JPS6149612B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a creep test device that scans a sample using a scanning device such as a television camera and measures the elongation or contraction of the sample at a predetermined time based on the output signal of the scanning device. In the creep test, which measures the elongation of a sample of fiber, rubber, resin, etc. when a certain load is applied to it, or the shrinkage of the sample after the certain load is removed, the load is applied while holding both ends of the sample. In addition, as the amount of deformation of the sample increases, the sample slips from the gripping means, so measuring the distance between the gripping means does not mean measuring the actual elongation or contraction of the sample. For this reason, in the past, a pair of marked lines were attached to two locations on the sample, and the area between the marked lines was regarded as the length area to be measured, and the distance between the marked lines (the length of the measured length area) was determined by the measurer using a scale, etc. The commonly used method is to measure with the naked eye. However, because this method performs measurements manually, it has the disadvantage that the measurement results vary widely even when the same person measures it, and it lacks reproducibility.Furthermore, the measurement results vary depending on the person taking the measurements. Furthermore, if the sample is being measured inside a thermostatic chamber, even if a scale is installed inside the chamber, the variation in measurement results will become even greater. In addition, it is physically impossible to perform measurements over short periods of time, such as immediately after a load is applied or immediately after the load is removed, when the sample expands or contracts rapidly. It is inefficient to keep the measurer restrained for a long time for long-term measurements. Normally, creep tests involve measuring multiple samples at once, but in this case it is impossible to measure using a scale, and in creep tests for minute deformations such as metals, dial gauges are used. It is necessary to use a differential transformer or to take measures to prevent the sample from slipping out of the gripping part (Japanese Patent Application Laid-open No. 50-8583, JP-A-55
−10573). For samples that undergo large deformations such as rubber, a method has been used in which a ring sample is used and the distance of the gripping means is set as the elongation of the sample. However, with this method, creep failure occurs from the gripping part, resulting in true sample failure. In many cases, accurate measurement results cannot be obtained, and creep recovery after load removal cannot be measured. In order to eliminate such drawbacks, it is conceivable to measure the elongation and contraction of the sample by measuring the length between the gauge lines using a surface scanning device such as a television camera. However, in the case of a sample that stretches 5 to 10 times before breaking, such as rubber, the field of view of the scanning device must be set in advance to at least 5 to 10 times the distance between the gauge lines when no load is applied. Therefore, the clamp fitting for gripping the sample and other objects around the sample enter the field of view, making it difficult to distinguish between the signal corresponding to the object in the output signal of the scanning device and the signal corresponding to the marked line on the sample surface. difficult to do. A first object of the present invention is to specify a measurement range within the scanning range of a scanning device, so that even if a foreign object such as a clamp fitting is present within the scanning range,
An object of the present invention is to provide a creep test device that can obtain an electrical signal corresponding to the length of a length-measuring region using an output signal of a scanning device. A second object of the present invention is to provide a creep testing device that can measure both the elongation of a sample after applying a load and the elongation of a sample after removing the load. A third object of the present invention is to provide a creep test device that can accurately measure rapid changes in a sample over a short period of time, when the sample elongates or shrinks most significantly and has conventionally been impossible to measure manually. It is on offer. A fourth object of the present invention is that by using an arithmetic control circuit, it is possible to measure the elongation or contraction of a sample over a long period of time and obtain necessary data such as the viscoelastic coefficient. To provide a creep testing device. A fifth object of the present invention is to reduce creep by making it possible to simultaneously and accurately measure the elongation or contraction of multiple samples by using a surface scanning device that scans two-dimensionally, such as a television camera. To provide testing equipment. When carrying out the present invention, the sample is extended in the vertical direction and a load is applied to the lower end of the sample.The sample extends downward due to the applied load, and upward when the load is removed. Since it shrinks, the direction of expansion and contraction of the sample is in the vertical direction, which is preferable because the scanning device can be fixed. In other words, if the sample is tilted or placed horizontally, removing the load will cause the sample to move out of the scanning range of the sagging scanner, making measurement impossible, so the scanner must be tilted or moved. but,
