KR810001970B1 - Metal melt spraying equipment - Google Patents

Abstract

None.

Description

Metal spraying device whose film does not cause shrinkage or deformation

1 is a longitudinal sectional view of the metal spraying machine of the present invention.

2 is an enlarged view of a main part of FIG.

3 is a front view of the thermal sprayer of FIG.

Figure 4 is a longitudinal sectional view of a semi-fixed electrode sprayer according to another embodiment of the present invention.

5 is a longitudinal cross-sectional view of a single molten iron spraying machine.

The present invention relates to the improvement of a new spraying machine which is different from the conventional spraying machine, and more particularly, to electrically melt the metal wire and simultaneously blow the volume of the molten metal into the jet stream and to coat or layer the metal on the surface of the workpiece. The present invention relates to a technique of metal spraying which is formed in a favorable state without causing shrinkage or deformation.

In the conventional thermal spraying machine, since the high pressure air passes directly through the place where the metal wire is melted, the volume of the molten metal is blown to the high temperature human body, which has an inevitable drawback.

The present inventors have developed a new spraying machine which is different from the conventional spraying machine and introduced it in US Patent No. 3,901,44.

According to the method of the patent, the defects in the conventional thermal spraying machine are basically eliminated, so that the metal film or layer can be obtained in an excellent state. This invention is different from the conventional thermal spraying technique, that is, the metal wire is melted at low voltage and low current. It is based on the groundbreaking technical concept of spraying molten metal volume by relatively low speed airflow, and it is possible to obtain a sprayed coating or layer with excellent quality.

However, there was a point that some improvement was necessary for commercialization of the thermal spraying device according to the method of the patent.

Therefore, to continue the research to complete the present invention to solve the problem for commercialization, the improvement achieved by the present invention is as follows.

i) In order to accurately resist the molten metal volume in the direction of the jet stream, a small amount of high pressure air is introduced into the low pressure zone in the small jet stream for the micropores, and the jet stream is directed to the melting place of the metal wire. The micropores are positioned close to the top of the cone to form an arc.

ii) In the case of forming the arc by injecting two metal wires to face each other, in order to solve the problem that the thermal spraying which is not suitable for arc formation is easy to be manufactured,

a) One electrode is made of poorly soluble metal and semi-fixed, and the other electrode is formed of a normal molten metal wire, arced to this anode, and sprayed in a two molten metal using a low voltage.

b) fine tuning the semi-fixed electrode.

iii) Use a single thermal sprayed metal wire and inject it through the center of the thermal sprayer to melt it in the column of heat by high frequency current.

IV) It is possible to control the injection airflow speed according to the specific object and use to obtain a good film or layer.

An object of the present invention is to provide a thermal spraying machine for performing metal spraying without cracking, shrinkage or deformation of the coating.

The basic technical concept of the present invention achieved for this purpose was introduced in US Patent No. 3,901,441 by the present inventor as described above. The method of this patent is different from the conventional spraying machine. .

That is, the air passage and the metal wire spraying position which are injected at high speed are separately provided, and the high speed air is blown out from the annular nozzle, and the injection angle is acute with respect to the axis. The metal wire melting apparatus is disposed inside the annular air, that is, inside the umbrella formed by the conical air stream.

Naturally, the inside of the umbrella is in a low pressure or vacuum state, and the action of the ejector causes the molten metal to be sucked into the jet stream and mixed with the jet stream. However, since high-density injection air does not pass through the molten metal in large quantities, there is no loss of heat or severe oxidation, and the metal melts at its own melting point with a small amount of power, and there is no need to melt it with an extra amount of heat. .

In addition, there are no drawbacks such as disturbance of arc action by high speed air, oxidation of metal, combustion and deterioration.

However, it should be emphasized here that the characteristics of such a new spraying machine are the biggest feature besides the above, that is, the properties of the sprayed coating are essentially different from the conventional ones. It is a point that a stable metal layer or a film can be obtained without this peeling.

That is, even when the thick metal layer which was previously impossible cannot be formed, peeling of the layer does not occur and deformation is not seen.

The reason why such a remarkable effect arises is drawn as follows.

That is, the molten metal first becomes a volume and then sucked into the jet stream.

