JPH10277756A - Deformed reinforcing bar joining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enlarge joined strength and to smoothly discharge the exhaust gas generating at the time of joining by almost eliminating the bubble mixing into the iron lump around the butting part in the case of filling a molten iron into the butting part of deformed reinforcing bars to join. SOLUTION: A forming jig 1 is provided with the surrounding forming part 1a providing a space in the butting part of deformed reinforcing bars 8, the melting part 1b arranging an igniting nichrome wire 2 and the gate 3 capable of opening/closing in the bottom part and the outlet respectively, and the wave- like flowing passage extending from the melting part 1b to the forming part 1a, a part of which extending a little upward toward the downstream side and resisting the flow of the molten iron in the lower surface. The smoke discharging cylindrical body 7, providing with plural large hole nets and small hole nets and covered with a net lid, is installed in the opening end of the melting part 1b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding jig and a smoke exhaust cylinder for joining longitudinally shaped deformed reinforcing bars having printed portions (bamboo joints) used for construction of buildings such as buildings and bridges. The present invention relates to a deformed reinforcing bar joining apparatus comprising a body.

[0002]

2. Description of the Related Art The present applicant has already proposed a method of joining deformed reinforcing bars by a deformed reinforcing bar joining apparatus shown in FIG. 4 (patent application filed on March 24, 1997). The joining device is mainly composed of a molded part 1'a having a space for filling iron in a molten state and aluminum powder and iron oxide powder, or iron powder, aluminum powder and iron oxide powder. A molding jig 1 'comprising a molten portion 1'b for injecting molten iron into the molded portion 1'a by causing the mixed powder 6 to undergo a thermochemical reaction, and an annular projecting portion which is sequentially inclined from the bottom and inclined downward. It comprises a plurality of partition plates, a filter made of asbestos, and a smoke exhaust tube 7 'fitted to the open end of the fusion zone 1'b.

[0003] The joining of deformed reinforcing bars using this joining apparatus is as follows.
This is performed as follows. That is, by energizing the nichrome wire 2 arranged at the bottom of the melting portion 1'b and igniting from below, the mixed powder 6 is brought into a molten state, the disc pad 9 is melted, and the molten iron separated at the lower portion is formed. The space of the molding part 1'a is filled. After cooling, the forming jig 1 'is removed to join the deformed reinforcing bars.

[0004]

The joining of deformed reinforcing bars by the above-mentioned joining apparatus is an epoch-making one which succeeds in greatly reducing bubbles mixed in an iron lump surrounding a butt portion. In addition, since the flow of the molten iron from the molten portion 1'b of the molding jig 1 'to the molding portion 1'a is too fast, bubbles of several percent are mixed in, which is not preferable in terms of tensile strength. Moreover, in the above-mentioned smoke exhaust tube 7 ', it was difficult to discharge gas generated by the thermochemical reaction smoothly due to the plurality of downwardly inclined partition plates acting as resistance.

According to the present invention, when joining the butt portions of deformed reinforcing bars with molten iron, the bubbles mixed into the iron lump surrounding the butt portions are almost eliminated, the joining strength is increased, and the joining strength is increased. The purpose is to smoothly discharge the exhaust gas generated at the time.

[0006]

According to the present invention, there is provided a molding jig comprising: a molding portion 1a for surrounding a butt portion of deformed reinforcing bars 8 with a space; a nichrome wire 2 for ignition at a bottom portion; A melting portion 1b on which the respective gates 3 are arranged;
It comprises a flow path from the melting part 1b to the forming part 1a.

[0007] A part 1d of the flow path extends slightly upward to the downstream side, and its lower surface is wavy giving resistance to the flow of the molten iron.

It is more effective to make the cross sectional area of the inclined flow path 1d larger than that of the hanging flow path 1c.

The smoke exhaust cylinder according to the present invention is provided with a plurality of large-hole nets 7b having a plurality of relatively large holes at intervals, and a small hole having a large number of relatively small holes drilled thereabove. A net body 7c is provided, and a net lid 7d is put on the upper end,
It is attached to the open end of the fusion part 1b of the molding jig 1.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a deformed reinforcing bar joining apparatus according to the present invention will be described with reference to FIGS.

