JP2013173983A - Extension for flame spraying gun - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extension for a flame spraying gun capable of thermal spraying even to a narrow part.SOLUTION: This extension for a flame spraying gun is characterized in that a pipe for wire for feeding a thermal spraying wire rod, an oxygen conduit and a fuel conduit are arranged at the inside of an extension pipe having an air conduit function, further, the tip side of the extension pipe has a mixing part of oxygen and fuel, and the tip of the mixing part has the injection nozzle of a mixed gas.

Description

  The present invention relates to a thermal spray gun for thermal spraying using a gas flame, and particularly relates to an extension that enables thermal spraying of a narrow portion, which is difficult to spray with a conventional thermal spray gun.

For example, in the field of steel structures for bridges and the like, there is a demand for longer life by improving rust prevention performance.
This type of steel structure is assembled by fastening steel materials with bolts and nuts, etc., and the steel body itself has a longer life by coating with a thermal spray coating, but fastening parts such as bolts and nuts Since the frictional resistance of the sprayed surface at the time of fastening increases, tightening is not only difficult, but there are also problems such as peeling of the film and reduction of axial force due to relaxation after fastening, so coat it with a sprayed coating beforehand This is difficult, and high-strength bolts that have been galvanized have been used.
However, the galvanization alone has a problem that the corrosion resistance is remarkably inferior to that of the steel body.

Then, as shown in Patent Document 1, it has been studied to thermally spray metal onto fastening parts such as bolts and nuts on site after construction of the structure.
However, the joint of H-shaped steel or L-shaped L-shaped steel with flanges on both sides of the web is a very narrow narrow part as shown in FIG. It is necessary to spray the part, too, and it was difficult to spray with a conventional spray gun.

  Further, in Patent Document 2, the spraying direction of the spraying frame is changed, and for the purpose of suppressing the spread of the spraying frame, the tip of the spraying nozzle is used for jetting air in a direction crossing the nozzle direction. Although the technique which provided the member is shown, if such a big member is attached to the front-end | tip part of a thermal spray gun, the front-end | tip of a thermal spray gun will not enter into fastening parts, such as a L-shaped narrow part and a volt | bolt.

JP 2003-170109 A JP-A-2005-139497

  An object of the present invention is to provide an extension for a flame spray gun that can be sprayed even in a narrow portion.

  The present invention is an extension of a flame spray gun, wherein a wire pipe, an oxygen conduit, and a fuel conduit for feeding a sprayed wire material are arranged inside an extension pipe having an air conduit function, and the distal end side of the extension pipe Further, the present invention is characterized in that an oxygen / fuel mixing section and a mixed gas injection nozzle are provided at the tip of the mixing section.

Here, the extension refers to an element that is attached to the main body of the spray gun and extends the nozzle portion from the gun main body.
A pipe for wire for feeding spray wire (metal wire), an oxygen pipe for supplying oxygen, and an extension pipe for arranging and supporting a fuel pipe for supplying fuel gas such as acetylene, ethylene, propane, etc. Since it also has an air conduit function as a flow path for passing compressed air, it has an extension with a thin outer diameter.
In addition, since the mixing portion of the oxygen gas and the fuel gas is provided on the distal end side of the extension pipe, the length of the extension pipe can be freely selected, and the backflow prevention effect of the combustion flame is high.
In the present invention, the mixing portion of oxygen and fuel preferably forms a fuel gas suction port with respect to a disk-like member having an oxygen flow channel.
As described above, the aspirator function for sucking and mixing the fuel gas by the flow of the oxygen gas is given to the mixing portion, thereby obtaining a more compact and elongated structure.

The extension according to the present invention has a thin outer diameter, and the nozzle can be inserted into a narrow space.
Furthermore, in order to facilitate thermal spraying to the fastening corners such as bolts and nuts, the tip of the extension pipe has an air cap for injecting air in a direction intersecting the thermal spray frame to determine the direction of the thermal spray frame. You may do it.
If it does in this way, a jetting direction can be adjusted so that a fixed angle may be made with respect to the direction of a nozzle hole.

The gas flame spray gun using the extension according to the present invention has a thin outer diameter of the extension and a compact tip of the nozzle, so that the diameter of the gas flame spray gun is about 2.0 mm, which is thinner than the conventionally used wire diameter of 3.2 to 4.7 mm. A thermal spray wire (spray wire) having a degree (1.5 to 2.5 mm) can also be used for thermal spraying.
For example, when an Al—Mg-based or Zn—Al-based alloy wire is used as the thermal spray wire, the thermal volume can be reduced, and a thermal spray coating having a uniform and excellent adhesion can be formed.

