To provide a position sensing device capable of making accurate position sensing despite fluctuating main pressure of the air.
The position sensing device is equipped with a reference body 31 in a fixed position and a workpiece sensor 34 to abut to a workpiece W and advance and retreat together with the workpiece W relative to the reference body 31. An air feeding means 41 to pressurize the air and supply is installed between the reference body 31 and the workpiece sensor 34. A pressure sensing means 53 is installed to sense the back pressure of the air fed upon being pressurized from the air feeding means 41 to between the reference body 31 and the workpiece sensor 34. The pressure sensing means 53 senses the main pressure of the air feeding means 41 in the condition that the reference body 31 and the workpiece sensor 34 are in tight attachment to each other, senses the back pressure when the air is pressurized and supplied from the same air feeding means 41 to between the reference body 31 and the workpiece sensor 34 after moving the workpiece sensor 34 relatively, and senses the position of the workpiece sensor 34 relative to the reference body 31 from the differential pressure between the main pressure and the back pressure.
MORITA SADA
HAYAKAWA YUKIO
SANAI SHIGERU
OBAYASHI MASANORI
Satoshi Kabazawa
Tetsuya Yamada