JP4394484B2 - Arc spraying equipment - Google Patents

Description

  The present invention relates to an improved arc spraying apparatus for performing thermal spraying effective for rust prevention and corrosion prevention treatment of electrical equipment, large steel structures and the like.

In arc spraying, two sprayed wires (hereinafter referred to as both sprayed wires) are respectively fed to the contact tip of the spray gun, an arc is generated between the tips of both sprayed wires, and sprayed by arc heat. This is a thermal spraying method in which a wire is melted, the molten metal is refined by spraying with a compressed gas or the like while the sprayed wire is fed in accordance with the melting rate, and sprayed onto the object to be sprayed to form a sprayed coating.

FIG. 2 is a diagram showing a configuration of a conventional arc spraying apparatus. In the figure, the thermal spraying power source apparatus 1 is supplied with electric power to the thermal spray gun 2 with the output of the commercial power source being subjected to constant voltage control, for example, by an inverter control circuit. The compressed gas ejected from the compressor 3 passes through an electromagnetic valve (not shown) provided in the thermal spray power supply device 1 and is ejected to the thermal spray gun 2. Two wire rod supply devices (hereinafter referred to as both wire rod supply devices) 4a and 4b are respectively provided with push feed portions through which both thermal spray wires from the wire rod reels 5a and 5b are fed, and guide tubes 8a and 8b. As a result, the guides for feeding both the sprayed wires are performed between the both wire feeders 4a and 4b and the spray gun 2. The thermal spray gun 2 is provided with a pull feeding unit that relays both thermal spray wires and feeds them to the thermal spray. The spray gun 2 is provided with an anode and a cathode contact tip (not shown), and both spray wires are supplied to the spray gun 2 and energized. The spray voltage and the spray wire feed speed are set by the remote controller 6.

The operation will be described below.
When the operator presses the start switch 7 provided on the spray gun 2 to turn it on, the compressed gas passes from the compressor 3 through a solenoid valve (not shown) provided in the spray power supply 1. 2 is ejected. Further, both sprayed wire rods are fed from both wire rod supply devices 4 a and 4 b, guided by the guide tubes 8 a and 8 b, and fed to the spray gun 2. Further, electric power is supplied from the thermal spraying power supply device 1 to both thermal spray wires, and both the thermal spray wires are short-circuited at an arc generation position in front of the thermal spray gun 2, whereby an arc is generated at the intersection of the thermal spray wires.
Since the tips of the two sprayed wires are sequentially melted by the arc heat, the arc can be maintained by selecting an appropriate spray voltage and spray wire feed speed from the remote controller 6. At this time, when the compressed gas supplied from the compressor 3 is blown to the arc at the intersection of the two sprayed wires, the molten metal is sprayed forward as a droplet and deposited on the sprayed material to form a sprayed layer. Is done.

  And when the thermal spraying is finished, when the operator opens the start switch 7 and puts it in the OFF state, the ejection of the compressed gas is stopped, the supply of both thermal spray wires and the energization of the thermal spray current are stopped, Thermal spraying is finished.

In the above-described push-pull type arc spraying apparatus, if the feeding speed of the push feeding unit and the pull feeding unit can be synchronized, the tension and compressive force applied to the thermal spray wire in the guide tube are reduced, Even when the guide tube is long, the sprayed wire can be fed stably.
However, the guide tube may be bent depending on the posture of the operator who is spraying. When the guide tube bends, a slight difference occurs in the feed speed between the push feed section and the pull feed section due to the gap between the guide tube inner diameter and the spray wire, so that the spray wire can be fed stably. Can not be.

