Piping device and cutting oil coater using the same

A piping device comprising:

• an oil supply path;
• a narrower path connected with the oil supply path and having an inside diameter smaller than that of the oil supply path;
• an air space into which the oil is discharged from the narrower path;
• a wall defining the air space having a recess;
• an
• a plurality of branch paths into which the oil having impinged on the recess flows, wherein a vertex of the recess and an end of the narrower path face each other;
• and
• wherein at least one of the plurality of branch paths has an inside diameter different from an inside diameter of the other paths.

A piping device, for use in a cutting oil coater for coating a cutting oil over cutting objects and tools in a cutting process, comprising:

• an oil supply path;
• an oil tube, from which oil is discharged in a liquid state from an end of said oil tube;
• a gas tube, inserted in said oil tube, and connected to said oil supply path, for discharging a gas through an end of said gas tube;
• such that oil discharged from said end of said oil tube and gas discharged from said end of said gas tube are mixed in said oil supply path, wherein said oil is changed from a liquid state to a droplet state;
• a narrower path connected with the oil supply path and having an inside diameter smaller than that of the oil supply path;
• an air space into which the oil is discharged from the narrower path;
• such that a flow velocity of said oil in said droplet state, from said oil supply path, increases as said oil in said droplet state flows into said narrower path, whereupon it diffuses into said air space and is changed into an oil spray;
• a wall defining the air space, having a recess;
• and
• a plurality of branch paths into which the oil having impinged on the recess flows,
• wherein a vertex of the recess and an end of the narrower path face each other.

A piping device comprising:

• an oil supply path;
• a narrower path connected with the oil supply path and having an inside diameter smaller than that of the oil supply path;
• an air space into which the oil is dishcarged from the narrower path;
• a wall defining the air space having a recess, in a shape of a polygonal pyramid;
• and
• a plurality of branch paths into which the oil having impinged on the recess flows;
• wherein a vertex of the recess and an end of the narrower path face each other;
• and
• wherein said air space, in the shape of a polygonal pyramid, has a same number of inclined surfaces as a number of the branch paths.