  In addition, when an air cap that adjusts the spray direction of atomized droplets of the thermal spray material is attached to the tip of the extension pipe, uniform thermal spraying is also applied to the corners of steel structures and the fastening members such as bolts and nuts. It becomes possible.

The structural example of the extension concerning the present invention is shown. An enlarged view of the vicinity of the nozzle is shown. The structural example of the mixing part of oxygen gas and fuel gas is shown. An example of the structure of a disc-shaped mixing unit is shown. (A) is a front view, (b) is a side view, and (c) is a rear view. (D) is an ejection side disk, (e) is an inflow side disk, and (f) is an overlapping structure of two disks. The structural example of a nozzle is shown. (A) is a front view, (b) is a side view, (c) is a rear view, (d) is a cross-sectional view along line AA, and (e) is a cross-sectional view along line BB. The structural example of an air cap is shown. (A) is a front view, (b) is a side view, (c) is a rear view, (d) is a cross-sectional view, and (e) shows a spout. An example in which an extension is attached to the gas flame spray gun body is shown. Shows the state of thermal spraying on the nut.

An example of the structure of the flame spray extension according to the present invention and an example of a spray gun using the same will be described below with reference to the drawings. However, the present invention is not limited to this.
FIG. 7 shows a state in which the extension 10 is attached to the gun body 1 for gas flame spraying, and the steel material 30 is sprayed on the part joined by the bolt 31 and the nut 32.
A compressed air pipe 2, an oxygen gas tube 3 connected to an oxygen cylinder, and a fuel gas tube 4 connected to an acetylene cylinder are connected to the gun body 1, and the spray wire M is fed to the nut 32 while being fed by the wire feeder 4. The state which is spraying so that the flame | frame F may be sprayed is shown.

FIG. 1 shows a cross-sectional view of the extension 10 attached to the gun body 1, and FIG. 2 shows an enlarged view of the vicinity of the nozzle 17.
The connecting portion 19 of the extension 10 is inserted into the inside of the gun body, and is screwed to the gun body 1 with the female screw portion 20a using the joint member 20.
The front threaded portion 20 b of the joint member 20 can be screwed with a female threaded portion 11 a on the rear end side of the extension pipe 11.
In this embodiment, the inside of an extension pipe having an outer diameter of about 27 mm is arranged around the wire pipe 12 for feeding the sprayed wire M, and the fuel conduit 14 and oxygen gas for passing the fuel gas to both sides thereof. Oxygen conduits 13 for passing through were arranged in parallel.
The front ends of the fuel conduit 14 and the oxygen conduit 13 are connected to the mixing portion 15 shown in FIG.
The mixing portion 15 has a hollow portion 15n and a mixing portion for mixing fuel gas and oxygen gas. The mixing portion is formed by using two positioning plates 15j with two disk plates 15a and 15b as shown in FIG. The disc-shaped member is superposed.
The first disk plate 15a on the front end side has a mixed gas outlet 15c, and a ring-shaped groove 15i is formed between the second disk plate 15b on the rear side and the first disk 15a.
The second disk plate 15b has an oxygen gas inlet 15e and a fuel gas inlet 15d.
Oxygen gas is filled into the hollow portion 15n from the distal end portion 13a of the oxygen conduit 13.
The filled oxygen gas is supplied from the hollow portion 15n to the arc-shaped groove portion 15f through the communication hole 15g.
The arc-shaped groove 15f communicates with the inlet 15e of the second disk plate 15b.
Thus, a strong flow of oxygen gas is formed from the small diameter inlet 15e toward the first disk plate outlet 15c.
At this time, the fuel gas supplied from the tip of the fuel conduit 14 is supplied to the suction port 15d, and the oxygen gas passes through the ring-shaped groove 15i formed between the first disk plate 15a and the second disk plate 15b. Mix to be sucked in by the flow of water.
The mixed gas mixed by such an aspirator function is ejected from a nozzle 17 provided at the tip of the first gas disk via a ring-shaped groove 15h formed on the tip side of the first disk plate to form a combustion frame.
In this embodiment, four oxygen gas inlets 15e and four outlets 15c are provided concentrically, but the number is not limited.
The wire pipe 12 passes through the mixing portion while being sealed with the hollow portion 15n of the mixing portion 15, and is connected to the connection pipe 12a of the disk-shaped member.
A part of the air is sent from the outer periphery of the mixing unit 15 into the wire pipe through the air supply hole 15k.
This prevents abnormal overheating of the sprayed wire.

