JP2005272879A - Sprayed coating depositing method, and thermal spraying gun device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal spraying gun device capable of preventing a wire with winding habit from being fed in a deviated condition in one direction at a melting point, reducing deviation of a sprayed coating on an inner surface of a cylinder, and unifying the thickness of the sprayed coating. <P>SOLUTION: The thermal spraying gun device comprises feed rollers 6 and 7 to continuously feed a wire 3 as a thermal spraying material, a thermal spraying gun 5 comprising a thermal spraying gun body 8 to feed the wire 3 to a feed hole 10 penetrating in the axial direction and a thermal spraying head 9 which is rotatably mounted on a tip of the thermal spraying gun body 8, and deposits a sprayed coating 4 by spraying droplet of the wire melted with combustion flame 14 against an inner surface 1a of a cylinder bore 1 by spraying gas, and inclined projections 16 to turn the wire 3 around the axial direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermal spray coating forming method and a thermal spray gun apparatus for forming a thermal spray coating on an inner surface of a cylindrical body, and more particularly to a technique for feeding a wire, which is a thermal spray material, to a thermal spray gun.

  As an apparatus for forming an alloy sprayed layer on the cylinder bore inner wall of an engine block, for example, a high temperature flame is made with acetylene, propane and oxygen, and a thermal spray material (spray wire) is fed into this at a constant speed. There has been proposed a spray gun device that forms a sprayed alloy layer (sprayed coating) by spraying sprayed material droplets (melted sprayed material droplets) on the inner wall surface at high speed from the nozzle. (For example, refer to Patent Document 1).

  In this type of thermal spray gun apparatus, the wire wound around the drum reel is placed behind the thermal spray gun, the wire is fed out from the drum reel using a feed roller, and the fed wire is continuously supplied to the thermal spray gun. A supply mechanism is provided.

  By the way, since the wire is delivered in a drum-wound state at the time of delivery, it has a unidirectional winding rod. For this reason, when supplying a wire from the back of the spray gun, the center of the spray gun and the tip of the wire are displaced at the melting point at the tip of the spray gun.

  If the wire deviates from the center of the spray gun in a certain direction at the melting point, a deviation occurs in the molten state at the tip of the wire, and a deviation occurs in which the thermal spray coating in only one direction on the inner surface of the cylinder is thickened. Therefore, in order to ensure the necessary film thickness of the sprayed coating in the thinned portion, the amount of wire must be used more than the normal usage amount, resulting in a worsening of material costs. Further, since the center position of the inner diameter of the cylinder bore is shifted due to the deviation of the film thickness, the position of the cylinder bore is shifted after the final machining of the engine.

Therefore, as a countermeasure against the bending of the wire, for example, protrusions with a wire surface roughness Ra of 0.4 to 3.0 μm and a maximum height Ry of 15 μm or less are formed at intervals of 150 μm or less, and a liquid lubricant is formed on the wire surface. The technique which apply | coated this is known (for example, refer patent document 2). In addition, a technique in which grooves are formed on the peripheral surface of the wire at a substantially constant pitch is also known (for example, see Patent Document 3).
JP-A-7-62518 (Pages 2 and 3 and FIG. 1) JP-A-8-197278 (Pages 2 and 3; FIGS. 1 and 3) Japanese Patent Application Laid-Open No. 5-115994 (pages 3 and 4, FIG. 1, FIG. 5 and FIG. 6)

  However, with the technique described in Patent Document 2, it is possible to improve the wire feedability, but it is not possible to correct the positional deviation at the tip of the spray gun due to the curved wire. The technique described in Patent Document 3 is intended to improve the flexibility of a wire having a large diameter, and this technique cannot correct the misalignment of the tip of the spray gun.

  Therefore, the present invention prevents the wire with the curl from being fed in a state shifted in one direction at the melting point, reduces the unevenness of the spray coating on the inner surface of the cylinder, and reduces the thickness of the spray coating. It aims at providing the formation method and thermal spray gun apparatus of the thermal spray coating which can be made uniform.

