JPS6047909A - Measuring method of changing position and dimension by using sound - Google Patents

Abstract

PURPOSE:To measure a changing position and dimension, by blowing air into an open end or a vent provided in an outer peripheral surface so as to generate a sound, and by measuring the changes in the frequency, sound pressure level and noise level of the generated sound which are caused by a change in the distance between the vent and an object to be measured. CONSTITUTION:An object 1 changing its position to the right and left is put in proximity to the open end of a small pipe 2 or a vent opened in the outer peripheral surface thereof, and air under a prescribed pressure is blown from a nozzle 4 into said open end or vent to generate a sound. The frequency, sound pressure level or noise level of the sound is known from a microphone 9 set in the vicinity of the end of the pipe generating the sound, through a sound level meter by a spectrum analyzer 11. When a distance between the object 1 and the pipe 2 changes, the frequency, sound pressure level and noise level of the sound also change. Accordingly, the desired distance can be determined by measuring the frequency, sound pressure level or noise level of the sound.

Description

DETAILED DESCRIPTION OF THE INVENTION Conventional methods for measuring changing positions and methods have used dial indicators, calipers, micrometers, laser beams, differential transformers, strain gauges, etc. However, some of these quantitative methods have drawbacks such as low measurement accuracy, cannot be used for 11 constants of a one-rotation object, are expensive, and require skill. It was devised for the purpose of eliminating defects,
This method uses sound U to measure changing positions and dimensions. This method has high precision, can be used even for rotating objects, is inexpensive, and does not require skill. It i11 field of minute movement of objects, ill of thermal deformation of machines
Compared to conventional techniques, the industrial application fields are extremely wide, such as the field of 411 constant determination of the coefficient of thermal expansion of materials, and the field of sensors for sensing displacement.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings, in which an object (1) whose position changes from side to side is placed in close proximity to the open end of a small tube (2) or a hole drilled in its outer circumferential surface. (3) is a support for the limb canal. Insert the nozzle (
4) Blowing air at a constant pressure from a source generates sound. The air passes through the filter (6) from Konopurenots (5), and the pressure is changed by the pressure regulator (7) until the pressure i! 1 (81
Read the pressure value. The frequency, sound pressure level, or noise level of the sound can be determined by the spectrum analyzer (11) through the noise signal 1 (]O) from the microbon (9) placed near the end of the pipe where the sound is generated. Object (1
) and the limb canal (2) changes, the sound frequency, sound pressure level, and noise level change, so the distance can be determined by fixing the sound frequency, sound pressure level, or noise level M1.

As an embodiment of the present invention based on the above-mentioned principle, the displacement between the table and the spindle head due to thermal deformation of a high-precision machine tool is continuously measured and the amount of displacement is immediately corrected to enable high-precision machining. It is also used as a sensor for accurately detecting the proximity of assembled parts to the main body in automatic quaternary assembly machines. Furthermore, the present invention has a wide practical range, such as being used as a method for accurately determining the amount of expansion of a material when the coefficient of linear expansion of the material is 811. Tube length 40mm,
When the inner diameter of the tube is 2 mm and air with a pressure of 2 Pa is blown into the open end of the tube, the distance between the limb and the object is 3050 Hz at 100 cm, and 2650 at 50 CIL/.
Hz, the frequency of the sound changes to 2210 Hz in a '252 chronograph.

By determining the frequency, sound pressure level, or noise level of the sound effect of the invention, it is possible to accurately determine the distance in units of 7 microns, and it is also easy to measure even when the distance changes continuously. In addition, even if the object (1) is rotating, it is possible to determine the distance without contact. Furthermore, since the sound generated is a sound with a specific frequency determined by the pipe dimensions, air pressure, and the angle between the nozzle and the end of the pipe, it can be used even in places with background noise such as factories.
In addition to requiring no skill for measurement, the (1) II measurement device is simple, requires low equipment and operating costs, and has many practical effects such as being able to perform measurements quickly and accurately.

[Brief explanation of drawings]

Figure 1 is an 11th view, Figure 2 is a perspective view.

Claims (1)

[Claims] Blowing air into the open end of a thin tube or a hole in the outer circumference generates sound, and brings the object to be measured close to the other end of the tube or another hole in the outer circumference to change the distance between the two. By inserting a rod into the inner surface of the tube from the other end and changing the position of the rod, the frequency, sound pressure level, and noise level of the generated sound change. This relates to a method for determining 1tll of the N method.