JPS594092Y2 - Rebar joint fittings - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a reinforcing bar joint.

Generally, in the construction of reinforced concrete buildings, joints of reinforcing bars need to have strength to resist external forces such as tension and bending in order to maintain the integrity of the reinforcing bars.

BACKGROUND ART Conventionally, for connecting reinforcing bars to each other, a joining fitting has been proposed that includes a plurality of strips surrounding a joint of reinforcing bars and a pair of ring-shaped members fitted to the strips.

According to this joint fitting, the strip is configured such that the thickness gradually decreases from the center portion to both ends thereof,
By moving the ring-shaped member from both ends of the strip toward its center, the reinforcing bars are tightened and joined together.

By the way, reinforcing bars and strips generally have dimensional errors during manufacturing or processing.

For example, there may be a manufacturing error in the diameter of the reinforcing bars that causes a step when the reinforcing bars are butted against each other, or there may be a manufacturing error in the diameter of the central portion of the strip.

In such a case, there is a problem in that when reinforcing bars are joined using the joining fittings, a large pull-out resistance cannot be obtained.

This is because the central part of the strip is thicker than both ends, so the central part located at or near the end of the reinforcing bar has the least flexibility in deflection, and conversely, the central part of the reinforcing bar has the least bending deformability. The ends located farthest from the ends have the greatest flexibility in flexural deformation, and as a result, the center of the strip is able to fit in with both reinforcing bars, and there is a strong bond between the center of the strip and both reinforcing bars. However, reliable tightening cannot be achieved due to insufficient contact or a gap between the center of the strip and the reinforcing bar.
As a result, when a large tensile force is applied to the reinforcing bars, the reinforcing bars are easily pulled out from between the plurality of strips.

Therefore, an object of the present invention is to provide a joining metal fitting that can obtain a large pullout resistance even if there is a dimensional error in the reinforcing bar or the above-mentioned piece.

The reinforcing bar joint according to the present invention is characterized in that the strip is configured such that the strip increases gradually from the center toward both ends, so that the strip has the greatest deformability in the center. When moving a pair of ring-shaped members fitted to multiple strips toward the ends of the strips, the strips blend well with the reinforcing bars near the ends of the reinforcing bars and can come into close contact with them. is securely tightened to the strip.

The features of the present invention will become clearer from the following description of the illustrated embodiment. The reinforcing bar joint fitting 10 according to the present invention is suitable for use in concrete construction, as shown in FIGS. 1 and 2. It is placed at the joint of a pair of reinforcing bars 12 made of round steel that are arranged as reinforcing materials for a structure and whose ends 11 are butted against each other.

The reinforcing bar joint fitting 10 is made up of a plurality of strips 16 arranged around and in contact with the joint portion of the reinforcing bars 12, and a pair of ring-shaped members 18 fitted to the strips.

Each strip 16 is made of a metal material and has a generally arcuate cross-sectional shape.

The inner circumferential surface 20 of the strip 16 has approximately the same curvature as the outer circumferential surface 12 a of the reinforcing bar 12 .

As shown in FIG. 2, the inner peripheral surface 20 of the strip 16 is provided with irregularities 22 in the circumferential direction.

The unevenness 22 has a substantially rectangular cross-sectional shape (for example, a height of 1 mm,
width 2.5 mm) and spaced apart from each other (e.g. 2.5 mm
) are arranged.

Instead of the unevenness 22 having the shape described above, the unevenness may have an arcuate cross-sectional shape or a triangular cross-sectional shape, and may be arranged in a continuous or discontinuous spiral shape or in a sawtooth shape.

The strip 16 has a wall thickness that gradually increases from a central portion 26 toward both ends 28.

By configuring the strip 16 in this way, both ends 28
As the reinforcing bar 12 moves from the center part 26 to the center part 26, it becomes easier to bend and deform, and the center part 26 located at or near the end 11 of the reinforcing bar 12 is most likely to bend and deform.

The ring-shaped member 18 is made of a metal material, and as shown in FIG. The length of the nongangular member 18 in the axial direction of the reinforcing bar 12 increases gradually.
The angle of inclination of the inner peripheral surface 30 of the strip 16 is approximately equal to the angle of inclination of the outer peripheral surface 24 of the strip 16.