  In order to solve the above-described problems, the method for forming a thermal spray coating of the present invention feeds a wire, which is a thermal spray material, to a feed hole formed in the thermal spray gun while rotating the wire in the direction around the axis. I will let you.

  The spray gun device of the present invention is rotatably attached to the spray gun main body having a feed means for feeding the wire continuously, a feed hole through which the wire is fed, and the spray gun main body. And a wire rotating means for rotating the wire in the direction around the axis.

  According to the method for forming a sprayed coating of the present invention, the wire is fed in the feed hole of the spray gun while rotating the wire in the direction around the axis, so that the curved wire is always fed in a state shifted in one direction at the melting point. Can be prevented. Therefore, since the wires are randomly dispersed without being biased in one direction, the bias that the thickness of the inner surface of the cylinder is increased only in one direction is reduced, and the thickness of the sprayed coating can be made uniform.

  According to the thermal spray gun apparatus of the present invention, since the wire rotating means for rotating the wire in the direction around the axis is provided, it is possible to prevent the curved wire from being fed in a state that is always shifted in one direction at the melting point, The film thickness of the film can be made uniform.

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

[First Embodiment]
First, after describing a thermal spray gun apparatus, the formation method of the thermal spray coating using this thermal spray gun apparatus is demonstrated.

  FIG. 1 is a cross-sectional view of the thermal spray gun apparatus of the first embodiment, FIG. 2A is a perspective view showing an example of a wire rotating means in which inclined protrusions are formed on the roller surface, and FIG. FIG. 3A is a perspective view showing an example of a wire rotating means arranged obliquely with respect to the roller of FIG. 3, FIG. 3A is a view showing a state of splashing droplets when the wire is rotated around the axis, and FIG. ) Is a diagram showing the state of droplet spraying when the wire is sprayed upward without rotating the wire around the axis, and FIG. 3C is a spray when spraying downward without rotating the wire around the shaft. FIG. 4 is a main part enlarged cross-sectional view showing an example of a wire rotating means in which a guide is engaged with a spiral groove formed on a peripheral surface of a wire and the wire is rotated around an axis. .

  As shown in FIG. 1, the thermal spray gun apparatus moves, for example, a center hole 2 of a cylinder bore (cylindrical body) 1 in a cylinder block of an automobile engine from one end side to the other end side in the direction of the arrow X, and burns from a nozzle tip. A spray gun 5 that forms a spray coating 4 by spraying droplets obtained by melting the wire 3 that is a spray material on the inner surface 1a, and a feed roller 6 that is a feed means for feeding the wire 3 to the spray gun 5. , 7.

  The thermal spray gun 5 includes a thermal spray gun main body 8 formed as a cylindrical body, and a thermal spray head 9 that is rotatably attached to the tip of the thermal spray gun main body 8. The spray gun body 8 has a feed hole 10 formed so as to penetrate in the axial direction. The feed hole 10 is formed as a through hole having a circular cross section having a size that allows the wire 3 to be inserted from the one end 8 a to the other end 8 b of the spray gun body 8. The spray gun main body 8 is provided with argon gas (Ar gas) or hydrogen gas (H 2 gas) used for generating a combustion flame as an auxiliary gas, and for supplying the auxiliary gas to the spray head 9. Gas supply holes (not shown) are formed.

  The thermal spraying head 9 forms the thermal spray coating 4 by melting the supplied wire 3 with a combustion flame, spraying the molten droplets of the molten wire 3 on the inner surface 1 a of the cylinder bore 1. The thermal spraying head 9 is rotatable in the direction indicated by the arrow A in FIG. 1 with respect to the thermal spray gun body 8, and can spray spray droplets uniformly on the inner surface 1a of the cylinder bore 1 having a cylindrical shape. Yes.