[0007] This deformed reinforcing bar joining apparatus is for joining butted portions of deformed reinforcing bars 8 and 8 by employing a molecular welding method utilizing a thermochemical reaction. And a melting portion 1b in which an ignition nichrome wire 2 and an openable gate 3 are disposed at a bottom and an outlet, respectively, and flow paths 1c and 1d communicating from the melting portion 1b to the forming portion 1a. It is constituted by a molding jig 1 made of a gas, and a flue gas cylinder 7 fitted to the open end of the melting portion 1b of the molding jig 1.

The molding jig 1 is made of a heat-resistant material such as graphite or wood ceramic, and is vertically divided into two members. In each case, a bolt is inserted into the bolt insertion hole 1f and tightened by a nut to be integrated. In the integrated state, a thermoforming reaction is carried out by surrounding the butted portion of the deformed reinforcing bars 8, 8 and providing a molded portion 1 a having a space for filling the molten iron and a mixed powder (Tacauerd powder) 6. The molten portion 1b to be melted and the molten iron from the molten portion 1b to the forming portion 1a
Flow paths 1c and 1d are formed.

The central portion of the molded portion 1a has a large diameter, and both sides thereof have smaller diameters toward the ends. And
An exhaust hole 1e for releasing air when molten iron flows in is provided near the upper end, and a seal member 5 made of paper clay or the like having an inner diameter substantially equal to the outer diameter of the deformed reinforcing bar 8 to be joined is provided near the lower end. It can be put in. This sealing member 5
Is for preventing molten iron from leaking.

The melting section 1b has a space for accommodating the mixed powder 6, and a gate 3 which is opened and closed by an air cylinder 4 is provided at the bottom outlet in place of the conventional disk pad. The nichrome wire 2 is connected to an external power source through a small hole 1h provided near the outlet. If necessary, a small amount of magnesium powder is added as an ignition agent.

The flow path comprises a hanging flow path 1c extending substantially vertically below the bottom outlet of the melting portion 1b, and a slant flow path 1d extending slightly upward from the lower end toward the forming portion 1a. The lower surface of the flow path 1d is wavy starting from a position slightly away from the lower end of the hanging flow path 1c. A smooth radius is formed at each of the bent portion and the outlet portion of such a flow path to ensure a smooth flow of the molten iron and prevent entrapment of bubbles due to turbulence.
When such a flow path configuration is adopted, the flow velocity of the molten iron flowing down from the hanging flow path 1c is weakened by the resistance due to the wavy bottom surface of the inclined flow path 1d, and during this time, the slightly contained air bubbles are removed from the molten iron. It is released, proceeds to the outlet side along the upper surface of the inclined flow path 1d, and is discharged from the gap with the deformed reinforcing bar 8 at the upper end of the formed portion 1a or the exhaust hole 1e.

In order to more effectively reduce the flow rate of the molten iron in the inclined flow passage 1d, as shown in FIG. 3, the width of the inclined flow passage 1d is made larger than the inner diameter of the drooping flow passage 1c. It is better to increase the area.

As the mixed powder 6 to be put into the melting portion 1b, a powder having no moisture is preferably used, and then the powder is hermetically sealed with a plastic thin film so as not to absorb moisture. The mixed powder 6 contains aluminum powder (Al) and iron oxide (Fe ₂ O).
₃ ) A powder mainly composed of powder or a powder mainly composed of iron powder, aluminum powder and iron oxide powder is used. In any case, 3000 ° C due to thermochemical reaction by heating
Raise the temperature to about. Then, in a short time, the aluminum is oxidized into alumina (Al ₂ O ₃ ) and separated from the molten iron. Since the mixed powder 6 gradually melts from the lower part to the upper part, the alumina is also gradually formed from the lower part to the upper part and does not exist as a solidified layer on the surface layer as in the conventional case. Most of the trapped air can easily escape upwards. Since the specific gravity of the molten iron is higher than that of the alumina, the molten iron is gathered downward and flows into the vertical flow channel 1c and the upward flow channel 1d. In addition, 1g in FIG. 1 is a hole for inserting a slip-preventing knock pin when the two-piece molding jig 1 is integrated.