The moment the particle enters the jet stream, the volume is first broken into pieces, the shape of which has a complex projection, for example a branch like a tree branch, and the minute particles are cooled by a strong and cold jet stream in a second, so the fine particles It is solidified in the shape of a tree branch and then shocked on the surface of the target.

At this time, it is considered that the projections are entangled with the projections of other fine particles around them, plastically deform, and solidify integrally to form a metal film.

In fact, recent research supports this.

By the way, even if the above-mentioned views on the new spraying machine are basically justifiable, there are also some unknowns in terms of actuality, and in order to obtain a good overall result, it is also denied that skill of operating such spraying machine is required. Since it was impossible to do so, the inventors of the present invention have invented the improved metal thermal spraying agent based on a more accurate technical basis as a result of repeated studies.

Before entering the detailed description of the present invention, the most characteristic features of the present invention are as follows.

1. Among the mechanisms for melting the metal wire itself or the mechanism for forming the ejector, the metal wire terminal melted by arc or contact heat or column heat in the low pressure or vacuum zone is sucked forward by the ejector action, but at this time melting Only the part that became liquid phase is separated from the tip.

At this time, the boundary between the liquid phase and the solid phase is not necessarily clear, but the liquid phase portion shaken by the wind pressure is blown away, and the remaining portion is in the state just before the liquid phase phase, and the release of ions is in full swing, which is perfect for the continuous generation of arc. This part immediately liquid-phases as a result of the application of, and a small arc heat or contact heat, the melting proceeds continuously and smoothly.

It has thus been found that the action of the spray can be improved by forming a small jet stream in order to reliably spray the volume of the molten metal forward and acting it at the above molten position.

Therefore, as a means for forming the small jet stream, the inclined hole is provided on the wall surface of the conical tube, which is a passage of the high speed air stream, through which a portion of the high speed air stream is introduced into the low pressure region, and the small jet stream is directed to the metal wire melting position. To blow the volume forward.

2. The second feature of the present invention is that the speed of the injection air or the amount of injection air can be adjusted according to the molten metal wire and / or the melting speed.

The speed of the injection air can be arbitrarily selected within the range of Mach 1 for 200 m / sec or more, and the injection angle (indicated by θ in Fig. 1) is in the range of 20 ° to 50 °, preferably 28 ° to 35 °. Just do it.

Here, by using a thicker metal wire, a large amount of metal can be sprayed at a time. In this case, it should be noted that the amount of injector flow is relatively increased so that there is no shortage in crushing power, cooling power, and conveyance force of molten metal particles. .

The control of the injection air greatly affects the formation of the coating or layer of the metal spray. In order to obtain a high quality coating, proper crushing and cooling of the metal volume is essential.

In the present invention, the metal volume is crushed into fine particles by the injection air, wherein the fine particles are in the form of tree branched complex protrusions and are then cooled and solidified in an instant.

Here, the shape of the 'branch branch' particles is similar to the shape when the complex shape of water droplets generated by, for example, the trough of the wave is blown by a strong wind, as well as the beard-shaped metal crystals. It refers to the irregular shape.

Therefore, chemicals and the like which cannot break up the volume of the metal are unsuitable for the present invention.

In the present invention, the spraying air is applied immediately after the volume of the metal wire is formed and just before cooling, so that the spraying air can be broken down into fine particles having tree branch protrusions and cooled and solidified by applying a force appropriate to a specific material of the volume. As described above, the speed or the amount of air is appropriately selected in accordance with the material of the molten metal wire and / or the melting speed in the range of Mach 1 or more at 200 m / sec.

3. In the method in which arc is formed by energizing two metal wires and the metal wire itself is melted by the arc heat, sometimes the inflow of the two metal wires is not uniformly performed, or the formation of arc is smoothly due to deformation of the metal wire. In order to solve the trouble caused by the failure, one of the molten metal wires is semi-fixed, and the other is a new method of heating with a high frequency current.

In order to clarify the features and advantages of the device according to the present invention will be described in detail with reference to the accompanying drawings.

1 to 3 of the accompanying drawings show a metal spraying machine according to the present invention, where (1) is a spraying nozzle, which is placed on a disk 17 fixed to the distal end of a case 27 forming an outline of the body. Detachable to the attached dish-shaped support 10 and attached to the left and right rotation materials.

