JPH012732A - Manufacturing method for joint hardware for deformed steel bars - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a joint metal fitting used for connecting large-diameter deformed steel bars.

[Prior art]

A plurality of protrusions are formed on the inner surface of this type of joint hardware in order to increase the adhesion of the grout material filled into the gap with the deformed steel bar. As methods for forming the protrusions in conventional manufacturing methods, there are two known methods: one is to cast the entire joint hardware, and the other is to form the protrusions on the inner surface of the tube body by cutting with a lathe or the like.

[Pressure points to be solved by this invention]

However, this conventional forming method has the problem that the work is complicated and troublesome and requires skilled workers, making the joint hardware expensive.

The present invention was devised in view of the above-mentioned circumstances, and its purpose is to provide a method for manufacturing a joint metal fitting for a deformed steel bar that can easily and reliably form a protrusion formed on the inner surface.

[Means for solving problems]

According to this invention, the inner surface of the tubular section, which is divided into a plurality of pieces each having a protrusion extending toward the inner circumferential direction, is brought into contact with and pressed against the outer circumferential surface of the pipe body for joint hardware. A protrusion is formed to increase the adhesion force of the filler on the inner surface of the body.

And just by suppressing the pipe for joint hardware with the shape material, a protrusion can be easily formed on the inner surface without any skill required. An'i! Ii.

〔Example〕

The present invention will be explained below with reference to illustrated embodiments.

First, to explain the mold material 1 for carrying out the method of the present invention, the mold material 1 is formed into a tubular shape having a protrusion 2 extending in the circumferential direction on the inner surface, and is divided into four parts so as to be freely movable inside the outer puffer 3. It is provided. (See Figures 1 and 2) The moving surface 4 in the outer circumferential puffer 3 of the mold 1 is a tapered surface, and as the mold 1 moves, the diameter of the protrusion 2 increases.
The diameter can be reduced.

Next, when manufacturing the joint hardware 5 using the manufacturing method of the present invention using the mold material 1 having the above-mentioned configuration, first, the mold material 1 inside the outer circumferential puffer 3 is placed in the position shown in FIG. state. Then, a pipe body 6 for a joint hardware is inserted into this mold material 1.

Next, the mold material I is moved in the direction of the arrow in FIG. At this time, the diameter of the protruding portion 2 of the profile 1 is reduced by the action of the moving surface 4, which is a tapered surface.

As a result, the outer circumferential surface of the pipe body 6 in the mold material 1 is
, the protrusion 2 bites into the outer peripheral surface of the tube 6, and a protrusion 7 corresponding to the protrusion 2 is formed on the inner circumference of the tube 6.
is formed. (See FIGS. 3 and 4) Next, when the formation of the protrusion 7 is completed, the mold material 1 is moved to the state shown in FIG. 1, and the diameter of the protrusion 2 is expanded. Thereafter, the tubular body 6 is moved and the aforementioned protrusion 7 forming operation is performed again.

By repeating these operations one after another, a plurality of protrusions 7 are formed on the inner circumferential surface, and the joint hardware 5 is completed.

(See FIG. 7) FIG. 5 shows another embodiment of the method of the present invention, in which the mold material divided into a plurality of pieces is moved in a direction perpendicular to the axis of the tube body 6, and the outer circumferential surface of the tube body 6 of the mold material 1 is This is to apply pressure to the

The shape material l here is divided into three parts, and the upper part is an outer ring 3a that moves up and down in a direction perpendicular to the axis of the tube body 6.
In addition, the lower two pieces are each attached to a fixed outer circumferential ring 3b.

Then, by moving the upper piece toward the lower two pieces, the three-divided section 1 comes into contact with and suppresses the outer peripheral surface of the tube body 6, forming a protrusion 7 on the inner circumferential surface of the tube body 6. do.

Note that each of the three parts may be moved in a direction perpendicular to the axis of the tube body 6.

3. Effects of the Invention] By abutting and suppressing a plurality of divided tubular sections each having a protrusion extending in the circumferential direction on its inner surface against the outer circumferential surface of the tube for fitting hardware, the inner surface of the tube can be suppressed. By forming the protrusion on the circumferential surface, the joint hardware can be manufactured at low cost.

In other words, it does not require skilled workers unlike conventional casting and cutting operations, and can be easily manufactured by simply pressing the mold material against the tube body. We can provide fitting hardware at low cost.

[Brief explanation of drawings]

1 and 3 are process diagrams showing the manufacturing method of the present invention, FIG. 2 is a cross-sectional view taken along line A-Aa in FIG. 1, FIG. 4 is a cross-sectional view taken along line B-B in FIG. 3, and FIG. 6 is a sectional view taken along the line C--C in FIG. 5, and FIG. 7 is a sectional view showing a joint hardware. ■...Shape material, 2...Protrusion, 3...Outer ring 3a...
Movable outer ring, 3b: fixed outer ring, 4: moving surface, 5: joint hardware, 6: pipe body 7: protrusion.

Claims (1)

[Claims] By abutting and pressing the inner surface of a plurality of divided tubular sections each having a circumferentially extending protrusion formed on the inner surface against the outer circumferential surface of a tube for fitting hardware, the filler material on the inner surface of the tube is pressed. A method for manufacturing a fitting for a deformed steel bar, characterized in that a protrusion is formed to increase adhesion.