JPH10314626A - Arc thermal spraying machine of wire type - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obviate the adhesion and deposition of the droplets splashing from an arc point at and on the peripheral surface of a guide of an arc thermal spraying machine which forms a wedge-shaped arc chamber with a pair of jet air and melting a pair of wires by arc heat in the arc chamber. SOLUTION: The block center of a nozzle 32 is provided with a groove 33 for the guide 23 longitudinally long. Both side edges of this groove 33 are provided with nozzle ports 35 for ejecting the jet air 34 and the wedge-shaped arc chamber 37 is formed by a pair of the jet air 34. A pair of the wires W are fed and guided to the arc point P in the arc chamber 37 by the guide 23. The center at the bottom of the groove 33 is provided with the air nozzle 39 for ejecting the cleaning air. Compressed air is ejected to the peripheral surface of the guide 23 from the air nozzle 39 to splash the droplets tending to adhere thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire type arc spraying machine.

[0002]

2. Description of the Related Art The inventor of the present invention has previously proposed an arc spraying machine having a feature in a supply form of jet air for atomizing (Japanese Patent Laid-Open Nos. Hei 4-27461 and Hei 4-162260). etc). There, a pair of guides arranged in a V-shape are used to feed and guide the molten wire toward the arc point, and the molten wire is melted by arc heat. In order to atomize the molten sprayed metal and spray it toward the base metal, jet air for atomizing is jetted from a nozzle. The jet air is ejected and supplied in a V-shape along the left and right side surfaces of the pair of welding wires, and the ejection center axis of the jet air is directed so as to converge at the spraying center axis forward of the arc point, thereby forming a wedge-shaped arc. Form a chamber.

[0003]

In a wire-type arc spraying machine, in order to maintain a stable arc state, the tips of a pair of guides are brought as close as possible to an arc point.
The projecting length of the molten wire from the tip of the guide to the arc point is reduced to prevent the molten wire from wobbling. In such an arc spraying machine, a part of the droplet melted by the arc heat is scattered to the guide side and easily adheres to and accumulates on the peripheral surface of the guide. If the droplets are left untreated, the guides are short-circuited and the arc is interrupted. Therefore, every time droplet droplets grow, it is necessary to interrupt the thermal spraying operation and remove the droplet residues, thereby reducing the work efficiency. In many cases, the droplets grow on the upper half peripheral surface of the lower guide. However, depending on the spraying posture of the thermal spraying machine, the droplets grow on one of the left and right side surfaces, and may disturb the flow of jet air.

[0004] The droplets cover the outer surface of the guide and hinder heat dissipation. In addition, due to its own heat storage function, the residue of the guide may be overheated. In the superheated portion of the guide, the molten wire powder attached to the surface of the molten wire or the guide hole may melt and adhere to the guide hole, which may hinder the smooth passage of the molten wire. The molten wire coming out of the guide may cause fluctuation, and in any case, the arc state is likely to be unstable.

SUMMARY OF THE INVENTION It is an object of the present invention to allow droplets scattered from an arc point to a guide side to be blown off by using compressed air supplied to a nozzle, whereby droplet scum is deposited on the surface of the guide. It is an object of the present invention to provide a wire-spray type arc spraying machine which can eliminate an arc interruption or overheat of a guide due to accumulation of droplets, and can perform a spraying operation efficiently and in a stable state. Another object of the present invention is
A cleaning air nozzle is provided on the nozzle that jets the jet air for atomizing.The compressed air jetted from the air nozzle blows the droplets away, and the droplets adhere to and accumulate on the surface of the guide. It is an object of the present invention to provide a wire-spray type arc spraying machine which can prevent the occurrence of the problem.

[0006]

An arc spraying machine according to the present invention has a nozzle 32 for ejecting atomizing jet air on a front surface of a case 1 to form a wedge-shaped arc chamber 37, and a nozzle 32 provided on the nozzle 32. The molten wire W, which is forcibly fed through the groove 33,
There is provided a pair of upper and lower guides 23 for feeding and guiding toward the arc point P in the nozzle 7, and blows the droplets scattered from the arc point P toward the guide 23 on the inner surface of the groove 33 of the nozzle 32. Air nozzle 39 for cleaning
Is provided. Specifically, an opening 42 of the air nozzle 39 for cleaning is opened near one of the front ends of the upper and lower surfaces of the inner surface of the groove 33, and the cleaning air blown out from the opening 42 is supplied to the other front. A guide surface 40 for guiding the deflection toward the front of the nozzle is formed. If necessary, a plurality of injection holes 42 can be opened in the inner surface of the groove 33.

[0007]

An air nozzle 39 for cleaning is provided on the inner surface of the groove 33 of the nozzle 32, and compressed air is blown out from the air nozzle 39 to blow off the droplets, so that the droplets adhere to the peripheral surface of the guide 23 and deposit. Can be eliminated. According to the nozzle 32 in which the injection port 42 is opened on one of the upper and lower surfaces of the inner surface of the groove 33 and the guide surface 40 is formed on the other side, the cleaning air jetted from the injection port 42 is reversed at the opposing groove surface wall and the arc chamber is turned. 37 can be prevented from flowing. That is, it is possible to prevent the flow of the jet air 34 and the atomization of the droplets from fluctuating due to the cleaning air inverted on the groove wall. With the nozzle 32 having the plurality of injection ports 42 opened, the jetting position and the jetting direction of the cleaning air can be optimized, and the droplet residue can be effectively eliminated.

