JP2003505599A - Thermal spray equipment - Google Patents

Abstract

SUMMARY A thermal spray apparatus includes a thermal spray head forming a nozzle having a throat (132) through which pressurized gas can be supplied. First and second guiding means are provided to guide the raw material wire (124) at an angle of preferably 45 to 90 degrees with respect to the intersection in or near the end of the throat. The gas is energized through the throat at a high pressure, preferably at a pressure sufficient to generate a supersonic flow, whereby the molten raw material is finely atomized. The raw material guiding means may be a drilled tubular insert or an insert having a groove and supported by a cavity in the body member of the spraying head.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION

The present invention provides a thermal spray () for producing a corrosion-inhibiting and / or hard coating on a substrate.
The present invention relates to a thermal spraying device and a thermal spraying method.

[0002]

[Background technology]

International Patent Application No. WO98 / 00574 describes the above general thermal spraying method and thermal spraying apparatus.

[0003]

[Means for Solving the Problems]

It is an object of the present invention to provide a method and apparatus which is an evolution of the known thermal spraying method and apparatus.

The thermal spraying device provided by the present invention includes a throat having an intake port and an exhaust port, and a nozzle that is aligned with the shaft of the throat and forms a gas flow path capable of supplying a pressurized gas to the intake port. At least first and second guiding means configured to guide the raw material wire through the air inlet to an intersection in or near an end of the throat, and the throat connected to the raw material wire. A power source configured to generate an arc between the wires therein, and a pressurized gas supply means configured to supply gas to the throat, wherein the guiding means comprises the raw material wire. The raw material wire is configured to be guided to the intersection so that the angle is from 45 degrees to 90 degrees.

It is preferable that the guide means is configured such that an angle formed by the raw material wire is approximately 60 degrees. The nozzle may include first and second body members, each body member forming a portion of the throat. Generally, the throat is preferably inclined between the inlet and the outlet.

Each of the guiding means includes a hole formed in the main body member, and a part of the throat is formed by intersecting a part of each main body member, and each of the holes is formed with respect to an axis of the throat. It may be inclined. The guide means includes insert portions that can be supported in the respective holes, each insert portion has an opening through which a raw material wire can pass, and an inclined end surface having a shape that complements the shape of the throat. You may have.

Optionally, the respective holes intersect the locating cavities and the insert is supportable within the locating cavities for contacting a feed wire passing through the respective holes. Good. The insertion part may have a polygonal cross section and may form a plurality of flat surfaces having a positioning structure for contacting the raw material wire during use.

It is preferable that the insertion part has a square cross section and forms a plurality of rectangular flat surfaces having grooves formed in at least one surface for contacting the raw material wire during use. The insert may comprise copper or copper / tungsten. It is preferable that the main body member is electrically conductive and has a terminal or a contact portion that comes into contact with the power source by being in contact with each of the main body members. The body member is preferably provided on a non-conductive head that holds the body member in a separated state.

[0009]

DETAILED DESCRIPTION OF THE INVENTION

The thermal spraying apparatus illustrated in FIGS. 1 to 4 comprises a thermal spraying head which, in use, is connected to a supply of pressurized gas or nitrogen by means of a hose 10 and in use to a high power supply 12. The general principle of operation of this thermal spraying device is the above-mentioned International Patent Application No. WO98 / 00574.
(Meaning of International Publication No. WO98 / 00574)), it can be incorporated herein by referring to the contents thereof.

The thermal spray head of this thermal spray apparatus has first and second conductive body members 14 and 16, which are machined from an aluminum alloy and then molded, for example, from a suitable resin material such as PTFE. Alternatively, it is provided on the non-conductive head 18 which can be machined. As shown in the exploded view of FIG. 1, the body members 14 and 16 are hingedly coupled to the thermal spray head 18 using pins, which facilitates the assembly of the thermal spray head and the accurate positioning of the body members. The outer sleeve 56 made of a reinforced resin material such as nylon holds the main body member at a predetermined position and is operably arranged by the pin 58.