Therefore, in order to stably feed the sprayed wire, the feed rate of the sprayed wire by the push feed unit is detected, the signal is fed back to the pull feed unit, and the push feed unit sends the sprayed wire. There has been proposed an arc spraying apparatus that is tuned so that the pull feeding portion is pulled by an extruded length.
Further, there has been proposed an arc spraying apparatus in which the push feeding unit feeds the sprayed wire with a constant torque and the pull feeding unit controls the speed of the sprayed wire. (For example, refer to Patent Document 1.)
JP 2001-262310 A

The feed force of the push feed unit and the pull feed unit needs to be greater than the feed force that cancels the feed resistance acting on the sprayed wire in the guide tube. Therefore, for example, in a working environment where a guide tube having a length exceeding about 10 m is required, a push feeding unit and a pull feeding unit having a large feeding force are necessary, and the arc spraying apparatus is increased in size. In this case, since the operator manually operates the thermal spray gun and moves the wire supply device frequently in the field work, it is not possible to perform efficient work.
As a result, the length of the guide tube is limited by the feeding force of the push feeding unit and the pull feeding unit. In addition, when the guide tube is bent depending on the working posture, the feeding resistance acting on the sprayed wire increases, so that the length of the guide tube is further limited.
Therefore, in the conventional arc spraying apparatus described above, for example, when a guide tube having a length exceeding about 10 m is required, the sprayed wire cannot always be fed at a constant speed, and a uniform sprayed coating is formed. Could not be formed.

  An object of the present invention is to provide an arc spraying apparatus that can always supply a sprayed wire at a constant speed and, as a result, can form a uniform sprayed coating.

In order to achieve the above object, the first invention provides:
Pull to feed two target wires and two wire feed device with a push feeder for feeding each, it relays the two target wires fed from each of the two wire feeder to the spray material a spray gun for performing arc spray has a feeder, and two guide tubes which performs the two and the wire feeder the spray gun and the two target wires of feed guides between each In the arc spraying equipment provided,
The two guide tubes have a normal inner diameter at a predetermined length from each connection side to the two wire supply devices, and an inner diameter that is larger than usual from there to the connection side to the spray gun. An arc spraying apparatus characterized by that.

  The arc spraying apparatus of the present invention is stable by setting the guide tube to have a normal inner diameter at a predetermined length from the connection side to the wire rod supply apparatus, and from the connection side to the spray gun to a larger inner diameter than usual. The sprayed wire can be fed, and as a result, the arc can be stabilized, and a uniform sprayed coating without the unevenness of the sprayed coating can be formed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on examples with reference to the drawings.
FIG. 1 is a cross-sectional view of a guide tube in which guides for feeding both sprayed wires are performed between a wire supply device and a spray gun in an arc spraying device of the present invention. In the figure, guide tubes 9a and 9b are used in place of the prior art guide tubes 8a and 8b shown in FIG. 2, and are made of a material that is flexible and does not expand and contract in the axial and radial directions. Yes. The inner diameter D1 of the push side tubes 91a, 91b from the connection side to the both wire supply devices 4a, 4b shown in FIG. 2 to a predetermined length is the normal inner diameter with a small difference between the outer diameter of the sprayed wire and the inner diameter of the guide tube. It is said. Further, the inner diameter D2 of the pull side tubes 92a, 92b from the tip of the push side tubes 91a, 91b to the connection side to the thermal spray gun 2 is set to be larger than the inner diameter D1 of the push side tubes 91a, 91b. The other functions are the same as the functions shown in FIG.

  In FIG. 1, for example, when the guide tubes 9a and 9b are bent, if the difference between the outer diameter of the thermal spray wire and the inner diameter of the guide tube is large, the frictional resistance acting on the thermal spray wire in the guide tube greatly changes. The sprayed wire cannot be delivered stably. Therefore, in order to reduce the change in the frictional resistance, the inner diameter D1 of the push side tubes 91a and 91b is set to a normal inner diameter with a small difference between the outer diameter of the sprayed wire and the inner diameter of the guide tube.

When a long guide tube is used, if a guide tube having a normal inner diameter with a small difference between the outer diameter of the thermal spray wire and the inner diameter of the guide tube is used over the entire length, the above-mentioned ratio is proportional to the length of the guide tube. The frictional resistance increases and the sprayed wire cannot be fed stably.
Therefore, the inner diameter D1 of the push side tubes 91a and 91b is set to a normal inner diameter, and the inner diameter D2 of the pull side tubes 92a and 92b is set to an inner diameter larger than the inner diameter D1 of the push side tubes 91a and 91b. Even so, the frictional resistance is not increased.