  As shown in FIG. 3, the thermal spraying head 9 includes a central hole 11 that communicates with a feeding hole 10 formed in the thermal spray gun body 8 and feeds the wire 3 forward, and a plurality of peripheral holes around the central hole 11. A head portion 13 having the provided auxiliary gas ejection holes 12 is provided. The auxiliary gas is ejected from the auxiliary gas ejection hole 12, and the auxiliary flame is ignited, whereby the combustion flame 14 is discharged forward. The wire 3 supplied from the center hole 11 is melted by the combustion flame 14 and becomes droplets 18 for forming the sprayed coating 4.

  Further, the spraying head 9 is formed with an ejection portion 15 having an ejection hole (not shown) for ejecting droplets toward the inner surface 1a of the cylinder bore 1. The ejecting portion 15 is formed as a protruding portion that protrudes further forward than the head portion 13. The ejecting portion 15 ejects gas from the oblique direction to the droplet 18 to spray the droplet 18 on the inner surface 1 a of the cylinder bore 1.

  As shown in FIG. 1, the feed rollers 6 and 7 are rotatably provided on the one end 8 a side of the spray gun body 8 on the side opposite to the spray head 9. The feed rollers 6 and 7 are rotated by a drive source (not shown) to supply the wire 3 wound around the drum reel to the feed hole 10 of the spray gun 5. As shown in FIG. 2 (A), the feeding rollers 6 and 7 are formed as a cylindrical body having a low height, and are disposed opposite to each other with the wire 3 interposed therebetween.

  A plurality of inclined protrusions 16 formed in a spiral shape for rotating the wire 3 in the direction around the axis indicated by the arrow R in FIG. The wire 3 sandwiched between the pair of feeding rollers 6 and 7 having the inclined protrusion 16 formed in a spiral shape is rotated in the direction around the axis by the action of the inclined inclination protrusion 16. That is, the feed rollers 6 and 7 have both a function of feeding the wire 3 from the drum reel and feeding it to the spray gun 5 and a function of rotating the wire 3 in the direction around the axis.

  The height and the inclination angle of the inclined protrusion 16 are determined according to various parameters such as the diameter of the wire 3, the feeding speed, and the number of rotations of the feeding rollers 6 and 7. For example, the length of the spray gun 5 is 500 mm, the rotational speed of the spray head 9 is 2000 rpm, the wire passage diameter of the spray gun 5 (diameter of the feed hole 10) is Φ3.3, the diameter of the wire 3 is Φ3.2, the wire 3 is 150 mm / min, the rotation speed of the feed rollers 6 and 7 is 2 rpm, and the rotation speed of the wire 3 is 20 rpm, the height of the inclined protrusion 16 is 1 mm, the inclination angle (inclination protrusion with respect to the axis) 16) is preferably 45 degrees.

  FIG. 2B shows an example in which the wire 3 is rotated in the direction around the axis by arranging one feeding roller 6 obliquely with respect to the other feeding roller 7. A plurality of anti-slip protrusions 17 for reliably feeding the wire 3 are formed on the surfaces of the feed rollers 6 and 7. These anti-slip protrusions 17 are formed as protrusions having a low height that are inclined with respect to the axis. Thus, if one feeding roller 6 is disposed obliquely with respect to the other feeding roller 7, the wire 3 can be rotated in the direction around the axis indicated by the arrow R in FIG.

  Next, a method for forming the sprayed coating 4 on the inner surface 1a of the cylinder bore 1 using the spray gun apparatus configured as described above will be described. First, the feed rollers 6 and 7 are rotated, and an auxiliary gas is introduced into the spray gun 5 simultaneously with or before the rotation of the feed rollers 6 and 7 to generate the combustion flame 14. When the feed rollers 6 and 7 are driven, the wire 3 wound around the drum reel is fed out from the drum reel and fed to the feed hole 10 of the spray gun body 8. Along with this feeding, the wire 3 is rotated around the axis by the pair of feeding rollers 6 and 7.

