Abstract: While a ball 14 is inserted into a hole WA of a workpiece W and is moved in the longitudinal direction of the hole WA while automatically centripetally moved, a change of back pressure of a gas injected into the hole WA is detected by a converter 30, and at the same time reflected light from a reflection member 18 provided on the ball 14 is received by a light receiving unit 22 and a change of peak position A of an amount of the received light is calculated, so as to calculate an inner diameter, straightness, and cylindricity of the hole WA, thus providing an inexpensive noncontact measuring apparatus 10 which measures the inner diameter, the straightness, and the cylindricity of the hole WA.

Abstract: A method and a device for measuring the inner diameter dimension of a work capable of easily and accurately measuring the inner diameter dimension of the work with a simple structure; the method, comprising the steps of feeding compressed air to the inner peripheral part of a master with a known inner diameter dimension to detect a back pressure, calculating back pressure characteristics showing a relation between the inner diameter dimension and the back pressure from the measured result, feeding compressed air to the inner peripheral part of the work based to be measured to detect a back pressure, and measuring the inner diameter characteristics, whereby the inner diameter dimension of the work can be measured without rotating the work.

Abstract: While a ball 14 is inserted into a hole WA of a workpiece W and is moved in the longitudinal direction of the hole WA while automatically centripetally moved, a change of back pressure of a gas injected into the hole WA is detected by a converter 30, and at the same time reflected light from a reflection member 18 provided on the ball 14 is received by a light receiving unit 22 and a change of peak position A of an amount of the received light is calculated, so as to calculate an inner diameter, straightness, and cylindricity of the hole WA, thus providing an inexpensive noncontact measuring apparatus 10 which measures the inner diameter, the straightness, and the cylindricity of the hole WA.

Abstract: A method and a device for measuring the inner diameter dimension of a work capable of easily and accurately measuring the inner diameter dimension of the work with a simple structure; the method, comprising the steps of feeding compressed air to the inner peripheral part of a master with a known inner diameter dimension to detect a back pressure, calculating back pressure characteristics showing a relation between the inner diameter dimension and the back pressure from the measured result, feeding compressed air to the inner peripheral part of the work based to be measured to detect a back pressure, and measuring the inner diameter characteristics, whereby the inner diameter dimension of the work can be measured without rotating the work.

Abstract: The inside diameter measuring method and apparatus are capable of making accurate measurement. In the inside diameter measuring method of measuring an inside diameter of a cylindrical work by supplying compressed air from one end of the work and by detecting a back pressure of the compressed air, a correction amount of measured value of the inside diameter according to a length of the work is obtained in advance by determining a change of measured value of the inside diameter with respect to a change of the length of the work, whereby the measured value of the inside diameter is corrected according to the length of the work. Thereby, even in the case where a plurality of works having a different length are measured, accurate measurement can always be made.

Abstract: The inside diameter measuring method and apparatus are capable of making accurate measurement. In the inside diameter measuring method of measuring an inside diameter of a cylindrical work by supplying compressed air from one end of the work and by detecting a back pressure of the compressed air, a correction amount of measured value of the inside diameter according to a length of the work is obtained in advance by determining a change of measured value of the inside diameter with respect to a change of the length of the work, whereby the measured value of the inside diameter is corrected according to the length of the work. Thereby, even in the case where a plurality of works having a different length are measured, accurate measurement can always be made.