In this embodiment, an air cap 18 as shown in FIG. 6 is attached so as to make a predetermined angle in the direction in which the atomized droplets are ejected.
A nozzle 17 is attached to the front end of the mixing portion 15 with a nozzle nut 16, and the rear end portion of the air cap 18 is pressed against the stepped portion 16 a of the nozzle nut 16, and the air cap 18 is applied to the front end inner protrusion 11 b of the extension pipe 11. In this example, the rear end of the extension pipe 11 is screwed to the joint member 20 so as to tighten the rear end outer stepped portion 18c.
Although there is no limitation in the connection method of the nozzle nut 16 and the mixing part 15, the thread part 15m was formed in the front end side of the mixing part 15, and the internal thread part 16b was formed in the rear part of the nozzle nut 16 in the present Example.

As shown in FIG. 5, the nozzle 17 has a spray wire feed hole (insertion hole) 17 d at the center, and a plurality of mixed gas ejection holes 17 b are arranged concentrically.
The ejection holes 17b are formed obliquely so as to narrow down in a conical shape from the rear end side toward the front end side.
In this embodiment, eight ejection holes 17b are formed concentrically, and the rear end of the ejection holes 17b faces a ring-shaped groove 15h formed at the front end of the first disk plate 15a.
Moreover, a part of air is sent into the insertion hole 17d of a wire (spraying wire) through the air supply path 17c.
Thereby, the wire is held at the center of the insertion hole 17d, and abnormal overheating of the wire is prevented.
Moreover, you may attach the inner conical guide piece 17 which guides a wire to the center side.

  The air cap 18 will be described with reference to FIG. 6 as shown in FIG. 6. The air outlet 18 a opened slightly diagonally downward, and the ejection direction of the nozzle 17 in order to give a predetermined angle to the spray direction of the droplets The cross air flow path 18b which ejects air in the direction which cross | intersects is formed.

Next, the flow of compressed air, oxygen gas, and fuel gas in the extension 10 will be described.
The compressed air connected to the gun body 1 passes through the inside of the extension pipe 11 from the air inlet port 19d of the extension 11, and a part of the compressed air passes through the passage hole 18d of the air cap 18 as shown by the solid line arrow in FIG. Via, it spouts from the clearance S between the nozzle 17 and the air cap 18 to the tip of the tip of the nozzle 17, and a part flows through the air supply path 17c to the spraying wire insertion port 17d.
A part of the air is ejected in a substantially orthogonal direction via a cross air passage 18b having a substantially L-shaped cross section provided in the air cap 18.
The fuel gas is fed from the fuel inlet 19b shown in FIG. 1, the oxygen gas is fed from the oxygen inlet 19a, and is mixed by the mixing section 15 provided on the distal end side of the extension pipe 11, and the dotted arrow in FIG. As shown in Fig. 4, the nozzle 17 is ejected from the tip to form a combustion frame.
As a result, for example, as shown in FIG. 8, the droplets are sprayed at a predetermined angle, and can be sprayed uniformly around the nut 32.

DESCRIPTION OF SYMBOLS 1 Gun body 10 Extension 11 Extension pipe 12 Wire pipe 13 Oxygen conduit 14 Fuel conduit 15 Mixing part 16 Nozzle nut 17 Nozzle 18 Air cap 19 Connecting part 19a Oxygen inlet 19b Fuel inlet 19c Wire insertion port 19d Air inlet 20 Joint Element

Claims (4)

The flame spray gun extension
Inside the extension pipe with the air conduit function,
A wire pipe, oxygen conduit, and fuel conduit for feeding the thermal spray wire are arranged,
An extension for a flame spray gun, comprising a mixing portion of oxygen and fuel at a tip end side of the extension pipe and an injection nozzle for a mixed gas at the tip of the mixing portion.   2. The flame spray gun extension according to claim 1, further comprising an air cap for injecting air in a direction intersecting the thermal spraying frame for determining a direction of the thermal spraying frame at a distal end portion of the extension pipe.   3. The flame spray gun extension according to claim 1, wherein the mixing portion of oxygen and fuel forms a fuel gas suction port with respect to a disk-like member having an oxygen flow channel.   A flame spray gun using the extension according to claim 1.

Images