On the front surface of the thermal spraying head, there are a circular center portion 20 having an exhaust port 22 of a nozzle including an intake port 24 at its center, and a cylindrical throat 26 extending between the intake port and the exhaust port. is there. This throat is inclined from the intake port to the exhaust port so that the diameter on the intake port side is 8 mm and the diameter on the exhaust port side is 8.5 mm.

The cavities 28 and 30 are formed by machining the insides of the body members 14 and 16, respectively, and are inclined holes 32 and 34 (which intersect grooves 36 and 38 of the body member forming the throat 26, respectively. (Seems to be a typo of "two slanted holes 34" from FIG. 4). These inclined holes 32 and 34
(It seems that "these two inclined holes 34" are mistakenly written) forms an angle of about 30 degrees with respect to the axis XX of the throat, and the inclination angle formed by the two holes 34 is 60 degrees.

A copper insert 40 can be placed inside each hole, which end 4 has a shape complementary to the groove surfaces 36 and 38 forming the throat of the nozzle.
2, and when the insert 40 is in place in the hole 34, the end 42 is flush with the throat surface. A hole 44 is formed within each insert 40, the size of which supports the raw wire 46 and is capable of conducting with the other wire 46 as it passes through the insert and into the throat 26. It is supposed to be large.

In the prototype, the raw material wire 46 is guided to an intersection at the outer end of the throat 26 and substantially coincident with the exhaust port 22 and the central axis XX of the throat. In practice,
It has been found that this intersection is generally preferably within the throat, but in some applications it may be desirable to move the intersection outside the throat.

Electrical terminals 48 and 50 are provided on the body members 14 and 16, respectively, and are connected to heavy load conductors 52 and 54 that connect the body members 14 and 16 to the power source 12, and the body members 14 and 16 and the copper insertion portion. An electric current is passed through the raw material wire 46 via This causes an arc at the intersection of the raw material wires in the throat. In the prototype of the present invention, the power supply 12 was a constant voltage power supply operating at approximately 42-48 volts (compared to approximately 32-36 volts in conventional machines). The arc current was 150-300 amps and the gas pressure at the inlet was 2-5 bar (g), approximately 4 bar.

5 and 6 illustrate a second embodiment of the thermal spray head according to the present invention. Since most of the second embodiment is similar to the first embodiment, the main body member 14 of FIG.
Only the conductive main body member 114 corresponding to is illustrated. Body member 114 is joined to complementary body member 116 (see FIG. 6) and both body members 114 and 116 are
Is assembled to the non-conductive body member in the same manner as in the first embodiment.

The main difference between the first and second embodiments is that in the latter each body member forms a rectangular slot or cavity 118 for supporting a contact tip in the form of a removable insert 120. Is. As best shown in the cross-sectional view of FIG. 6, a hole 1 having a diameter larger than that of the feed wire 124 but relatively small.
22 extends from the upstanding head portion 126 of the body member 114, extends from the root of the head portion past the head portion 126, just above the bottom of the cavity 118, and further through the end portion 128 of the body member. The insert 120 has a machined central groove 134 on each of its four adjoining faces, the grooves circling the insert body at the shortest distance. Details of the function of the insertion unit 120 will be described later. As in the first embodiment, the positioning of the hole 122 and the central groove 134 of the insert 120 is such that the feed wire 124 is just midway or just above the end 130 of the throat 132 formed between the two body members. It is made to cross the point.

The throat 132 of the present embodiment has an inclined square or rectangular cross section rather than a conical hole because it is easy to machine and does not necessarily require a circular opening for the exhaust port. is there. Throat entrance is 6mm x 6mm, exit is 6
mm × 7 mm (rectangle).

The insert 120 has the same purpose as the copper insert 40 of the first embodiment and generally comprises copper or copper / tungsten. The through-hole 136 spreads from the side surface of the insertion portion 120 to the side surface, which facilitates the installation of the insertion portion 120. In the prototype, the insertion part has a length of about 20 mm in the direction of the through hole 136, and its surface has a size of 12 mm square.
The groove 134 had a depth of approximately 1 mm. As shown in FIGS. 5 and 6, dimples 138 are provided on both sides of the central groove on each surface and serve as a positioning member for fixing the locking ball or the grab screw 140.

As described above, when the raw material wire 124 is used, the insertion portion 120 has the raw material wire 1
It is located in the groove 134 with the biasing 24 guiding it to its intersection (see FIG. 6). Therefore, sufficiently good conduction is established between the raw material wire and the insertion portion.

The insert described above has many advantages over the tubular insert 40 of the first embodiment. First, because each insert has four wear surfaces, it only needs to be rotated 90 degrees to prepare a new surface. This means that the life of the insert is relatively long. It has been found that this insert does not fail as easily as if a drilled hole insert was used. This insert is easy to manufacture and can be easily fitted into the thermal spray gun head from the front side of the thermal spray gun head.

As described in the above-mentioned international patent application, by adjusting the pressure and amount of gas supplied to the inside of the nozzle, a flow of sonic gas or choke gas is generated inside the throat prior to the arc generation. It is preferred that the arcing in the throat acts in or just above the exhaust end of the nozzle to create a supersonic flow that is otherwise unattainable. The generated high-speed flow causes the molten raw material particles to be very finely sprayed and to move at a very high speed when the raw material particles are discharged from the nozzle to the substrate.

It has been found that the most effective results are obtained by using a sonic or supersonic gas flow to create an arc in the supersonic or sonic basin. Since the arc is very hot (approximately 4000 ° C.), the gas entering the arc rapidly heats and expands violently. This rapid expansion effectively acts as a gas supply means in the watershed, effectively blocking the flow of gas through the arc. This blocking effect causes the gas to try to flow around this "obstacle" in the same way that water flows around the concrete columns of the bridge.

In the presence of a supersonic gas flow, the gas flowing towards the “obstacle” (arc) is
The arc was "unaware" until it actually entered the arc zone, and thus the gas was forced into the arc zone. The resulting high pressure, high velocity flow causes the molten raw material to be atomized very finely. Thus, when the required amount of supersonic gas flow is used, the arc can be generated anywhere along the throat up to and slightly beyond the exit area of the throat. In the case of supersonic power spraying, the exhaust flow has a diamond-shaped supersonic flow region structure.

The raw wire 46 can be a conventional solid wire, but if a core wire having a tubular metal body containing cermet powder is used with nitrogen or another suitable noble gas,
It has been found to give excellent results. Cermet materials, generally agglomerated sinter mixtures of metals and carbides, because hard carbide materials are included in the metal binder,
It often improves the precipitation of carbide materials by this thermal spraying method. The use of pure nitrogen or other suitable noble gas prevents oxidation of the atomized metal source particles and significantly improves the quality of the coating product.

A relatively short injection distance between the nozzle outlet and the substrate to be coated (preferably less than 100 mm, preferably up to 5 mm) further suppresses the formation of oxides which are detrimental to the quality of the coating. I know that In prior art thermal spray equipment, a short jet distance may result in overheating of the substrate, but due to the very high velocity gas flow through the thermal spray apparatus of the present invention, gas jets prevent overheating and have a cooling effect.

At least 45 degrees, compared to the conventional crossing angle between the raw material wires, which is about 30 degrees,
By taking a relatively steep crossing angle of approximately 60 degrees, the end of the raw material wire at the arc generation point becomes more stable in the high-speed gas flow in the throat and the exposed cross section of the raw material wire becomes smaller. , The spraying of molten metal by the arc seems to be more uniform. In this regard, it is also important to design the wire guiding means so that it does not enter the throat and thus does not interfere with the gas flow in the throat.

[Brief description of drawings]

FIG. 1 is an exploded view of a first embodiment of a thermal spraying head of a thermal spraying device according to the present invention.

FIG. 2 is an external view of the thermal spraying device of FIG.

FIG. 3 is a rear view of the thermal spray device of FIG.

FIG. 4 is a sectional view taken along line 4-4 of FIG.

FIG. 5 is a partially exploded view of the second embodiment of the thermal spraying head of the thermal spraying device of the present invention.

FIG. 6 is a sectional view of a second embodiment of the thermal spray head according to the present invention.

[Explanation of symbols]

10 Gas Flow Hose 12 Power Supply 14, 16 Main Body Member 18 Thermal Spray Head 20 Circular Center Part 22 Exhaust Port 24 Intake Port 26 Throat 28, 30 Cavity 34 Hole 36, 38 Groove 40 Copper Insert 42 End of Copper Insert 44 hole 46 raw material wire 48, 50 electric terminal 52, 54 conducting wire 56 outer sleeve 58 pin 114, 116 body member 118 cavity 120 insertion portion 122 hole 124 raw material wire 126 upright head portion 128 body member end portion 130 throat end portion 132 Throat 134 Center groove 136 Through hole 138 Dimple 140 Grab screw

[Procedure for Amendment] Submission for translation of Article 34 Amendment of Patent Cooperation Treaty

[Submission date] August 11, 2001 (2001.08.11)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Contents of correction]

[Claims]

─────────────────────────────────────────────────── ─── Continued front page    (81) Designated countries EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, I T, LU, MC, NL, PT, SE), OA (BF, BJ , CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, K E, LS, MW, MZ, SD, SL, SZ, TZ, UG , ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AG, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, BZ, C A, CH, CN, CR, CU, CZ, DE, DK, DM , DZ, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, K E, KG, KP, KR, KZ, LC, LK, LR, LS , LT, LU, LV, MA, MD, MG, MK, MN, MW, MX, MZ, NO, NZ, PL, PT, RO, R U, SD, SE, SG, SI, SK, SL, TJ, TM , TR, TT, TZ, UA, UG, US, UZ, VN, YU, ZA, ZW

Claims (12)

[Claims] 1. A throat having an intake port and an exhaust port, a nozzle aligned with an axis of the throat to form a gas flow path capable of supplying a pressurized gas to the intake port, and the nozzle through the intake port. At least first and second guide means each configured to guide the feed wire to an intersection in or near the end of the throat, and an arc between the wires connected to the feed wire and between the wires. A power source configured to generate the gas, and a pressurized gas supply unit configured to supply gas to the throat, wherein the guide unit forms an angle of the raw material wire from 45 degrees to 90 degrees. So as to guide the raw material wire to the intersection point. 2. The thermal spraying apparatus according to claim 1, wherein the guide means is configured such that an angle formed by the raw material wire is approximately 60 degrees. 3. The thermal spray apparatus according to claim 1, wherein the nozzle has first and second main body members, and each main body member forms a part of the throat. And thermal spray equipment. 4. The thermal spraying apparatus according to claim 3, wherein each of said guide means includes a hole formed in said main body member, and a part of said main body member intersects to form a part of said throat. The thermal spraying device, wherein each of the holes is inclined with respect to the axis of the throat. 5. The thermal spraying apparatus according to claim 4, wherein the guide means includes therein insert portions that can be supported in the respective holes, and each of the insert portions has an opening through which a raw material wire can pass. And a thermal spraying device having an inclined end surface having a shape that complements the shape of the throat. 6. The thermal spraying apparatus according to claim 4, wherein each of the holes intersects with a positioning cavity, and the insertion part contacts the raw material wire passing through the holes. A thermal spraying device, which can be supported inside. 7. The thermal spraying apparatus according to claim 6, wherein the insertion portion has a polygonal cross section and forms a plurality of flat surfaces having a positioning structure for contacting the raw material wire during use. And thermal spray equipment. 8. The thermal spraying apparatus according to claim 7, wherein the insertion portion has a square cross section and a plurality of rectangles having grooves formed on at least one surface for contacting the raw material wire during use. A thermal spraying device characterized by forming a flat surface. 9. The thermal spraying device according to claim 5, wherein:
The thermal spraying device according to claim 1, wherein the insertion portion includes copper or copper / tungsten. 10. The thermal spraying apparatus according to claim 3, wherein the body members are preferably electrically conductive, and terminals or contact portions provided on the body members and contacting the power source are provided. A thermal spraying device characterized by having. 11. The thermal spray apparatus according to claim 10, wherein the main body member is provided on a non-conductive head that holds the main body member in a separated state. 12. A thermal spray apparatus according to claim 1, wherein the throat has a rectangular cross section.