  The wire 3 fed from the spray gun main body 8 to the spray head 9 has a curl wound in one direction by being wound on the drum reel. In this state, when the wire 3 is melted by the combustion flame 14 and the melted droplet 18 is sprayed onto the inner surface 1a of the cylinder bore 1, the upper droplet 18 with a curl as shown in FIG. Is high (indicated by dark shading), and the concentration of the droplet 18 on the opposite side as shown in FIG. 3C is low (indicated by light shading). Therefore, the film thickness of the sprayed coating 4 formed on the inner surface 1a of the cylinder bore 1 varies.

  However, in the present embodiment, since the wire 3 is rotated in the direction around the axis, the curved wire 3 is always fed in a state shifted in one direction at the melting point in front of the head portion 13. Is prevented. Therefore, as shown in FIG. 3A, since the wires 3 are randomly dispersed without being biased in one direction, the concentration of the droplets 18 becomes uniform over the entire rotation direction of the wires 3. Further, the thermal spraying head 9 rotates asynchronously with the wire 3 so that gas is not applied to the wire tip portion that is always displaced in one direction with a curl. For this reason, the molten state of the wire tip is made uniform, and a uniform sprayed coating 4 can be formed on the inner surface 1a of the cylinder bore 1.

  As described above, according to the present embodiment, the wire 3 is rotated in the direction around the axis, and the rotation of the wire 3 and the rotation of the thermal spray head 9 are made asynchronous so that the thermal spray coating 4 is further improved. The film thickness can be made uniform.

  Moreover, according to this Embodiment, since the driving force of the feed rollers 6 and 7 which supply the wire 3 to the spray gun 5 is used for the rotation of the wire 3 in the direction around the axis, Since no specific power is required and a certain rotation amount is added to the supply amount, the structure of the thermal spray gun apparatus can be simplified.

  Further, according to the present embodiment, since the inclined protrusion 16 is formed on the surface of the feeding rollers 6 and 7 and the wire 3 is rotated around the axis by the inclined protrusion 16, the structure is simple. And the apparatus cost can be reduced.

  In addition, according to the present embodiment, one of the feeding rollers 6 is disposed obliquely with respect to the other of the feeding rollers 7, and the wire 3 is rotated in the direction around the axis. It can be configured, and the cost is not increased.

  While the first embodiment has been described above, the present invention can be variously modified without being limited to the above-described embodiment.

  For example, as the wire rotating means for rotating the wire 3 in the direction around the axis, as shown in FIG. 4, the spiral groove 19 formed on the peripheral surface of the wire 3 and the inner surface of the feeding hole 10 are provided so as to protrude from the spiral. It consists of a guide 20 with a sharp tip engaged with the groove 19. According to this wire rotating means, the wire 3 sent to the tip of the thermal spray head 9 is rotated around the axis along the spiral groove 19 by the tip of the guide 20 entering the spiral groove 19 formed on the peripheral surface thereof. Rotate in the direction.

  Thus, if it is set as the structure which engages the guide 20 provided in the feed hole 10 in the spiral groove 19 formed in the surrounding surface of the wire 3, and makes it the structure which rotates the wire 3 in the periphery of an axis | shaft, it will be special for wire rotation. Therefore, the spray gun structure can be simplified because a constant amount of rotation is added to the supply amount without requiring any motive power.

  Further, in this embodiment, the spiral groove 19 formed on the surface of the wire 3 increases the surface area of the wire 3 and promotes melting of the wire 3 at the same combustion amount as compared to the wire without groove. The droplets become finer, the film thickness of the sprayed coating 4 becomes more uniform, and a dense coating can be obtained.

[Second Embodiment]
FIG. 5 is a cross-sectional view of the spray gun apparatus of the second embodiment, FIG. 6 is an enlarged cross-sectional view of a main portion of a portion where a guide member for guiding the feeding of the wire is provided in the feeding hole, and FIG. FIG. 8 is a graph showing the relationship between the wire tip deviation amount and the deviation of the film thickness of the thermal spray coating, and FIG. 9 is the bore position deviation after spraying and the bore position after honing. It is a graph which shows the relationship of deviation | shift amount.

