To provide a method of forming a sprayed coating where only surplus thermal spraying powder suspending in the central hole of a cylindrical body can be exhausted to the outside of the cylindrical body, and a sprayed coating having no variation in film thickness and having satisfactory surface roughness can be formed.
While a thermal spraying gun 3 inserted into the central hole 2 of a cylinder bore 1 is moved from one end side to the other end side, droplets 13 obtained by melting thermal spraying powder with plasma flame are sprayed on the inside face 1a to form a sprayed coating 14. Then, the front of the thermal spraying gun 3 is provided with an exhausting means 5 with a duplex tube structure of a first exhaust tube 7 and a second exhaust tube 8, and surplus thermal spraying powder 4 suspending in the central hole 2 of the cylinder bore 1 is exhausted to the outside of the cylinder bore 1 by the exhausting means 5. In this case, a difference is made in suction force between the part near the inside face 1a of the cylinder bore 1 and the central part by the exhausting means 5. At this time, the suction force in the second exhaust tube 8 is made higher than that in the first exhaust tube 7 sucking the part near the inside face 1a of the cylinder bore 1.
MATSUYAMA HIDENOBU
SHIMIZU AKIRA
KIYOHARA SHINJI
Iwa Saki Kokuni
Akira Kurihara
Kawamata Sumio
Masakazu Ito
Shunichi Takahashi
Toshio Takamatsu
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