Thermal spraying apparatus

Abstract

A thermal spraying apparatus that is capable of effectively preventing the adhesion of spray fumes to unsprayed regions of a bore surface during arc spraying is provided. To this end, a thermal spraying apparatus 10 comprises a spray gun 6 that moves within a cylinder bore. The spray gun 6 has at one end thereof a first discharge opening (atomizing nozzle 62 ) that faces a direction that is orthogonal to the movement direction, has a second discharge opening (auxiliary nozzle 63 ) that faces a direction that is orthogonal to the nozzle 62, and has, at a predetermined region located further to the side in the movement direction of the spray gun 6 than the nozzle 62, third discharge openings (fume adhesion prevention nozzles 65 ) for discharging a fluid and that faces the same direction as the nozzle 62. A droplet, which forms as an arc spray wire material melts at the tip of the spray gun 6, is stretched with auxiliary air A 1 . By blowing atomizing air A 2 onto the droplet, spray particles are formed and sprayed onto the bore surface. At the same time, fume adhesion prevention air A 3 is blown towards the cylinder bore surface in synchrony with the spraying of the spray particles.

1 . A thermal spraying apparatus that forms an arc spray coating on a surface of a cylinder bore, the thermal spraying apparatus characterized in that:
 the thermal spraying apparatus at least comprises rotation control means, movement control means, and a spray gun that is rotated by the rotation control means and that has at one end thereof a first discharge opening facing a direction that is orthogonal to the movement direction of the spray gun and that further has a second discharge opening facing a direction that is orthogonal to the direction that the first discharge opening faces;   in the spray gun, a third discharge opening for discharging a fluid and that faces the same direction as the first discharge opening is provided at a predetermined region that is located further to the side in the movement direction of the spray gun than the first discharge opening;   atomizing air is discharged from the first discharge opening and auxiliary air is discharged from the second discharge opening; and   when the first discharge opening moves within the cylinder bore in the direction of the axial center thereof by means of the movement control means while the spray gun is in a rotating posture by means of the rotation control means, the fluid is blown towards the bore surface in synchrony with the spraying of spray particles to the cylinder bore surface.   
   
   
       2 . The thermal spraying apparatus according to  claim 1  characterized in that the distance from a deposition center of the arc spray coating sprayed and deposited on the bore surface to the intersection between the axial center line extending from the third discharge opening and the bore surface is set within a range of 10 to 40 mm.