JPS6230905A - Measuring device for between-gauge-mark distance deviation of test piece - Google Patents

Abstract

PURPOSE:To effect accurate optical measurement, by collecting laser beam reflected from both gauge marks of a test piece and calculating a between- gauge-mark distance from the number of pulses corresponding to the positions of the marks. CONSTITUTION:A synchronous pulse generator 3 generators a pulse with the specified period and supplies the pulse to laser driving unit 4 and pulse reader 8. A luminous unit 5, in synchronization with this pulse, emits laser beam 2 successively parallel with the specified distance. Onto top and bottom gauge marks A, B of the test piece 2, reflecting tapes 10, 10' are applied to reflect the possible incident laser beams on these tapes. A light-collecting unit 6 collects laser beams reflected from the tapes 10, 10' and the collected reflected beams are detected by a sensor 7. At a pulse reader 8, the reflected beams from the tapes 10, 10' are checked for the order of the luminous lamps that emitted this reflected beam. An output unit 9 obtains the number of pulses contained between the taped 10, 10' from the tapes that have been read out and an output is issued for a between-gauge-mark distance from the obtained number of pulses and distance of light emission.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to gauge-to-gage displacement of a test piece in material testing:
Concerning a measuring device.

(Prior art) Measurement of gage elongation of a test piece in a tensile test has conventionally been carried out using
The test was carried out by attaching an extensometer directly to the gauge point of the test piece.

(Problems to be Solved by the Invention) However, with the type of extensometer that is directly attached to the test piece described in -, it is troublesome to actually attach it to the test piece, and if the attachment is in poor condition, the extensometer and test In addition to the problem that slippage occurs between the test piece and the gage, making accurate measurements impossible, there is also the problem that the extensometer is ejected and damaged when the test piece breaks.

(Means for Solving the Problems) In order to solve the above problems, the present invention has the following configuration.

That is, the gauge-to-gage displacement measuring device according to the present invention includes a pulse generator that generates a predetermined synchronizing pulse, and a pulse generator that sequentially synchronizes with the pulses of the pulse generator from one end to the other end in a predetermined light emitting range. a light-emitting part that emits laser beams in parallel toward the test piece at predetermined intervals; a light-concentrating part that collects the laser beam from the test piece; A pulse reading section reads which pulse the laser beam reflected or blocked by the frame point corresponds to, and the number of pulses between the two frame points is calculated based on the reading result of the pulse reading section. It is equipped with an output section that calculates and outputs the gauge distance of the test piece from the number of pulses and the emission interval.

(Function) In synchronization with the pulses from the synchronous pulse generator, the light emitting section sequentially emits a powerful laser beam toward the test piece from one end of a predetermined light emitting range to the other end.

This laser beam passes through the test piece and reaches the condensing part.
The pulses of light that are reflected or blocked by the reference points on the specimen are read. Then, the gauge distance is calculated from the number of pulses included between the pulses corresponding to both frame points and the emission interval.

(Example) Below, the example shown in the drawings will be explained.
FIG. 1 is an explanatory diagram of the configuration of the present invention, and this gauge-to-gauge displacement measuring device 1 is used at a position away from a test piece 2 attached to a material testing machine, and a synchronous pulse generator 3
, a laser drive section 4, a light emitting section 5, a light condensing section 6, a sensor 7, a pulse reader 8, and an output section 9.

The synchronous pulse generator 3 generates a high frequency (several KH) at a predetermined period.
This is a device that generates pulses (appropriately 2 to several MH2), and supplies these pulses to the laser drive unit 4 and pulse reader 8. The light emitting part 5 is 1. Pulse generator 3
This is a part that sequentially emits laser beams in parallel within a predetermined light emitting range (W) in synchronization with pulses from the test moon, and the light emitting range is wider than the gauge distance of the test moon. The light emitting unit 5 in the illustrated example has n light emitting lamps arranged in 14 circles at equal intervals, and as shown in FIG. 2, from one end (Ll) to the other end (Ln). Light is emitted while shifting the light emitting position one by one for each pulse.

Test month 2 1- Reflective tape 10 at lower gauge positions A and B
．． 10' is pasted H, and the laser beam emitted from the light emitting part 5 hits this reflective tape 10.10' and is reflected. Other parts of the specimen are not covered with reflective tape and do not reflect the laser beam.