The radius of the inner circumferential surface 30 of the ring-shaped member 18 is larger at one end 32 than the radius of curvature of the outer circumferential surface 24 at the central portion 26 of the strip 16 and at the other end 34
is smaller than the radius of curvature of the outer peripheral surface 24 of.

When using the reinforcing bar joint fitting 10, a pair of ring-shaped members 18 surrounding the plurality of strips 16 are moved toward the center portion 26 of the strips 16 in advance, and the plurality of strips 16 are placed at the joints of the reinforcing bars 12. They are arranged at intervals in the circumferential direction so as to surround and abut the reinforcing bars, and then, one end 32 of the ring-shaped member 18 is directed toward the end 28 side of the strip 16 (in the direction indicated by the arrow in the figure). The strip 16 is held in the disposed position by, for example, tapping the ring-shaped member 18 with a hammer, and then moved further toward the end 28 of the strip 16 using a jack or the like.

When the ring-shaped member 18 is moved toward the end 28 of the strip 16, that is, in the direction in which the wall thickness gradually increases, the thin central portion 26, which is highly flexible and deformable, is in a state where it fits well with the end 11 of the reinforcing bar. The strip 16 is in close contact with the reinforcing bar 12.
Thus, the pair of reinforcing bars 12 are securely tightened to the strip 16.

Therefore, even if there is some dimensional error in the reinforcing bars 12 or the strips 16, when an external force such as a tensile force is applied to the reinforcing bars 12, the frictional force acting between the reinforcing bars 12 and the strips 16 will be The strong connection between the reinforcing bars 12 is maintained.

Furthermore, as the strip 16 is tightened against the reinforcing bar 12, as shown in FIG. occurs.

Therefore, greater frictional resistance and shear resistance due to biting act between the reinforcing bars 12 and the strips 16 than when they are simply tightened by strips having no irregularities.

Furthermore, instead of the illustrated example, the unevenness 22 can be provided over the entire inner circumferential surface 20 of the strip 16, or it is preferable that the unevenness 22 be provided only in the central portion 26 and its vicinity, which is particularly susceptible to bending deformation. .

According to this, since the center part 26 has high bending deformability, it bites into the reinforcing bar 12 more than both end parts 28, and can obtain a larger resistance to pulling out the bow 1.

The amount of movement of the ring-shaped member 18 is determined by the amount of movement of the ring-shaped member 18.
The reinforcing bar 1 is selected as appropriate depending on the inclination angle of 4.
In order to more reliably apply the clamping force to 2, it is desirable to move the ring-shaped member 18 over the strip 16 until it yields.

The above-mentioned example relates to a case where the joining fitting 10 of the present invention is applied to joining round steel, but it can be similarly applied to joining deformed steel bars.

Furthermore, the outer peripheral surface 24 of the strip 16 and the ring-shaped member 18
The inner circumferential surface 30 can also be defined as a plane instead of the illustrated example.

According to the reinforcing bar joint according to the present invention, since the thickness of the strip gradually increases from the center to both ends,
The thin central portion, which is most easily deformed, is located around or near the ends of the pair of reinforcing bars to be joined.

Therefore, there may be manufacturing errors in the diameter dimensions of a pair of reinforcing bars, slight deformation at the ends of the reinforcing bars due to trimming of the reinforcing bars, or manufacturing errors in the center of the strip. However, the strip fits well into the reinforcing bars in its center and can securely tighten both reinforcing bars.
Thereby, it is possible to ensure a large pull-out resistance.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a reinforcing bar joint according to the present invention, and FIG. 2 is a partial vertical sectional view of the reinforcing bar joining fitting. 10: Rebar joint fitting, 11: End of rebar, 12: Rebar,
16: strip, 18: ring-shaped member, 22: unevenness, 26:
Center part of the strip, 28: end part of the strip.

Claims (1)

[Scope of utility model registration request] A plurality of strips that are arranged around and in contact with the reinforcing bars at the joints of the reinforcing bars, the thickness of which increases gradually from the center toward both ends, and the surfaces in contact with the reinforcing bars are provided with unevenness. A reinforcing bar joining metal fitting comprising a strip with a strip attached thereto, and a pair of ring-shaped members that are fitted into the strip and can tighten the strip around the strip by moving toward both ends of the strip.