  In the thermal spray gun apparatus according to the second embodiment, as shown in FIGS. 5 and 6, a guide member 21 that guides the feeding of the wire 3 is provided in the feeding hole 10 in the vicinity of the thermal spraying head 9. . The guide member 21 is formed as a ring having an insertion hole 22 through which the wire 3 is inserted at the center, and is fitted into the feeding hole 10.

  The wire 3 fed to the feed hole 10 is a divided wire cut to a predetermined length. The length of the wire 3 to be divided is preferably set to a length corresponding to the amount of droplets of the thermal spray coating 4 to be formed in one cylinder bore, for example.

  As described above, according to the second embodiment, the divided wire 3 is supplied to the feed hole 10, so that the position difference between the center of the spray gun and the tip of the wire due to the curl generated by being wound around the drum reel. Can be reduced. Therefore, as shown in FIG. 5, the droplets 18 of the wire 3 melted by the combustion flame 14 can be sprayed uniformly on the inner surface 1 a of the cylinder bore 1. As a result, the unevenness of the sprayed coating 4 formed on the inner surface 1a of the cylinder bore 1 can be greatly reduced.

  In contrast, when the wire 3 is continuously fed to the feed hole 10 without being divided, as shown in FIG. The concentration of the droplet 18 is high, and the concentration of the droplet 18 in the other direction is thin. For this reason, the film thickness of the thermal spray coating 4 formed on the inner surface 1a of the cylinder bore 1 is uneven and non-uniform.

  Further, according to the second embodiment, since the wire 3 is held by the guide member 21 provided in front of the feeding hole 10, the wire 3 which is biased in one direction is corrected so that the center of the spray gun and the tip of the wire are corrected. Can be further reduced. Thereby, the film thickness of the thermal spray coating 4 can be made uniform with respect to the entire circumferential surface of the cylinder bore 1.

  The place where the guide member 21 is disposed is preferably in front of the thermal spraying head 9. If it is behind, it becomes difficult to correct the wire 3 with the curl. For example, the length of the spray gun 5 is 500 mm, the diameter of the feed hole 10 (wire passage diameter of the spray gun 5) is Φ3.3, the diameter of the wire 3 is Φ3.2, and the center deviation amount in the wire curvature due to the curl is When the guide member 21 is provided in the vicinity of the feed rollers 6 and 7 at 13 mm per meter, the deviation amount between the wire tip position at the melting point of the wire 3 and the gun center is 0.3 mm, The deviation amount of the thermal spray coating 4 is about 120 μm from FIG.

  On the other hand, when the wire 3 is divided to have a length of 250 mm and the guide member 21 is arranged at the center of the spray gun body 8, the amount of deviation of the tip of the spray gun is 0.15 mm, and the amount of deviation of the spray coating 4 is Is significantly reduced to about 50 μm from FIG.

  Although specific embodiments to which the present invention is applied have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made.

  In the second embodiment, the guide member 21 has a ring shape. However, the guide member 21 is not limited to the ring shape as long as the wire 3 can be guided. Further, as described above, the guide member 21 may be provided between the thermal spray gun main body 8 and the thermal spraying head 9.

It is sectional drawing of the thermal spray gun apparatus of 1st Embodiment. In the thermal spray gun apparatus of 1st Embodiment, (A) is a perspective view which shows an example of the wire rotation means which formed the inclination protrusion in the roller surface, (B) is slanting one roller with respect to the other roller. It is a perspective view which shows an example of the arrange | positioned wire rotation means. In the thermal spray gun apparatus of the first embodiment, (A) is a diagram showing the state of sprayed droplets when the wire is rotated in the direction around the axis, and (B) is a state where the wire is not rotated in the direction around the axis. The figure which shows the dispersion state of the droplet when spraying upwards, (C) is a figure which shows the dispersion state of the droplet when spraying downward without rotating a wire around an axis. In the thermal spray gun apparatus of 1st Embodiment, it is a principal part expanded sectional view which shows an example of the wire rotation means which engaged the guide with the spiral groove formed in the surrounding surface of the wire, and rotated the wire around the axis. is there. It is sectional drawing of the thermal spray gun apparatus of 2nd Embodiment. In the thermal spray gun apparatus of 2nd Embodiment, it is the principal part expanded sectional view of the part by which the guide member which guides supply of a wire was provided in the supply hole. It is sectional drawing of the thermal spray gun apparatus of the conventional structure without a guide member. It is a graph which shows the relationship between the wire tip shift | offset | difference amount and the deviation of the film thickness of a thermal spray coating. It is a graph which shows the relationship between the bore position shift amount after thermal spraying, and the bore position shift amount after honing.

