatory view showing a different diameter joint of the present invention,
FIGS. 2 to 5 are views for explaining a method of joining the screw joint reinforcing bars by using the different diameter joint of the present invention. 1 ... Different diameter joint, 2 ... Inner surface 4 ... Large diameter female screw, 5 ... Small diameter female screw 6 ... Notched portion, 7 ... Large diameter female screw thread 8 ... Small diameter Female thread trough, 9 …… Large diameter screw joint rebar 10 …… Small diameter screw joint rebar 11,12 …… Lock nut

Claims (1)

[Scope of utility model registration request] 1. A large-diameter female screw for joining a large-diameter screw-bar reinforcing bar to a small-diameter screw-bar reinforcing bar having an outer diameter smaller than the outer diameter of the large-diameter screw-bar reinforcing bar and larger than the valley diameter. A small diameter female screw portion, a different diameter joint having a substantially central portion in the longitudinal direction as a boundary, wherein the female screw of the small diameter female screw portion is provided through the large diameter female screw portion. A different diameter joint for threaded joint bar reinforcement.