A conical tube 2 is built into the thermal spray nozzle 1 to divide the space inside the nozzle into and out, and a conical hole 41 is formed at the distal end of the thermal spray nozzle in the center of the disk. ), And as shown in the drawing, the conical tube 2 is inserted into the inside of the conical hole 41, and since both inclination angles are the same, a narrow annular passage 42 is formed between them. An end annular injection port 18 is formed. Separately, the high-pressure air delivery pipe 4 from the compressed air device (not shown) communicates with the nozzle in the side wall of the thermal spray nozzle 1, so that the space generated between the conical tube 2 and the thermal spray nozzle, that is, the high-pressure air It communicates with the thread 31.

Therefore, the high pressure air is injected out of the injection hole 18 through the annular passage 42 between the surface of the conical tube 2 and the inner wall surface of the conical hole 41. Reference numeral 15 denotes a base of the spray nozzle, and the base 15 is provided with a vent hole 6 for communicating the outside air with the inside of the conical tube 2.

On the other hand, a set of conduits 7a and 7b for guiding the molten metal wires 8a and 8b is inserted into a set of perforations 28a and 28b provided in the disk 17 to the bolts 11a and 11b. It is fixed so that it can pass through the inside of the conical tube 2, and as shown in the figure, it is comprised so that the front end part may reach | attain the outer surface 3 of the injector sphere 5 substantially in the state which approached each other.

Therefore, when the metal wires 8a and 8b pass through the conduits 7a and 7b and come out of the outside, they are brought in close proximity or contact with each other in reverse V-shape, and the conductive terminals 9a and 9b connected to the power supply are provided in the conduits. Are respectively connected. The melting position of the metal wire is slightly ahead of the injection port 5 and is later than the focal point 20 of the injection stream.

In the case 27 forming the body of the body, rollers 12a and 12b are provided with a metal wire inlet, and driving thereof is performed via the worm wheel 14 of the shaft 13 of the roller. . 16 is a worm.

In addition, the gas delivery pipe 29 is also provided in this part.

Now that the outline of the mechanism has been described, the passage of high pressure air will now be described. When the high pressure air is pumped from the high pressure air delivery pipe 4 into the aircraft, it is first introduced into the pneumatic air chamber 31 and then injected through the annular passage 42 to the outside from the injection port 18.

This jet stream 21 is conical and once gathered at the focal point 20, becomes a dissipation stream 21 '. The inner space 19 from the focal 20 becomes a strong low-pressure zone, and thus the metal wire melting position and The apparatus is excreted in this low pressure zone and the molten metallic area is drawn toward the focal point 20 of the high velocity jet. Therefore, unless molten metal is blown in the low pressure region 10, molten metal is not blown forward, but the supply of this air is achieved by blowing outside air from the air vent 6.

In the present invention, a small amount of high pressure air is sprayed by arranging the inclined hole 40 in the wall of the conical tube 2 forming the annular passage 21 of the high pressure air, and defining the direction to direct the metal wire melting part. The air flow is introduced into the low-pressure zone and the volume is pushed forward by the iso jet flow.

This is one of the features of the present invention, this inclined hole 40 is also called a third injection hole, the diameter is extremely small, that is, to facilitate smooth spraying by laying a plurality of about 0.5mm.

Depending on the type of metal wire, there is an extreme dislike for oxidation. In such a case, a method of injecting separately prepared inert gas from the gas injection port 24 (called the second injection hole) opening in the conical tube via the gas delivery pipe 29 and enveloping the metal wire with this gas may be taken. have. This method can achieve its purpose with an extremely small amount of gas.

Although the apparatus and main part of this invention were as above-mentioned, other metal wire transfer apparatus is provided in the back body part of a base | substrate, and the electrical terminal is also provided in this part.

On the other hand, the electric device, the air compressor, and the gas storage device as the accessory equipment can be freely designed and adopted according to the purpose.

Next, the operation and features of the thermal spraying method and thermal spraying machine according to the present invention will be described. As described above, the high pressure air for injecting molten metal passes through the annular passage 42 from the high pressure air chamber and is ejected from the injection port 18 to form a conical injector stream. It is generated by the arc 23 by the metal wires during the operation and does not generate the plasma phenomenon.

That is, it does not pass through the metal melting position.

