JPS59203904A - Contactless measuring method of sectional size - Google Patents

Abstract

PURPOSE:To measure sectional size without damaging the surface of a linear body in irregular torsional motion nor deforming the body by irradiating the body with laser light beams which oscillates crossing the linear body in >=3 directions. CONSTITUTION:Wire diameter measurement systems S1-S3 which utilize three laser light beams are arranged at equal intervals of 120 deg. on a circumference C which includes the linear body W having rectangular section in the center. Those measurement systems S1-S2 each have a laser light source 1, reflection mirror 3, rotating mirror 5 which oscillates a laser beam across the linear body W at a frequency of hundreds of Hz, and lens 7 which shapes this laser beam into a parallel beam. This constitution measures the sectional size without deforming the body.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a measurement method for instantaneously determining the cross-sectional dimension of a linear object having a rectangular cross section that undergoes irregular twisting motion without contact.

Conventionally, methods for measuring the cross-sectional dimensions of an object with a rectangular cross section that undergoes irregular twisting motion, such as an optical fiber tape core that undergoes twisting and rotation during the drawing process, involve stopping the irregular twisting motion. The method used was to change the irregular twisting motion to regular twisting motion and calculate the dimensions from the maximum and minimum values detected using a non-contact outer diameter measuring device, thickness measuring device, etc. .

However, in the above conventional methods, it is necessary to apply an external force to the object in order to stop the irregular twisting motion or change the irregular motion into regular motion, which may cause scratches on the object surface. There is a risk of deforming or damaging the object.

The present invention eliminates the above-mentioned conventional drawbacks, and provides a method for measuring the cross-sectional dimension of a linear object having a rectangular cross section that undergoes irregular twisting motion in a completely non-contact state while the irregular twisting motion continues. The purpose is to provide

Therefore, the present invention irradiates a linear object with a rectangular cross section that makes irregular twisting motions with a laser beam that vibrates in a direction across the linear object from three or more directions, and detects the oblique shadow with a photoelectric element. By processing the detection signal with a computer, the cross-sectional dimensions of a door-like object can be determined instantly without contact, and the cross-sectional dimensions can be determined without the risk of damaging the surface of the object or deforming or damaging the object. It is characterized by being able to measure.

Hereinafter, the content of the present invention will be explained in detail with reference to the accompanying drawings.

As shown in FIG. 1, in the method of the present invention, a linear object W having a rectangular cross section is
Three sets of wire diameter measuring systems S□, S2, and S3 using laser light are arranged at equal intervals.

As shown in the figure, each measurement system S, S2, and S3 includes a laser light source 1, a reflection mirror 3, and a rotating mirror ( or a tuning fork deflector) 5, a lens 7 for forming the laser beam into a parallel beam, and a condenser lens 9 disposed at a point symmetrical position with the lens γ with the linear object W in between.
A photoelectric element 11 that receives light from the condensing lens 9 is included.

When the object W to be measured is scanned by a laser beam vibrating at several hundred Hz formed by each measurement system S□, S2, and S3, the scanning light is focused by a condensing lens 9 and received by a photoelectric element 11. , a rectangular waveform signal representing the shadow of the object W, that is, an output waveform signal in which the light intensity falls in the shadow part of the object W, is obtained, and from this, the diagonal shadow size of the object W can be accurately determined. Since the measurement systems S, S3, and S3 are used in three sets separated by 120 degrees, signals representing the oblique shadow dimensions of the object W from three directions separated by 120 degrees are obtained, and these signals are used for calculations by a microcomputer, etc. It is possible to calculate the cross-sectional dimensions of an object through arithmetic processing using a device. An example of the calculation method will be explained with reference to FIG. 2. If the oblique shadow dimensions obtained from the received signal of the light-receiving confectionery 11 are a, b, and c, then from FIG. 2, the following equation holds: 0 r a = L cos (α-β 10 stones) b= L cos (α+β) π C= L cos (“β-100) (L: Diagonal length of the object to be measured, α: Torsion angle of the object to be measured with respect to the reference direction , β: angle between the long side of the object to be measured and the diagonal) From this, the cross-sectional dimensions L sin β and L cos β of the object are determined as follows.

L sin β = Asin(%cos'(:)-%co
s”(i)4) −・■Lcosβ=:Acos(
%cos-1(N)””””. 8-1(i)4) −
= ■ To perform this arithmetic processing, an analog signal from the photoelectric element 11 representing the oblique shadow dimension of the object to be measured is A/D converted and inputted to a microcomputer, and a program is run to calculate L sin β and L cos β from the above equation. If executed, the calculation process can be completed in millisecond order. The measurement accuracy by this method is determined by the determinism of the laser beam, the accuracy of the light receiving element, etc., but if a highly accurate one is used, it is possible to obtain an accuracy of several μm or less. In addition, it is necessary to configure the measurement system so that it can detect the irregular torsional motion of the object to be measured at a sufficiently high detection speed. If the deviation is about 3 rad/sec, it can be measured with sufficient accuracy by using a laser beam with a scanning speed of about 100 to 1000 Hz/sec. By the above method, it is possible to highly accurately measure the cross-sectional dimension of a linear object having a rectangular cross section that undergoes irregular twisting motion in a completely non-contact manner while the object undergoes irregular twisting motion.

In addition, in the above embodiment, especially the wire diameter measuring systems S□, S3
, S3 are arranged at equal intervals of 120° around the object to be measured W, but the present invention uses three or more sets of the wire diameter measurement systems described above, and the angular arrangement is non-equally spaced. The cross-sectional dimensions of objects can be measured. Further, the calculation equation for determining the cross-sectional dimension is not limited to the above equation.

(Example) An example of the present invention is shown below.

As shown in Fig. 1, a plastic tape with a rectangular cross section is placed on each wire diameter measuring system S, S2 at equal intervals of 120° on a circumference of 500 around the center of the cross section of the tape. , S3, the parallel beam forming lens 7 and the condensing lens 9 are arranged facing each other, and the laser light source 1 is He-Ne.
A laser, a tuning fork deflector as a vibration beam forming means, and a microcomputer as a calculation unit are prepared, and the laser beam is transmitted through the object to be measured as a parallel vibration beam of 500 Hz by the tuning fork deflector and lens, and the laser beam is transmitted by a photoelectric element. When the received light signal was processed by a microcomputer according to the above calculation formulas (1) and (2), values of 52 μm in length and 349 μm in width were obtained. When the cross-sectional dimensions of this tape were measured using a microscope, values of 50 μm in length and 351 μm were obtained.

As described above, according to the present invention, the cross-sectional dimensions of a linear object having a rectangular cross section that undergoes irregular twisting motion can be measured without applying any external force to the linear object. Since measurements can be made while the object is still in place, it is possible to measure the cross-sectional dimension without scratching the narrow surface of the object or deforming or damaging the object, unlike conventional methods.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle of the method of the present invention, and FIG. 2 is a diagram showing the relationship between a linear object and a diagonal shadow dimension. 1... Laser light source, 5... Rotating mirror, 11... Light receiving element, W-... Linear object, S work, S3, S3... Measurement system. Patent applicant: Sumitomo Electric Industries, Ltd. (4 others) Figure 1 Figure 2

Claims (1)

[Claims] A linear object with a rectangular cross section that makes irregular twisting motions is irradiated with laser light that oscillates in a direction across the linear object from three or more directions, the oblique shadow of the object is detected by a photoelectric element, and the detection signal is sent to a computing unit. A measurement method that instantaneously determines the cross-sectional dimensions of linear objects without contact.