  The lengths L1 and L2 and the inner diameters D1 and D2 of the push side tubes 91a and 91b and the pull side tubes 92a and 92b described above are the outer diameter and tensile force of the sprayed wire, and the frictional resistance acting on the sprayed wire in the guide tubes 9a and 9b. These are determined in advance from the respective feeding forces of the push feeding unit and the pull feeding unit, the operability of the spray gun 2, and the like.

The operation will be described below.
The two thermal spray wires are pulled out from both the wire reels 5a and 5b by the push feed portions provided in the both wire feeders 4a and 4b shown in FIG. 2, and are guided to the guide tubes 9a and 9b shown in FIG. Are fed to the spray gun 2 respectively. Both thermal spray wires are stably fed with little change in frictional resistance by being guided by push side tubes 91a and 91b formed with a normal inner diameter. Then, by being guided by the pull side tubes 92a and 92b formed with an inner diameter larger than the inner diameter D1 of the push side tubes 91a and 91b, the frictional resistance does not increase, and the feed is stably performed. Other operations are the same as those of the prior art shown in FIG.

  According to the experiments by the inventors, for example, in the case of performing arc spraying by feeding a zinc wire having an outer diameter of 1.3 mm using the guide tubes 9a and 9b having a length of 12 m, the push side tube 91a is used. 91b has an inner diameter D1 of 2 mm and a length L1 of 8 m, and the pull-side tubes 92a and 92b have an inner diameter D2 of 4 mm and a length L2 of 4 m. As a result, the sprayed wire was always fed at a constant speed to stabilize the arc, and a uniform sprayed coating having no irregularities on the sprayed coating could be formed.

  Further, for example, when the guide tube 9a or 9b having a length of 15 m is used to feed a zinc wire having an outer diameter of 1.3 mm to perform arc spraying, the inner diameter D1 of the push side tubes 91a and 91b is set to 2 mm. The length L1 was 10 m, the inner diameter D2 of the pull side tubes 92a and 92b was 4 mm, and the length L2 was 5 m. As a result, the sprayed wire could always be fed at a constant speed, and a uniform sprayed coating could be formed.

The guide tubes 9a and 9b used in the above-described arc spraying apparatus of the present invention connect two tubes having different inner diameters, but the two tubes need not be integrated and can be separated. Depending on the thermal spraying conditions, it may be possible to replace them.
Further, the number of guide tubes is not limited to two, and a plurality of tubes having different inner diameters may be connected according to the spraying conditions.

  Alternatively, the guide tube may be integrated, and the inner diameter thereof may be gradually increased from the connection side of the wire rod supply device to the connection side to the thermal spray gun to have a tapered shape.

It is sectional drawing of the guide tube in which the guide of feeding of both thermal spraying wires is performed between a wire supply device and a spray gun in the arc spraying device of the present invention. It is a figure which shows the structure of the arc spraying apparatus of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thermal spray power supply device 2 Thermal spray gun 3 Compressor 4a, 4b Both wire material supply apparatus 5a, 5b Wire material reel 6 Remote control 7 Start switch 8a, 8b Guide tube 9a, 9b (of this invention) Guide tube 91a, 91b Push Side tube 92a, 92b Pull side tube D1 Push side tube 91a, 91b inner diameter D2 Pull side tube 92a, 92b inner diameter L1 Push side tube 91a, 91b length L2 Pull side tube 92a, 92b length

Claims (1)

Pull to feed two target wires and two wire feed device with a push feeder for feeding each, it relays the two target wires fed from each of the two wire feeder to the spray material a spray gun for performing arc spray has a feeder, and two guide tubes which performs the two and the wire feeder the spray gun and the two target wires of feed guides between each In the arc spraying equipment provided,
The two guide tubes have a normal inner diameter at a predetermined length from each connection side to the two wire supply devices, and an inner diameter that is larger than usual from there to the connection side to the spray gun. An arc spraying apparatus characterized by that.

Images