In the conventional method, high-speed air flows directly through the arc part, thereby cooling the arc part, causing a plasma phenomenon due to the pinch effect, generating an extremely high temperature, and consuming excessive current that excessively melts the metal, thereby inducing loss of electricity and volume generation. There was a flaw.

However, there is no such drawback in the present invention.

That is, in the present invention, the high-pressure air does not pass through the metal melting position, but passes through a separate passage, and the metal volume is mixed with the jet stream by the ejector action. At this time, the volume is broken and cooled. In the conventional method in which air flow passes directly through the arc part, the air flow cools the arc part, generates a plasma phenomenon due to the pinching effect, generates an extremely high temperature, and consumes an excessive current that excessively melts the metal. There are no drawbacks to incapacity for production and a substantial improvement.

For example, in the conventional method, the power of 45V and 600A is required, but in the case of the present invention, the same effect can be obtained with a voltage of 17V or less and a current of 100A or less, and there is a large difference between them. In addition, when the effect of the third injection hole 40 is supplemented, the small jet stream directed to the low-pressure zone 19 is quite strong, and since it is directed in the volume direction, the volume is pushed in the direction of the focal point 20 to attract the suction force. It is to achieve a desirable effect of correcting the volume of star art advancing into. Therefore, the angle of inclination of the inclined hole has an important meaning. And since it is a minute airflow, it is also important to provide it in the position near arc.

If the position and angle of the small holes are not appropriate, the function of the apparatus will be significantly reduced if the injector stream 21 is disturbed without producing the above-described effects.

As described above, the thermal spraying value in the present invention separates the metal wire melting position and the passage of the high pressure air, respectively, and puts the molten position of the metal in the low air flow zone generated by the injector flow, so that the volume 33 moves in the injecting air flow direction. At the same time, the suctioned volume is crushed and quenched to form fine particles 34 with complex projections, which are shock-compressed onto the target object by injecting airflow, and the fine particles are adjacent to each other. The film is formed by plastic deformation, crushing, and integrally fixing in a state where the protrusions are entangled with each other, and the film formed therein is not a cooling agent during lamination as a lamination agent of cooled fine particles, so that no shrinkage or deformation of the film occurs.

According to the present invention, since the speed and the spray angle of the jet stream are optimally adjusted according to the type of metal, the amount of melt, etc., the crushed fine particles are plastically deformed in a state where adjacent ones are entangled with each other to form a metal film on the processed surface. Therefore, no shrinkage or deformation of the film occurs.

The injection angle of the high pressure air flow indicated by θ in FIG. 1 is generally in the range of 20 ° to 50 °, preferably in the range of 28 ° to 35 °, and the speed of the injection air flow is in the range of 200 m / sec to Mach 1 degree. You may select appropriately.

If the quench is inadvertently insufficient, or if you have made a rudimentary mistake, for example, by bringing the sprayer too close to the subject, there may be some drawbacks. The formation mechanism of the sprayed metal film is different from the direct injection method.

Therefore, no shrinkage or deformation occurs.

For this reason, the use surface of this invention is extremely extensive.

Next, the improved form by this invention is demonstrated.

In the above two molten iron system of FIG. 1, two metal wires are always melted to the same extent, and therefore, it is necessary to simultaneously lift the metal wires in equal amounts. Otherwise arcs cannot be sustained.

For this reason, the automatic feeding device is provided so that both wires are always inverted V-shaped, but sometimes the arc can not be obtained due to the deformation or deterioration of the metal wire. There were many aspects that required the experience and skill of the operator to control the amount of feeding.

What is shown in FIG. 4 improves this advantage.

That is, in order to further simplify the operation, the arc forming the arc is made of a poorly molten material such as tungsten and a semi-fixed electrode, and the other electrode is made of a common thermal spray metal wire 8, and the arc is formed by this anode. Using a low voltage, thermal spraying is carried out in the same manner as in the above two-melting type. That is, the metal wire feeding roller 12 is always operated with respect to the metal wire 8, but the metal wire 8 'side is not normally operated, but is configured to operate as needed.

This eliminates the arc defect caused by the failure of the two-barred type device, ie, the failure of the two metal wires to be exactly opposite due to the bending or vibration of the metal wire or the wear of the conduit.