Explanation of symbols

1 ... Cylinder block (cylindrical body)
1a ... inner surface 3 ... wire (spraying material)
4 ... Thermal spray coating 5 ... Thermal spray gun 6, 7 ... Feed roller (feed means)
8 ... Spray gun body 9 ... Thermal spray head 10 ... Feeding hole 14 ... Combustion flame 16 ... Inclined protrusion (wire rotating means)
18 ... droplet 19 ... spiral groove 20 ... guide 21 ... guide member

Claims (9)

The wire that is the thermal spray material is continuously fed by the feeding means to the feed hole formed in the thermal spray gun, and the fed wire is melted by the combustion flame at the tip of the thermal spray gun, and the thermal spray provided at the tip of the thermal spray gun. In the method for forming a thermal spray coating, the gas droplets are jetted while rotating the head, and the molten droplets are sprayed onto the inner surface of the cylindrical body to form the thermal spray coating.
A method for forming a thermal spray coating, wherein the wire is fed to the feeding hole while rotating the wire in a direction around an axis. A method for forming a thermal spray coating according to claim 1,
A method for forming a thermal spray coating, wherein the wire is rotated in a direction around an axis using a driving force of the feeding means. The wire that is the thermal spray material is continuously fed by the feeding means to the feed hole formed in the thermal spray gun, and the fed wire is melted by the combustion flame at the tip of the thermal spray gun, and the thermal spray provided at the tip of the thermal spray gun. In the method for forming a thermal spray coating, the gas droplets are jetted while rotating the head, and the molten droplets are sprayed onto the inner surface of the cylindrical body to form the thermal spray coating.
A method for forming a thermal spray coating, wherein a parting wire obtained by cutting the wire into a predetermined length is fed into a feeding hole of the thermal spray gun. A feeding means for continuously feeding the wire which is a thermal spray material;
A spray gun body that feeds the wire to a feed hole formed so as to penetrate in the axial direction, and a droplet of the wire that is rotatably attached to the tip of the spray gun body and melted by a combustion flame, A thermal spraying gun comprising: a thermal spraying head for forming a thermal spray coating by jetting gas and spraying the inner surface of the cylindrical body;
A thermal spray gun apparatus comprising: a wire rotating unit that rotates the wire in a direction around an axis. The thermal spray gun apparatus according to claim 4,
The spray gun apparatus, wherein the wire and the spray gun are rotated asynchronously. The thermal spray gun apparatus according to claim 4 or 5,
The feeding means comprises a pair of rollers arranged on both sides of the wire,
The said wire rotation means consists of the inclination protrusion formed in the surface of the said roller which rotates the said wire to the periphery of an axis | shaft. The thermal spray gun apparatus characterized by the above-mentioned. The thermal spray gun apparatus according to claim 4 or 5,
The feeding means comprises a pair of rollers arranged on both sides of the wire,
The said wire rotation means has arrange | positioned one roller diagonally with respect to the other roller. The thermal spray gun apparatus characterized by the above-mentioned. The thermal spray gun apparatus according to claim 4 or 5,
The wire rotating means includes a spiral groove formed on a peripheral surface of the wire, and a guide that protrudes from an inner surface of the feeding hole and engages with the spiral groove. . A spray gun apparatus according to any one of claims 4 to 8, comprising:
The spray gun apparatus, wherein a guide member for guiding the feeding of the wire is provided in the feeding hole.