Patent ID: 9358559
Filing Date: 2016-06-07
CPC Classification: B05B

Claim Text:
1. A spray gun for mixing and atomizing a coating material flow and an air flow in the atmosphere, the spray gun comprising: a body having a gun barrel; a coating material nozzle disposed on a tip end side of the gun barrel, ejecting the coating material flow from a coating material ejection opening formed on a tip end surface thereof; and an air cap disposed on the tip end side of the gun barrel to surround a tip end portion of the coating material nozzle, the air cap defining a ring-shaped slit between an inner peripheral surface thereof and an outer peripheral surface of the tip end portion of the coating material nozzle to allow the air flow to be ejected therethrough, wherein the tip end portion of the coating material nozzle has on the tip end surface thereof an inner guide wall that widens along an axis extending in a first direction from an inner periphery of the coating material ejection opening toward a downstream facing surface of the coating material nozzle, the downstream facing surface extending in a second direction perpendicular to the first direction, the guide wall controlling the coating material flow ejected from the coating material ejection opening, the tip end portion also having on the outer peripheral surface thereof a plurality of V-shaped grooves channeled in a longitudinal direction from a rear end side thereof in a predetermined position toward the downstream facing surface, the V-shaped grooves extending through the tip end portion to define V-shaped notches in the inner guide wall, the V-shaped grooves inducing a part of the air flow ahead of the coating material ejection opening, wherein at least one of the V-shaped grooves has, in a triangle shaped cross section defined by contours crossing the guide wall, a height h in the range of 0.5 mm to 2.5 mm and an opening angle g of a bottom vertex in the range of 20 degrees to 100 degrees, and wherein the V-shaped grooves are formed with bottom portions located on a circle larger in diameter than an inner periphery of the coating material ejection opening on the guide wall of the coating material nozzle.