[0008]

【Example】

(Embodiment 1) FIGS. 1 to 5 show Embodiment 1 of an arc spraying machine according to the present invention. In FIG. 2, the arc spraying machine performs arc spraying using a pair of upper and lower molten wires W in a round shape. The molten wire W is introduced into the rectangular box-shaped case 1, and is forcibly sent out to the front of the case by a feed mechanism in the case 1.

In FIG. 3, a case 1 has an aluminum case body 2 having one side opening, insulating blocks 3 and 4 fixed to the front and rear of the case body 2, a lid 5 for swinging the opening and closing, and a front side. And a bracket 6 covering the front surface of the insulating block 3. One end of the lid 5 is supported by a hinge 7 at one end, and a latch piece 8 provided on the outer surface of the other end is latched and fixed by a lever-link type latch 9 to maintain a closed state. The bracket 6 can be removed from the insulating block 3 by loosening a pair of upper and lower screws 10.

The feed mechanism is provided between the front and rear insulating blocks 3 and 4, and is fixed to the roller shaft 13 supported by the upper and lower walls of the case body 2 via bearings 12 as shown in FIG. It comprises a pair of upper and lower drive rollers 14, a pair of upper and lower press rollers 15 (see FIG. 3) for pressing the molten wire W against the drive roller 14, a geared motor 16 for driving the roller shaft 13 to rotate, and the like. The holding roller 15 is supported by a spring arm 17 attached to the inner surface of the lid 5 via a shaft 18 so as to be freely rotatable. The spring arm 17 is
To open the cover 5 at the same time. The motor 16 is housed in a grip 19 and can be started by turning on a toggle switch provided on the rear insulating block 4.

In order to guide the molten wire W, a pair of upper and lower guide tubes 22 are fixed to the insulating block 4 on the rear side.
Further, in order to guide the molten wire W sent from the drive roller 14 toward the arc point P, the upper and lower pairs of the guide 23 and the deflection guide tube 24 are formed in a V-shape before and after the front insulation block 3. Provided. The guide 23 and the deflecting guide tube 24 are respectively screwed and mounted on the power supply terminals 25 embedded in the insulating block 3. While the molten wire W passes through the deflection guide tube 24 and the guide 23, it contacts the inner wall surface and an arc current is applied.

In FIG. 1, a guide 23 is provided with a power supply terminal 25.
And an arc point P from the mounting portion 26.
A turning part made of a stainless steel, a copper alloy, or the like integrally formed with a shaft part 27 protruding toward the center, and a guide hole 28 for transferring and guiding the molten wire W is vertically penetrated along the center axis thereof. I do. More specifically, the screw shaft 29 and the fastening portion 30 having a hexagonal cross section for screwing operation form an attachment portion 26, and the screw shaft 29 is screwed and fixed to the power supply terminal 25. In order to obtain a stable arc state, the diameter of the entire shaft portion 27 is reduced, and the tip of the shaft portion 27 is arranged as close as possible to the arc point P, thereby preventing the molten wire W from wobbling.

On the front face of the bracket 6, there is provided a nozzle 32 for blowing out compressed air for atomizing. Nozzle 32
Is formed in a vertically elongated rectangular parallelepiped shape, and as shown in FIG. 1 and FIG. A pair of nozzle ports 35 for ejecting a flat jet air 34
Is opened like a slit. The compressed air is supplied to the nozzle 32
Is introduced into the nozzle via a hose joint 36 provided on the lower end surface of the nozzle.

As shown in FIG. 4, the nozzle port 35 is opened at a symmetrical position with respect to the spraying center axis H, so that the jetting center axes R of the two jet airs 34 are on the spraying center axis H ahead of the arc point P. Are oriented to intersect. This allows
The two jet airs 34 converge at a forward position away from the arc point P to form a gathered airflow, and form a wedge-shaped arc chamber 37 before they gather. The protruding end of the guide 23 is located in the arc chamber 37, and the arc point P is located on the front side of the converging portion of the jet air 34.

Most of the droplets melted at the arc point P are attracted by the jet air 34 and taken into the airflow, but a very small portion of the droplets scatter to the guide 23 side to adhere to the guide peripheral surface. I do. A cleaning air nozzle 39 is provided on the inner surface of the groove 33 of the nozzle 32 in order to prevent the deposition and deposition of the droplet residue. Specifically, as shown in FIGS. 1 and 5, an air nozzle 39 is provided at the center of the bottom wall of the groove 33.
A guide surface 40 is provided at the center of the upper wall of the groove 33 to guide the cleaning air blown out from the air nozzle 39 to the front of the nozzle 32. Air nozzle 39
Is formed vertically so as to communicate with the air chamber 41 on the lower inner surface of the nozzle 32, and makes the injection port 42 opening at the center of the bottom wall of the groove 33 face the shaft 27 of the lower guide 23.

