JPH08218555A - Mortar-filling type reinforcing bar joint sleeve - Google Patents

Abstract

PURPOSE: To perform reliable positioning of a sleeve by a method wherein a joint sleeve having a plurality of annular peripheral protrusions is formed in a tubular body and an reinforcing bar insertion port in which a jig is inserted is formed in the end face of the sleeve. CONSTITUTION: A plurality of inner peripheral protrusions 13 and 14 are integrally formed on the inner part of a cylindrical sleeve body 10 from the right and the left toward a central part and reinforcing bar insertion ports 11 are formed in two end faces 16 in an axial direction. When the sleeve body 10 is then attached to forms 20 and concrete is poured, one end face 16 is adhered on the inner surface of the forms 20 and a jig 21 is fitted in the reinforcing bar insertion port 11. The length of the shaft in an axial direction of the reinforcing bar insertion port 11 is set to approximate 4-6mm and increased to a value 1-3mm longer than those of the inner peripheral protrusions 13 and 14. This constitution, since a contact area is wide, improves holding ability of the right angles of the sleeve body with the inner surface of the forms.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a reinforcing bar insertion opening of a mortar-filled type reinforcing bar joint sleeve used for precast concrete building materials.

[0002]

2. Description of the Related Art Mortar-filled rebar joint sleeves for joining rebars in precast concrete building materials
It is known from 61422. The known sleeve is made of ductile cast iron, and has a tubular main body having outer diameters equal to or smaller than the central portion at both ends, rebar insertion openings provided at both end faces of the main body, and integrally formed inside the main body. And a plurality of annular inner peripheral projections formed therein, and the axial width of the reinforcing bar insertion opening was the same as the axial width of the inner peripheral projections inside thereof.

[0003]

When the sleeve is attached to the formwork and concrete is poured, a jig is attached to the rebar insertion port in order to maintain the posture of the sleeve and prevent the slag from flowing into the inside. Place the end surface of the sleeve in close contact with the inner surface of the frame. However, since the axial width of the conventional rebar insertion port is 4 mm or less like other inner peripheral protrusions, the contact area with the jig was relatively small. For this reason, there is a problem that not only is it difficult to fix the sleeve with a jig, but also it is impossible to effectively prevent the inflow from the reinforcing bar insertion port of the slag.

The present invention has been made to solve this problem, and its purpose is to make sure that the sleeve is positioned and fixed securely when the jig is fitted in the frame so that it can be sewn when pouring concrete. An object of the present invention is to provide a sleeve having a reinforcing bar insertion port capable of effectively preventing the inflow of iron.

[0005]

In order to achieve the above object, the means adopted by the present invention is such that the axial width of the reinforcing bar insertion opening of the sleeve body is 1 to 3 m more than the axial width of other inner peripheral projections.
m longer, specifically, the axial width of the rebar insertion port is 4
It is about 6 mm.

[0006]

The sleeve of the present invention has a relatively large width in the axial direction of the reinforcing bar insertion port, so that the contact area with the jig fitted therein is wider than before. As a result, there is almost no gap between the jig and the jig, and when the jig is fitted into the reinforcing bar insertion hole, the main body is reliably positioned and maintains the right angle with respect to the inner surface of the frame. Alternatively, since the contact area between the jig and the reinforcing bar insertion port is large, there is less risk that the slag will flow from the reinforcing bar insertion port during precasting. Also, when a tensile load is applied to the sleeve, the ring tension, that is, the circumferential stress, becomes maximum at the end of the main body, but since the axial width of the rebar insertion port was lengthened,
The ends are reinforced and the safety against tensile load is improved.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The sleeve of the present invention will be described based on the embodiments shown in the drawings. The cylindrical sleeve body 10 shown in FIG. 1 is made of ductile cast iron, and the reinforcing bar insertion ports 11 and 12 are provided on both end surfaces 16 and 17 in the axial direction. Although not shown, mortar inlets and outlets are provided at both ends. Inside the main body 10, a plurality of annular inner peripheral projections 13, 14, 15 are integrally formed from the left and right sides in the center.

As shown in FIG. 2, the inner circumferential projections 13 and 14 have an axial width of 3.0 to 3.5 mm. When the main body 10 is attached to the formwork 20 and concrete is poured, one end face 16 is brought into close contact with the inner face of the formwork 20, and the reinforcing bar insertion port 11 passing through the end face 11
The jig 21 is fitted to the. The axial width of the rebar insertion port 11 is 4
It is ~ 6 mm, and is 1 to 3 mm longer than the inner peripheral projection. When the jig 21 is fitted into the rebar insertion opening 11, the contact area is wide and the fitting is firm, so the main body 10 is reliably positioned, and the sleeve 10 maintains the right angle to the form 20 even during concrete pouring. To do. In addition, since the jig 21 and the reinforcing bar insertion port 11 are tightly fitted to each other, there is little possibility that slag will flow into the precast.

In the embodiment, the both ends in the axial direction are sleeves having the same outer diameter as the central portion, but the present invention can be applied to a sleeve having a truncated cone shape on one side or both sides.

[0010]

As described above, according to the sleeve of the present invention, unlike the conventional one in which the axial width of the reinforcing bar insertion port is 4 mm or less, the axial width of the reinforcing bar insertion port is 4 to 6 mm. When the tool is inserted into the reinforcing bar insertion opening, the contact area is wide, so the right-angled holding property of the sleeve main body with respect to the inner surface of the frame is improved, and the inflow of slag when pouring concrete is prevented,
Further, it has an excellent effect that the strength of the sleeve body against the ring tension is also improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of a sleeve of the present invention,

FIG. 2 is an enlarged view showing a main part of the sleeve of FIG.

[Explanation of symbols]

 10: Main body, 11, 12: Reinforcing bar insertion port, 13, 14, 15: Inner peripheral projection, 16, 17: End surface, 20: Form frame, 21: Jig

Claims (1)

[Claims] 1. A tubular main body (10) having an outer diameter which is the same as or smaller than the central portion at both axial ends, and a reinforcing bar insertion port (11) provided on the end faces (16, 17) of the both end portions. , 12),
A plurality of annular inner peripheral protrusions (1
3, 14, 15) of the cast iron sleeve, the axial width of the reinforcing bar insertion port (11) provided on the end face (21) that is in close contact with the inner surface of the form when concrete is placed is A mortar-filled rebar joint sleeve, characterized in that it is formed to be 1 to 3 mm longer than the axial width of the protrusions (13, 14, 15).