As can be seen from the figure, the support 58 of the thick semi-fixed electrode 54 is attached to the inner wall of the thermal spray nozzle 1, and the thermal spray nozzle can be rotated so that the thermal spray nozzle can be rotated by hand. By rotating, fine adjustment can be made to arc formation.

If a normal metal wire is inserted instead of the fixed electrode 54 and the feed roller 12 'is operated, it becomes a two-line type, and one electrode is supported by an unadjustable support so that the arc can be adjusted during operation. It is easy to handle, improves efficiency and improves product quality. Since it is possible to adjust the arc at all times during the operation, a homogeneous coating is obtained, which is a significant improvement of the defects of the conventional apparatus.

Now, the structure of the semi-fixed electrode sprayer will be described with reference to FIG. The thermal spray nozzle 1 is inserted into the inside of the cylindrical case 57 'which is circumferentially attached to the base base 57 and is integrally attached.

In front of the spray nozzle 1, an injection hole 51 having a conical hole 41 is attached, and a base 52 'of an inner nozzle 52 which forms a hollow cone is fixed to an inner wall surface.

The distal end of the inner nozzle 52 is fitted into the conical hole 41 provided in the injection hole 51, and is configured to have a slight gap 42 between the two because the inclination angles are the same. The uppermost end of the annular passage forms the injection hole 18.

In addition, the inner wall of the inner nozzle 52 is attached to the support 58 of the electrode 54 made of a poorly soluble material, for example, tungsten or the like, or a rod, and a molten metal wire inside the inner nozzle 52. The conduit 7 of 8) is refracted and mounted as shown in the drawing, and the tip of the metal wire passing through this speed is configured to approach the fixed electrode in an inverted V shape to form an arc or to contact each other to generate heat.

In this manner, only the metal wire 8 is melted and sprayed. In other respects, the method of Fig. 1 is roughly the same as in Fig. 1, where 4 is a pipe for introducing high pressure air, and 55 is an air hole communicating with the low-pressure zone 19 and outside air, which is an inert gas chamber (not shown). May not be used).

Denoted at 31 is a high pressure air chamber, and 12 and 12 'are metal wire feeding rollers.

This device is called semi-fixed because one electrode is fixed to the support but can be rotated as a whole as described above, but it is to be noted that the formation of arc is easy since one side of the electrode is semi-fixed and not consumed. In addition, the fixed electrode itself is fixed to the thermal spray nozzle 1 so that the formation of the arc can be finely adjusted by rotating the thermal spray nozzle, so that the state of the arc can always be adjusted to the best state during the operation, thereby improving its efficiency. The quality of the film and the film is superior to that of the conventional apparatus.

Moreover, since the quantity of cold injector stream is large enough with respect to the quantity of heat which the volume which arises in one metal wire has, the cooling effect is much more excellent than the two molten iron type | mold.

Therefore, it is especially effective for high melting point metals.

In addition, the operation | movement in which the high pressure air is injected from the injection port 18, the melted volume is sucked into this airflow, crushed and cooled simultaneously, and blown to the injection airflow is as described previously.

In the case of such a semi-fixed electrode, it is also possible to pass the molten metal wire through the fixed electrode support 58 and let it in by the roller 12 'and use it as a two-melt type.

Even in this case, since the arc can be unadjusted, it is extremely easy for the worker to use, and therefore, the effect of improving the efficiency and improving the quality of the film is enormous. The difference between the case where there is only one molten metal wire and the case where there are two molten metal wires is that the former has a small amount of metal to be thermally sprayed. The latter is suitable for any use.

In addition, it is generally practiced to generate both electrodes as arcs, but it is not necessary to necessarily generate heat as arcs, and the electrodes can be brought into contact with each other to melt the metal wires by the contact heat.

In this case, since melting proceeds without the temperature reaching unnecessary high temperatures above the melting point of the metal, there are fewer advantages such as less oxidation, combustion, and overheating of the metal, and also faster cooling, and the value of use thereof is high. In the conventional high temperature spraying method, this method cannot be adopted.

Next, another improved method, namely, a method of melting only one sprayed metal wire or rod with a high frequency current, will be described with reference to FIG. In Fig. 5, reference numeral 60 denotes an external nozzle and its overall shape is the side of the cup as shown in the figure, and the axial center portion of the side wall 72 corresponding to the bottom of the cup forms a projection 66. In addition, a conical hole 41 widened outward is installed in this part.