As described above, according to the nozzle 32 provided with the air nozzle 39 at the bottom of the groove 33, the jet air 3
Compressed air of approximately the same pressure (6 kg / cm ² ) as
And the peripheral surface of the shaft portion 27 of the guide 23 can be constantly cleaned by the jet airflow.
3 can be prevented from adhering and accumulating on the shaft 27. After the jet air flow wraps around the upper and lower guides 23, it is deflected by the guide surface 40 and is discharged above the front surface of the nozzle 32, so that the jet air flow fluctuates the flow of the jet air 34 and the atomization state of the droplets. Can be prevented. The jet airflow also serves to forcibly cool the shaft portions 27 of the upper and lower guides 23, and can prevent the shaft portion 27 having a reduced diameter from being overheated.

(Embodiment 2) FIG. 6 shows an embodiment in which the air nozzle 39 is changed. There, the air nozzle 39 is formed as an independent part separate from the nozzle 32 and its screw portion 44 is formed.
Was screwed into the bottom of the groove 33 to be integrated with the nozzle 32. The passage in the air nozzle 39 communicates with the air chamber 41 via a passage 45 provided in the nozzle 32. As described above, when the air nozzle 39 is formed as an independent component, the air nozzle 39 is independent of the structure and shape of the nozzle 32.
Can be freely changed, and the blowing direction and the amount of blowing air can be adjusted and changed. An air nozzle 39 may be attached to each of the bottom and the upper wall of the groove 33 to individually clean the upper and lower guides 23. When the jet airflow is jetted toward the arc chamber 37, the flow of the jet air 34 is disturbed. Therefore, the jet direction of the airflow is set so as to avoid the jet air 34 outflow region.

(Embodiment 3) FIG. 7 shows an embodiment in which the arrangement structure of the air nozzle 39 is changed. There, a pair of air nozzles 39 is provided on the left and right sides of the bottom of the groove 33 so that the guide 2
The cleaning air can be blown out along the left and right peripheral side surfaces of No. 3. By providing a plurality of nozzles 42 in this way, the jetting position and the jetting direction of the airflow jetted from each nozzle 42 can be optimized, and droplet dross can be effectively eliminated.

In addition to the above embodiment, the injection port 42 is
Can be formed in a slit shape. The nozzle 32 can be formed in a U-shaped block in which the upper end of the groove 33 is open when viewed from the front. In this case, the guide surface 40 can be omitted. Instead of the guide surface 40, the jet airflow may be deflected and guided by a plate-shaped deflector. The air nozzles 39 for cleaning can be provided on the left and right inner side surfaces of the groove 33, and may be provided on the front side of the nozzle 32 if necessary.

[0020]

According to the present invention, a cleaning air nozzle 39 is provided on the inner surface of the groove 33 of the nozzle 32, and the air flow blown out from the air nozzle 39 is blown onto the peripheral surface of the guide 23, so that the melt scattered from the arc point P is blown. Guide 2
3 was prevented from adhering to the peripheral surface. Accordingly, it is possible to prevent the deposition of the droplets on the guide surface and to prevent the arc from being interrupted, and it is also possible to eliminate the operation of removing the deposited droplets. Further, it is possible to prevent the guide 23 from overheating due to the deposited droplets and the wire powder from sticking to the guide holes,
As a whole, the spraying operation can be performed efficiently and in a stable state for a long time.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view of a main part of an arc spraying machine.

FIG. 2 is a side view of the arc spraying machine.

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is a cross-sectional plan view of a nozzle.

FIG. 5 is a front view of a nozzle.

FIG. 6 is a vertical sectional side view of a main part of an air nozzle according to a second embodiment.

FIG. 7 is a vertical sectional front view of a main part of an air nozzle according to a third embodiment.

[Explanation of symbols]

1 ... case, 23 ... guide, 32 ... nozzle, 33 ... groove, 34 ... jet air, 37 ...
… Arc chamber, 39… Air nozzle, 40
……… Guide surface, 42 …… Nozzle, W ……….
…… Arc point

Claims (3)

[Claims] 1. A nozzle 32 for forming a wedge-shaped arc chamber 37 by jetting jetting air 34 for atomizing on the front surface of a case 1 and a groove 33 provided in the nozzle 32 penetrating back and forth to forcefully. There is provided a pair of upper and lower guides 23 for feeding and guiding the fed molten wire W toward the arc point P in the arc chamber 37.
3. A wire-type arc spraying machine comprising a cleaning air nozzle 39 for blowing off droplets scattered toward the side 3. 2. An injection port 42 of an air nozzle 39 for cleaning is opened near one of the front ends of the upper and lower surfaces of the inner surface of the groove 33, and the cleaning air jetted from the injection port 42 is supplied to the other front part. 2. The wire-spray type arc spraying machine according to claim 1, wherein a guide surface 40 for guiding the deflection toward the front of the nozzle is formed. 3. The wire spraying type arc spraying machine according to claim 1, wherein the plurality of injection holes are opened in the inner surface of the groove.