The condensing unit 6 is a condensing lens 6 that condenses the laser beam reflected from the reflective tape 10.10' of test J4'2.
a, and the reflected light collected by the condenser lens is detected by the sensor 7.

The pulse reader 8 is a device that reads which pulse the reflected light detected by the sensor 7 corresponds to, and is a device that reads reflective tape 10.10 attached to the upper and lower gauge points -L.
The number of the light emitting lamp that the reflected light from ' is from is read here.

The output unit 9 calculates the number of pulses included between the reflective tape 10 and 10' of ): 7' from the pulses read by the pulse reader 8, and calculates the number of pulses and the emission interval (
This is the part that calculates and outputs the gauge distance from the distance #) between two adjacent f-row laser beams. Assuming that the number of pulses between gauges before the start of loading is Pk, the number of pulses between gauges after a predetermined load is PM, and the emission interval is d, the displacement between gauges 6 sentences is Δ sentence = (Pi-Pk)Xd Hail to you.

Note that the light emitting unit 5 may be of any type as long as it can emit a laser beam in a straight line by shifting its position at equal intervals for each pulse, and instead of the one shown in FIG. It is also possible to employ a device as shown in the figure. That is, the one shown in FIG. 3 has one light emitting body 11, a rotating polyhedron 12, and a projection lens 13 instead of arranging a plurality of light emitting lamps in parallel. The laser beam is reflected by the rotating polyhedron 12 toward the projection lens 13, and is projected from the projection lens 13 in parallel toward the test piece 2. Since the angle of the reflecting surface changes as the rotating polyhedron 12 rotates, the light projection position moves regularly at predetermined intervals for each pulse.

What is shown in FIG. 4 is the rotating polyhedron 1 of the device shown in FIG.
It has Culper 14 instead of Galber 1.
4, the light projection position from the light projection lens 13 moves regularly at predetermined intervals.

The one shown in FIG. 5 is one in which an acoustic grating lens 15 is provided in place of the -I- rotary polyhedron 12 and the galver 14.
By changing the diffraction angle by the acoustic grating lens, the position of the light projected from the light projecting lens 13 is moved regularly at predetermined intervals.

In the following embodiments, the laser beam reflected from the gauge point of the test piece 2 is focused to obtain a pulse corresponding to the position of the gauge point. The test piece 2 is placed on the opposite side from the light emitting part 5, and a light shielding body such as a protrusion is attached to the gauge point of the test piece 2 to block the laser beam from the light emitting part 5. It is also possible to configure the light beam to transmit the light beam, and to obtain the gauge distance from the pulse of the blocked light beam.

(Effects of the Invention) As is clear from the above explanation, the gage snack number 1 measuring device according to the present invention is capable of optically performing high-precision measurement using a laser beam, and is Since there is no need to attach a sensor or the like directly to the test piece as in the case of a meter, there is no need for complicated removal work, and there is no risk of damage when the test piece breaks.

[Brief explanation of the drawing]

FIG. 1 is a configuration explanatory diagram showing an example of the gauge-to-gauge displacement measuring device according to the present invention, and FIG. 2 is a graph showing pulses.
FIGS. 3 to 5 are explanatory diagrams of the configuration of the light emitting section according to different embodiments. l... Gauge displacement measuring device 2... Test piece 3
... Pulse generator 5 ... Light emitting section 6 ... Focusing section 8 ... Pulse reader 9 ... Output section
Applicant Shimadzu Corporation Representative Patent Attorney Hiroshi Sugawara Figure 2 Figure 5

Claims (1)

[Claims] (1) A pulse generator that generates a predetermined synchronization pulse;
a light emitting unit that emits a laser beam in parallel toward the test piece from one end to the other end in a predetermined light emitting range at predetermined intervals in synchronization with the pulses of the pulse generator;
A condenser unit that condenses the laser beam from the test piece, and which pulse corresponds to the laser beam reflected or blocked by both gage points of the test piece from the laser beam condensed by the condenser unit. A pulse reading section that reads the pulse reading section, and an output that calculates the number of pulses between both gauges based on the reading results of the pulse reading section, calculates the distance between the gauges of the test piece from the obtained number of pulses and the emission interval, and outputs the result. A gauge-to-gage displacement measuring device for a specimen, comprising: