JP5493485B2 - Thermal spray coating apparatus and power feeding method to wire - Google Patents

Description

  The present invention relates to a thermal spray coating forming apparatus for forming a thermal spray coating by injecting a molten thermal spray material toward an object to be sprayed, and a power feeding method to a wire, and more particularly to a power feeding technique to a wire.

  For example, a wire that becomes a thermal spray material is fed to the center of a revolving spray gun in accordance with the progress of thermal spraying, and the plasma generating part sprays plasma toward the wire to melt the wire and form a thermal sprayed metal There has been proposed a thermal spray coating forming apparatus for forming a thermal spray coating by spraying a sprayed material on the object to be sprayed (for example, described in Patent Document 1).

  In the thermal spray coating forming apparatus described in Patent Document 1, a wire to be fed is fed into a wire feeding hole formed in a contact chip (wire electrode), and the wire is applied to an inner wall of the wire feeding hole by a leaf spring. A structure is adopted in which plasma is generated by supplying power to the wire by pressing and contacting.

JP 2003-33877 A

  In the structure described in Patent Document 1, as described above, the wire is pressed against the inner wall of the wire feed hole by a constant spring force of the leaf spring provided inside the contact chip, and the wire is fed with power.

  For this reason, in the structure described in Patent Document 1, since the number of contact points with the wire is small, the power supply state to the wire is likely to be unstable, and the plasma arc is not stable. Further, in this structure, since the wire pressed by the leaf spring is continuously pressed against the inner wall of the wire feed hole, wear tends to progress locally, and the life of the contact tip is shortened.

  Therefore, the present invention has an object to provide a thermal spray coating forming apparatus and a method for supplying power to a wire that can increase the number of contacts between the wire and the contact tip, stabilize the plasma arc, and extend the life of the contact tip. And

  In the thermal spray coating forming apparatus of the present invention, the contact tip has a main body portion, a wire feed hole that penetrates in the axial direction of the main body portion, and a conductive material that is accommodated in the wire feed hole and comes into contact with the wire. And a plurality of power feeding members.

  In the method for feeding power to the wire of the present invention, a plurality of power feeding members having conductivity in contact with the wire are provided in the wire feeding hole penetrating the contact chip, and the wire fed to the wire feeding hole is provided. Power is supplied to the wire in contact with the power supply member.

  According to the thermal spray coating forming apparatus of the present invention, since the plurality of conductive power supply members are accommodated in the wire feed holes, the plurality of wires fed to the wire feed holes surround the periphery thereof. It comes into contact with the power supply member, and power can be supplied to the wire via the plurality of power supply members. Therefore, in the present invention, the number of contacts between the wire and the contact tip is increased, the power supply state to the wire is stabilized, and the plasma arc can be stably generated.

  On the other hand, according to the power feeding method to the wire of the present invention, when a plurality of power feeding members having conductivity are provided in the wire feeding hole penetrating the contact chip, the wire fed to the wire feeding hole is A plurality of power supply members are brought into contact with each other, and a contact state of the wires and the power supply members at a plurality of contact points stabilizes the power supply state to the wires, thereby making it possible to stably generate a plasma arc.

FIG. 1 is an overall view of a thermal spray coating forming apparatus according to a first embodiment. FIG. 2 is a view showing the contact tip of the first embodiment and the tip portion of the spray gun to which the contact tip is attached. FIG. 3 is an exploded perspective view of the contact chip according to the first embodiment. 4A and 4B are cross-sectional views showing a state in which the wire is fed into the wire feeding hole of the contact chip according to the first embodiment. FIG. 4A is a wire feeding start state, and FIG. Each state is shown. FIG. 5 is a cross-sectional view of the contact tip according to the second embodiment, showing an example in which a convex strip is provided along the axial direction of the main body on the inner surface of the wire feed hole. FIG. 6 is an exploded perspective view of the contact chip of the third embodiment, and shows an example in which the contact chip is divided into a main body part and a mounting part, and these are divided into two types. FIG. 7 is an exploded perspective view of the contact chip of the fourth embodiment, showing an example in which the contact chip is divided into two types.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

“Embodiment 1”
1 is an overall view of a thermal spray coating forming apparatus according to the first embodiment, FIG. 2 is a diagram showing a contact tip according to the first embodiment and a tip portion of a thermal spray gun to which the contact tip is attached, and FIG. 3 is an exploded view of the contact tip according to the first embodiment. FIG. 4 is a cross-sectional view showing a state in which the wire is fed to the wire feeding hole of the contact chip of Embodiment 1, (A) is a wire feeding start state, and (B) is a wire feeding state. It shows the state where the salary has advanced.

  As shown in FIG. 1, the thermal spray coating forming apparatus 1 includes a thermal spray gun 2 that injects molten metal toward an object to be sprayed, a wire supply unit 4 that supplies a wire 3 to the thermal spray gun 2, and a thermal spray gun 2. Gas supply means for supplying gas (plasma gas), air supply means for supplying atomized air to the spray gun 2, and plasma generation means for generating plasma are provided.

  The thermal spray gun 2 is attached to the tip of the main shaft 5 for turning (rotating) the thermal spray gun 2. The main shaft 5 transmits the rotational force from the motor 7 provided in the housing 6 via the timing belt 8 to rotate the thermal spray gun 2 attached to the tip thereof. In FIG. 1, the motor 7 rotates the thermal spray gun 2 in the direction indicated by the arrow X. A wire 3 serving as a thermal spray material is fed to the center of the thermal spray gun 2 through a work feed hole 9 formed through the main shaft 5 in the axial direction. The work feed hole 9 is formed as a through-hole having a diameter slightly larger than the diameter of the wire 3 in order to guide and feed the wire 3.

  The wire supply means 4 includes a plurality of feed drive rollers 11 and a feed auxiliary roller 12 that presses the wire 3 against the feed drive roller 11 with springs. The wire 3 is fed to the thermal spray gun 2 through the main shaft 5 by the driving roller 11 and the feeding auxiliary roller 12. In the wire supply means 4, the wire 3 is fed to the spray gun 2 while changing the feed speed of the wire 3 in accordance with the progress of spraying (in accordance with the increase or decrease of the spray amount).

  The gas supply unit and the air supply unit include a gas supply unit 13 that supplies plasma gas (gas), an air supply unit 14 that supplies atomized air, and a rotary joint 15 that is a path of gas air. The plasma gas supplied from the gas supply unit 13 and the atomized air supplied from the air supply unit 14 are supplied to the thermal spray gun 2 via respective supply paths (not shown) formed in the main shaft 5. It has become so.

  The plasma generating means has a power supply unit 16, one electrode connected to the positive electrode of the power supply unit 16, and the other electrode 17 connected to the negative electrode of the power supply unit 16. The other electrode 17 is fixed in the vicinity of a gas ejection hole (not shown) formed in the thermal spray gun 2. One electrode is formed of a contact tip 18 having conductivity for bringing the wire 3 into contact with the inside and feeding it.

  The thermal spray gun 2 is provided with a gas supply path for supplying plasma gas from the gas supply unit 13 to the gas ejection holes. The spray gun 2 is formed with an air supply path for supplying atomized air from the air supply unit 14 to the air ejection hole. A plurality of air ejection holes are formed so as to surround the gas ejection hole.

  As shown in FIG. 2, the contact tip 18 has a through hole 19 communicating with the work feed hole 9 formed in the main shaft 5 and a female screw portion 20 formed in the vicinity of the outlet of the through hole 19. It is detachably attached to the supply guide 21. The contact chip 18 is made of, for example, a conductive material and functions as one electrode.

  As shown in FIGS. 3 and 4, the contact chip 18 includes a mounting portion 18A that is screwed into the female screw portion 20 of the wire supply guide 21, and a main body portion 18B that is detachably attached to the mounting portion 18A. A wire feeding hole 22 that penetrates both the mounting portion 18A and the main body portion 18B in the axial direction, and a plurality of power feeding members that are accommodated in the wire feeding hole 22 and contact the wire 3 23.

  18 A of said mounting parts consist of the external thread part 24 screwed together with the internal thread part 20 of the wire supply guide 21, and the connection part 25 connected detachably with the main-body part 18B. The connecting portion 25 is formed as a cylindrical body with one surface opened, and a male screw portion 24 is formed on the other surface side. On the inner surface of the cylindrical portion of the connecting portion 25, a connecting female screw portion 26 is formed that is screwed into the main body portion 18B.

  The main body portion 18B has a cylindrical shape on the connection side with the mounting portion 18A, and a funnel shape on the wire outlet side. The main body portion 18B is formed with a connecting male screw portion 27 that is screwed with the connecting female screw portion 26 of the mounting portion 18A to couple the main body portion 18B to the mounting portion 18A.

  The wire feed hole 22 is a through-hole formed so as to penetrate the combined mounting portion 18A and main body portion 18B in the axial direction. The wire feed hole 22 includes a first feed hole 22A that penetrates the mounting portion 18A and a second feed hole 22B that penetrates the main body portion 18B. The first feeding hole 22A is formed as a straight hole having a circular cross section into which the wire 3 is loosely fitted. The second feed hole 22B includes a large-diameter hole 22B1 having a sufficiently large internal space, a conical hole 22B2 that is formed in a tip shape from the large-diameter hole 22B1 toward the wire outlet 28, and a straight hole 22B3 in the wire outlet 28. And formed by.

  The power supply member 23 is made of a steel ball having excellent conductivity such as gold, platinum, copper, or the like. The power supply member 23 has a ball shape and is accommodated in a large number in the large-diameter hole 22B1 and the conical hole 22B2 of the main body 18B. The number of power supply members 23 is set to a number that does not provide support for feeding the wire 3 and is a number that maintains the state where the power supply members 23 are in contact with each other. The diameter R1 of the power supply member 23 used here is, for example, when the diameter R2 of the wire 3 is 1.6 mm and the diameter R3 of the straight hole 22B3 of the wire outlet 28 is 1.7 mm, the straight hole 22B3 and the wire 3 The dimension is larger than 0.1 mm, which is the gap C. The diameter R1 of the power supply member 23 is smaller than the distance W between the wires 3 and the inner walls of the large-diameter hole 22B1 and the conical hole 22B2. Specifically, the diameter R1 of the power feeding member 23 is preferably 1 mm to 2 mm.

  The contact tip 18 configured as described above is attached to the thermal spray gun 2 by screwing the male screw portion 24 with the female screw portion 20 of the wire supply guide 21 and is connected to the positive electrode of the power supply portion 16. Is done. As a result, the contact chip 18 becomes one electrode.

  Next, a method for forming a thermal spray coating on the object to be sprayed using the thermal spray coating apparatus configured as described above and a method for supplying power to the wire will be described.

  First, a straight hole 22B3 formed in the wire outlet 28 of the main body portion 22B is filled with a plug made of a round bar or the like to temporarily seal the wire outlet 28, and then inside the large diameter hole 22B1 and the conical hole 22B2 of the main body portion 22B. A plurality of power supply members 23 are placed in the. Then, the contact portion 18 is completed by screwing and coupling the mounting portion 18A to the main body portion 18B. Next, the contact tip 18 is attached to the wire supply guide 21 of the thermal spray gun 2.

  When the contact tip 18 is attached to the wire supply guide 21, plasma gas is supplied from the gas supply unit 13 to the gas supply path of the thermal spray gun 2 through the main shaft 5. Similarly, atomized air is supplied from the air supply unit 14 to the air supply path of the thermal spray gun 2 via the main shaft 5. Then, the plasma gas is ejected from the gas ejection hole to the outside. On the other hand, atomized air is jetted from the air jet holes to the outside so as to surround the plasma gas jetted from the gas jet holes.

  Next, the wire 3 is fed by the wire supply means 4. The wire 3 is fed from the through hole 19 of the wire supply guide 21 provided in the spray gun 2 to the wire feed hole 22 of the contact tip 18 through the work feed hole 9 of the main shaft 5. Since the wire 3 supplied from the wire supply means 4 is used while being wound around the reel 10, the wire 3 is supplied to the wire feed hole 22 in a curved state in which the curl remains.

  The wire 3 fed to the wire feed hole 22 enters the first feed hole 22A of the mounting portion 18A. At this time, since the first feed hole 22A has a straight hole shape, the wire 3 smoothly enters the hole without being caught. Further, the wire 3 is guided straight into the back of the hole by the straight hole shape of the first feeding hole 22A.

  Then, the wire 3 passes through the plurality of power supply members 23 accommodated in the large-diameter hole 22B1 and the conical hole 22B2 of the main body portion 18B, and is fed to the back of the hole to temporarily seal the straight hole 22B3. The stopper is pushed out and protrudes outward from the wire outlet 28. Since the wire 3 protrudes outward from the wire outlet 28, the feeding member 23 is prevented from jumping out from the wire outlet 28. Since the wire 3 is wound around the reel 10 and has wrinkles, the wire 3 is curved in the wire feed hole 22 and comes into contact with the contact tip 18 at the inlet and outlet of the contact tip 18.

  Further, the wire 3 is fed while always in contact with the plurality of power supply members 23. Since the power supply member 23 is a steel ball such as copper having conductivity, the power supply member 23 comes into contact with the wire 3 while rotating by feeding the wire 3. The power supply member 23 maintains a state in which the power supply members 23 are in contact with each other and maintains a state in which at least some of the power supply members 23 are in contact with the inner wall surfaces of the large-diameter hole 22B1 and the conical hole 22B2.

  In this way, when the wire 3 comes into contact with the plurality of power supply members 23 in the wire feed hole 22 of the contact chip 18, power is supplied from the contact chip 18 to the wire 3 via the power supply member 23, and the wire 3 itself. Becomes one of the electrodes (positive electrode).

  The wire 3 jumps straight out at the wire outlet 28 through the straight hole 22B3. That is, the wire 3 is supplied to the front of the gas ejection hole.

  Then, in a state where the contact state between the contact tip 18 and the wire 3 is maintained, a voltage is applied between the contact tip 18 serving as one electrode and the other electrode 13 provided in the vicinity of the gas ejection hole to energize. Then, plasma is generated between these electrodes. The plasma gas ejected from the gas ejection holes is burned by the plasma and becomes a combustion flame.

  The wire 3 is melted by the combustion flame to become a molten metal. The molten metal becomes a sprayed frame by atomized air sprayed from the air ejection holes and is sprayed toward the sprayed material, and is formed as a sprayed coating on the surface of the sprayed material. At the time of spraying on the sprayed object, the motor 7 is driven to rotate the main shaft 5 and the spray gun 2 attached to the tip of the main shaft 5 is turned.

  The wire 3 is fed in accordance with the progress of thermal spraying on the object to be sprayed. For example, when the spraying amount increases, the wire 3 is supplied to the spraying gun 2 more, and when the spraying amount decreases, the feeding amount of the wire 3 is reduced. As described above, when the feed amount variation of the wire 3 occurs, the entrance and the exit of the wire feed hole 22 which is the contact portion between the curved wire 3 and the contact tip 18 are worn, but a plurality of power supply members 23 are formed. Since it is always in contact with the wire 3, the energization state to the wire 3 is stabilized. That is, when the plurality of power supply members 23 come into contact with the wire 3, the number of contacts between the wire 3 and the contact tip 18 can be increased, and the plasma arc can be stabilized.

  As the thermal spraying on the object to be sprayed proceeds, the power supply member 23 is contacted and worn by the feeding of the wire 3, and the size of the power supply member 23 gradually decreases, and the entire power supply member 23 is changed from the initial state of FIG. Go down to wire outlet 28 as shown in B). At this time, since the conical hole 22B2 of the wire feeding hole 22 has a funnel shape, the power feeding members 23 are lowered to the wire outlet 28 while maintaining a state where they are in contact with each other. Therefore, even if spraying is continued, the contact state between the wire 3 and the plurality of power supply members 23 is maintained, and the power supply state with respect to the wire 3 is stabilized.

  In the first embodiment, the power supply member 23 has a ball shape, but may not have a perfect spherical shape.

  According to the thermal spray coating forming apparatus of the first embodiment, since the plurality of conductive power feeding members 23 are accommodated in the wire feeding holes 22, the wires 3 fed to the wire feeding holes 22 are surrounded by the surroundings. The plurality of power supply members 23 surrounding the wire 3 are in contact with each other, and power can be supplied to the wire 3 through the plurality of power supply members 23. Therefore, in the present invention, the number of contacts between the wire 3 and the contact tip 18 is increased, the power supply state to the wire 3 is stabilized, and a plasma arc can be stably generated. Therefore, according to the first embodiment, it is possible to maintain a stable contact state of the contact tip 18 with the wire 3 fed in accordance with the progress of thermal spraying, stabilize the energized state, and extend the life of the contact tip 18. it can.

  Moreover, according to the thermal spray coating formation apparatus of Embodiment 1, since the wire feed hole 22 was made into the shape of a tip toward the wire exit 28, the state where the electric power feeding members 23 always contact each other is maintained by this tip-down shape.

  In addition, according to the thermal spray coating forming apparatus of the first embodiment, the power supply member 23 is worn and moved to the wire outlet 28 that is pointed, so that the contact state with the wire 3 is maintained. Even if the contact and the contact between the power supply members 23 become worn and become small, the wire exit 28 can be moved to maintain the contact state between the power supply members 23 and between the power supply member 23 and the wire 3. The service life can be extended.

  Further, according to the thermal spray coating forming apparatus of the first embodiment, since the power supply member 23 is a steel ball, the spherical property makes it easy to rotate by feeding the wire 3 and difficult to cause uneven wear. The contact state can be maintained.

  Further, according to the thermal spray coating forming apparatus of the first embodiment, the diameter R1 of the power supply member 23 is at least larger than the gap C between the wire outlet 28 and the wire 3 passing through the wire outlet 28. The feeding member 23 can be prevented from popping out.

  Further, according to the power feeding method to the wire of the first embodiment, a plurality of power feeding members 23 having conductivity in contact with the wire 3 are provided in the wire feeding hole 22 penetrating the contact chip 18, and the wire feeding is performed. Since the wire 3 fed to the supply hole 22 is brought into contact with the power supply member 23 to supply power to the wire 3, the number of contact points between the wire 3 and the power supply member 23 increases, so that the power supply state to the wire 3 is stabilized. . As a result, a plasma arc can be generated stably.

“Embodiment 2”
FIG. 5 is a cross-sectional view of the contact chip of the second embodiment.

  In Embodiment 2, it is set as the structure which provided the protruding item | line part 29 along the axial direction of the main-body part 18B in the inner surface of the wire feed hole 22. As shown in FIG. Specifically, the contact chip 18 has a rectangular cross-section so as to protrude from the inner surface of the large-diameter hole 22B1 and the conical hole 22B2 of the main body 18B to the center of the main body 18B and continue in the axial direction of the main body 18B. Is formed. In this embodiment, the three ridges 29 are provided at positions that divide the internal space of the main body 18B into approximately three equal parts. As a result, the wire 3 is fed to the central portion sandwiched between the three ridges 29.

  According to the thermal spray coating forming apparatus of the second embodiment, since the ridge portion 29 is provided in the internal space of the main body portion 18 along the axial direction, the power feeding member 23 contacts the ridge portion 29 and the contact point thereof. As a result, the contact state between the power supply member 23 and the contact chip 18 is stabilized, and the power supply state to the wire 3 can be further stabilized.

“Embodiment 3”
FIG. 6 is an exploded perspective view of the contact chip according to the third embodiment.

  In the third embodiment, the contact chip 18 including the mounting portion 18A and the main body portion 18B has a structure in which the contact chip 18 is divided into two along the axial direction that is the feeding direction of the wire 3. Since the other structure is the same as the structure of the contact chip 18 of the first embodiment, the same members are denoted by the same reference numerals as those used in the first embodiment, and description thereof is omitted here.

  When the two-divided contact tip 18 of the third embodiment is used, a plurality of power supply members 23 surrounding the periphery of the wire 3 fed to the wire feed hole 22 as in the contact tip 18 of the first embodiment. Can be supplied to the wire 3 via the plurality of power supply members 23. Therefore, according to the third embodiment, the number of contacts between the wire 3 and the contact tip 18 is increased by the plurality of power supply members 23, the state of power supply to the wire 3 is stabilized, and a plasma arc can be stably generated.

