Oil/air lubrication system
There is provided an oil/air lubrication system capable of surely detecting lubrication oil in oil/air adapted to be fed into a rotary portion of a machine tool. A detection means which is provided to a pipe line in the vicinity of a mixing valve, just downstream of the mixing valve, is adapted to detect a flow of lubrication oil with the use of electromagnetic waves, and accordingly, a flow of air/oil can be accurately detected, irrespective of vibration of the machine tool, influence by the gravity, variation in the flow and a length of the pipe line from the mixing valve to the machine tool, and irrespective of a viscosity of the lubrication oil, and as well, irrespective of the installation of the detecting portion of the detecting means in a vertical direction or a horizontal direction.
1. An oil/air lubrication system for lubricating a rotary portion of a machine tool with oil/air, said system comprising:
a pipe line for feeding the oil/air into the rotary portion of the machine tool;
a mixing valve connected to the pipe line, for mixing microscopic lubrication oil and compressed air with each other so as to form the oil/air, and for intermittently discharging the oil/air;
a detecting means provided to the pipe line in the vicinity of the mixing valve, just downstream of the mixing valve, for detecting a flow in mass of the lubrication oil just after being discharged from the mixing valve, with the use of electromagnetic waves having a frequency of 2.45 GHz or 0.93 GHz;
an abnormality signal output means for outputting an abnormality signal when the detection means fails to detect the flow of lubrication oil; and
wherein the detection means is removably attached to the pipeline so as to cause a detecting portion of the detection means to surround the outer periphery of the pipeline.
2. An oil/air lubrication system as set forth in claim 1 , wherein the detection means is provided to the pipe line in a range having a distance from the mixing valve to a position where the lubrication oil flows in mass in the pipe line, the lubrication oil having a droplet size which is maintained to be greater than 0.6 mm.
3. An oil/air lubrication system as set forth in claim 1 or 2 , characterized in that the pipe line is made of a resin group material or an inorganic material, said resin group material being any one of nylon, ether group polyurethane, PTFE, acrylic resin, polycarbonate, vinylchloride or silicone rubber.