The flue gas cylinder 7 is made of iron, and is subjected to a thermochemical reaction by heating the mixed powder 6 contained in the melting portion 1b.
This is to prevent the powder from exploding and scattering with the flame. At its lower end, a frame 7a to be fitted to the open end of the fusion zone 1b of the molding jig 1 is attached. Inside, a plurality of large-hole nets 7 in which a number of relatively large holes (for example, 2 mm in diameter) are drilled from the bottom.
b, a small hole net 7c provided with a number of relatively small holes (for example, 0.5 mm in diameter) is provided. The uppermost end is covered with a mesh lid 7d in which a number of relatively small holes are formed. By adopting such a configuration, the smoke exhaust cylinder 7 can effectively prevent the rise of the flame and the scattering of the dust, and can smoothly discharge the gas generated by the thermochemical reaction.

Next, a procedure for joining deformed reinforcing bars by the joining apparatus of the present invention will be described.

First, the deformed reinforcing bars 8, 8 are butted together, and two members forming the forming jig 1 are bolted so that the butted portion is surrounded by the forming portion 1a. Next, the hermetically sealed package of the mixed powder 6 is put into the melting portion 1 b, the smoke exhaust cylinder 7 is fitted to the open end thereof, and the Nichrome wire 2 is energized. At this time, the gate 3 is in a closed state. The heat generated by the nichrome wire 2 causes the mixed powder 6 to undergo a thermochemical reaction to form a mixed melt. At that time, the aluminum is oxidized to become alumina, and is separated from the molten iron. Molten iron occupies the lower position because of its high specific gravity. Then, when the gate 3 is opened, the molten iron flows down from the hanging flow path 1c, and the flow velocity is weakened by the resistance due to the wavy bottom surface of the inclined flow path 1d.
Slightly contained air bubbles are released from the molten iron, proceed to the outlet side along the upper surface of the inclined flow path 1d, and are discharged from the gap with the deformed reinforcing bar 8 at the upper end of the formed portion 1a or the exhaust hole 1e. When the molten iron flows into the molded portion 1a and is filled up, and the temperature is lowered, the molten iron is welded by molecular welding to form an integrated structure surrounding the deformed reinforcing bars 8,8. Finally, the smoke exhaust tube 7 and the molding jig 1 are removed, and the process ends. The number of bubbles in the iron lump constituting this structure is reduced to almost zero. Therefore, the tensile strength is further increased.

[0017]

Since the present invention is configured as described above, it has the following effects.

That is, since a part of the flow path is extended slightly upward to the downstream side, and the lower surface is formed in a wavy shape which gives resistance to the flow of the molten iron, it is mixed in the iron lump surrounding the butted portion of the deformed reinforcing bar. Bubbles can be reduced to almost zero, and the expected maximum bonding strength can be obtained. Further, it is possible to prevent the rise of the flame and the scattering of the dust caused by the joining operation of the deformed reinforcing bars, and it is possible to smoothly discharge the gas generated by the thermochemical reaction. Furthermore, since a gate is provided at the exit of the melting portion to allow iron to flow down in a completely molten state, contamination of impurities can be prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a molding jig of the present invention.

FIGS. 2A and 2B are diagrams of a flue gas cylinder according to the present invention, in which (1) is a longitudinal sectional view of the entirety, (2) is a longitudinal sectional view of a large hole mesh, (3) is a longitudinal sectional view of a small hole mesh, 4) is a longitudinal sectional view of the mesh lid.

FIG. 3 is a perspective view of a flow path of the molding jig of the present invention.

FIG. 4 is a longitudinal sectional view of a conventional molding jig.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Molding jig 1a Molding part 1b Melting part 1c Hanging flow path 1d Inclined flow path 2 Nichrome wire 3 Gate 6 Mixed powder 7 Smoke exhaust cylinder 8 Deformed bar

Claims (4)

[Claims] 1. A molded part surrounding a butted part of deformed reinforcing bars by providing a space, a nichrome wire for ignition at the bottom and a gate capable of opening and closing at an outlet, and a molten part from the molten part to the molded part. A molding jig consisting of a flow path. 2. The molding jig according to claim 1, wherein a part of the flow path extends slightly upward to the downstream side, and the lower surface is wavy giving resistance to the flow of the molten iron. 3. The molding jig according to claim 2, wherein the cross-sectional area of the inclined flow path is larger than the cross-sectional area of the hanging flow path. 4. A plurality of large-hole nets having a plurality of relatively large holes formed therein are provided at intervals, and a small-hole net having a plurality of relatively small holes formed therein is provided above the large-hole nets. To
A flue gas cylinder covered with a mesh lid and attached to the open end of the melting part of the molding jig.