“Embodiment 4”
FIG. 7 is an exploded perspective view of the contact chip of the fourth embodiment.

  In the first embodiment, the contact chip 18 is composed of the mounting portion 18A and the main body portion 18B. In the fourth embodiment, the contact chip 30 is integrated from the beginning instead of being divided into the mounting portion 18A and the main body portion 18B. The contact chip 30 is divided into two in the axial direction that is the feeding direction of the wire 3. Further, the ridges 29 formed in the second embodiment are formed in the wire feeding holes 22 of the two chips 30A and 30B divided into two. In the fourth embodiment, the same components as those of the contact chip 18 of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  When the contact tip 30 of the fourth embodiment is used, the wire 3 fed to the wire feed hole 22 is in contact with a plurality of power supply members 23 surrounding the periphery thereof, as in the contact tip 18 of the first embodiment. Thus, power can be supplied to the wire 3 through the plurality of power supply members 23. Further, the protruding portion 29 formed in the wire feed hole 22 along the axial direction of the contact chip 30 stabilizes the contact state between the power supply member 23 and the contact chip 30, and further increases the power supply state to the wire 3. Can be stabilized.

  INDUSTRIAL APPLICABILITY The present invention can be used for a thermal spray coating forming apparatus that forms a thermal spray coating by spraying a molten thermal spray material toward a sprayed object.

DESCRIPTION OF SYMBOLS 1 ... Sprayed-film formation apparatus 2 ... Spray gun 3 ... Wire 4 ... Wire supply means 5 ... Main shaft 13 ... Gas supply part 14 ... Air supply part 17 ... Electrode (other electrode)
18 ... Contact chip (one electrode)
18A ... Mounting part 18B ... Main body part 20 ... Female thread part (female thread part formed in the wire supply guide)
22 ... Wire feeding hole 22A ... First feeding hole (feeding hole formed in the mounting portion)
22B ... 2nd feeding hole (feeding hole formed in the main-body part)
23 ... Power feeding member 28 ... Wire outlet 29 ... Projection

Claims (6)

A wire serving as a thermal spray material is fed into a contact tip serving as one electrode attached to the spray gun, and plasma is generated between the contact tip and the other electrode provided in the vicinity of the gas ejection hole. In the thermal spray coating forming apparatus that burns the gas injected from the holes to melt the wire, and injects the molten metal toward the thermal spray to form a thermal spray coating on the surface of the thermal spray,
The contact chip includes a main body portion, a wire feeding hole penetrating in the axial direction of the main body portion, and a plurality of power feeding members having electrical conductivity which are accommodated in the wire feeding hole and come into contact with the wire. An apparatus for forming a sprayed coating, comprising: The thermal spray coating forming apparatus according to claim 1,
The said wire feed hole is a tip shape toward the wire exit. The thermal spray coating formation apparatus characterized by the above-mentioned. The thermal spray coating apparatus according to claim 1 or 2,
The power supply member is made of a steel ball. The thermal spray coating forming apparatus according to claim 3,
A diameter of the power supply member is at least larger than a gap between a wire outlet and the wire passing through the wire outlet. The spray coating apparatus according to any one of claims 1 to 4, wherein:
A thermal spray coating forming apparatus, wherein a protrusion is provided along the axial direction of the main body on the inner surface of the wire feed hole. A wire serving as a thermal spray material is fed into a contact tip serving as one electrode attached to the spray gun, and plasma is generated between the contact tip and the other electrode provided in the vicinity of the gas ejection hole. Electric power is supplied to the wire in the thermal spray coating forming apparatus that burns the gas injected from the holes to melt the wire, and injects the molten metal toward the thermal spray to form a thermal spray coating on the surface of the thermal spray. In the method
A plurality of power supply members having conductivity that come into contact with the wire are provided in a wire feed hole that penetrates the contact chip, and the wire fed to the wire feed hole is brought into contact with the power feed member. Supplying power to the wire. A method of supplying power to the wire.

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