Inside the outer nozzle 60, the inner nozzle 61, which is an electromagnet, is incorporated. The inner nozzle 61 is also in the shape of a cup, the shaft wall 75 extending outwards to form a more steeply protruding portion 77 at the shaft center, and this portion is hollow so that the tip of the metal wire 63 is located. A chamber 76 is formed. The protrusion 77 fits inside the conical hole 41 of the shaft portion of the outer nozzle and forms a narrow gap 42 between the inner surface 74 of the cone hole and the outer surface 78 of the protrusion. This gap 42 serves as a passage for high pressure air.

The passage 42 is annular, the end of which forms an annular injection port 18. Therefore, when the high-pressure air of the compressed air device (not shown) prepared separately is introduced into the main body by the air pipe 64, the high-pressure air is discharged from the injection port 18 via the high-pressure chamber 31 and the passage 42. It is the same as that of the method already demonstrated that it sprays to the outside in abstract, becomes the injector stream 21 once gathered in the focal point 20, and is radiated and forms the injector stream 21 '.

An annular hard electric insulator 67 and a support body 68 are fitted into the inner nozzle 61, and the entire structure of the inner nozzle 61 constitutes a whole body of the thermal sprayer.

In addition, a high frequency electric coil 62 for melting the metal wire 63 by high frequency is wound around the outer circumference of the outer nozzle corresponding to the inner nozzle and the electromagnet as shown in the drawing. Next, the rear body 69 is joined to the rear of the whole body, thereby completing the spraying machine body.

An annular insulator 70 is inserted into the rear center portion of the rear body portion, and a high-pressure air transmission pipe 64 is provided through the front and rear body portions, and a thin vent hole communicating with the low-pressure zone 19 and the outside air. 65 is installed.

The molten metal wire 63 is penetrated by the rollers 12a and 12b so as to penetrate through the metal wire insertion hole 71 laid at the center of the gas, and the tip reaches the chamber 76.

As for the operation of the improved thermal sprayer, the injection mechanism of the high-pressure air is the same as described above, but since there is only one metal wire, and Joule heat by high frequency current is used to melt it, the pieces become extremely simple.

That is, the tip end portion of one metal wire 63 located at the center portion of the gas by passing the high frequency current through the coil 62 starts to melt from the display due to the Joule heat of the secondary high frequency current, and as soon as the volume becomes the jet stream Inhaled toward (21).

Since the tip of the metal wire continues to melt while receiving the heat of passage in the liquid phase, thermal spraying is continuously performed by continuously injecting the metal wire as much as the molten portion.

The action of forming the metal film on the surface of the subject by crushing, cooling, and blowing the volume is the same as that of the first two methods.

However, this apparatus is particularly superior in the simplicity of handling. This is because the single molten iron type requires no procedure for precisely adjusting two metal wires necessary for arc formation to a V-transformer as compared with the conventional two-wire type and semi-fixed electrode type, and thus the work is omitted.

In the two methods described above, there were occasions where skill was required. However, since this method uses only one metal wire, even beginners can easily and immediately achieve high quality without shrinkage or deformation in the film. It has a characteristic that metal spraying can be performed.

Claims (1)

A conical tube is built in the spray nozzle, and the spray nozzle is fitted to the end of the spray nozzle, and the small diameter portion of the conical tube is inserted into a conical round hole formed in the center of the spray nozzle. The high pressure air is passed through a round hole formed in the wall of the thermal spray nozzle, and the high pressure air passes through the gap and is blown out to the outside. The front part of the gas which communicates with the passage and the inside of the conical tube, and drills an inclined small hole whose direction is directed to the arc, and forms a ventilation hole at the base of the spray nozzle communicating with the outside and the inside of the conical tube. The front of the 2nd metal wire conduit bonded to the front part of the rear part which consists of a pore and a metal wire feeder, and penetrated through the sprayed gas in this way. Metal spraying apparatus directing a portion of the metal wire melting the crank hole and inclined inwardly enemy unit, and also the coating do not cause shrinkage or deformation, characterized in that it is formed at a position close to the metal wire melting portion.

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