If the sample is extended in the vertical direction, the position of the sample is the same before and after the load is removed, so there is no need to move the scanning device. A first feature of the present invention is that the scanning range of the scanning device is indicated by indicating a signal to be used as length data in the output signal of the scanning device, and the clamp fitting is placed within the scanning range. It is possible to accurately extract a signal corresponding to the length-measuring area even if objects such as the above are present. In other words, the amount of elongation, the rate of elongation, the amount of shrinkage, and the rate of shrinkage of a sample in a creep test are not necessarily constant depending on the characteristics of the sample, the load, and the test temperature, so when using a scanning device, the scanning range should be widened. If the scanning range is wide, an object such as a clamp fitting with a surface similar to the marking line (or optical characteristics) on the sample will be included in the scanning range, and the output signal of the scanning device will correspond to the object. It is difficult to distinguish between the signal corresponding to the marked line and the signal corresponding to the marked line. Therefore, in the present invention, a measurement range instruction signal is generated electrically or mechanically to indicate a signal corresponding to the length measurement area in the output signal of the scanning device, and the measurement range instruction signal is used to indicate the signal corresponding to the length measurement area. Extract the corresponding signal. In this way, it is possible to accurately extract a signal corresponding to the length-measured area, and to obtain accurate length data. The measurement range instruction signal triggers a timer using, for example, a scanning reference signal (scanning reference signal) by a scanning device, and when the timer returns, a flip-flop is set, and when the end of the length measurement area has been scanned, a timer is triggered. This can be generated by clearing the flip-flop and using the set output of the flip-flop as the measurement range indication signal, and triggering the second timer when the timer returns to the output of the second timer. It can be generated by making the signal the measurement range indication signal. In addition, the measurement range instruction signal causes the sample to extend in the vertical direction, moves to follow the change (expansion and contraction) of the sample, and the end edge is connected to the sample gripping part in the direction of change of the sample and the length to be measured. A measurement range guide plate located between the regions can be provided, which guide plate can be scanned together with the sample to generate a signal corresponding to the guide plate in the output signal of the scanning device. The guide plate may be attached directly to the sample, or may be attached to a clamp fitting that grips the sample. When attaching the measurement range guide plates to the upper and lower clamp fittings, in the creep test device, the clamp fittings are removed from the sample by removing the load. out of the scanning range. However, the sample will shrink after the load is removed, and if there is a clamp fitting outside the scanning range of the scanning device, there will be no harm caused by the clamp fitting and there will be no practical problem. Length data may be extracted using the immediately preceding measurement range as the subsequent measurement range. When attaching the measurement range guide plate directly to the sample,
It is only necessary to install measurement range guide plates between the length-measuring area and each clamp fitting, and in this way, both defined range guide plates can be used for measuring both elongation and contraction of the sample. In this case, since the weight of the measurement range guide plate is applied to the sample as a load even after the load is removed, it is preferable to use a light measurement range guide plate. In a creep test, when the load is removed, the sample may turn sideways or twist, and in this case, it is not possible to extract a signal corresponding to the length region to be measured from the output signal of the scanning device. To solve this problem, attach a light weight to the lower end of the sample. Therefore, in the measurement range guide plate, the upper guide plate is fixed to the upper clamp fitting so that its lower end is located between the lower end of the upper clamp fitting and the upper end of the length area to be measured, and the lower guide plate is fixed to the upper end of the measuring range guide plate. It is preferable to attach it directly to the sample so that it is located between the lower end of the length measurement area and the upper end of the lower clamp fitting. When removing a predetermined load after applying a predetermined load to a sample for a predetermined time, the load must be removed from the sample instantaneously. The simplest method for removing the load is for the operator to remove the load from the bottom chuck of the sample, but this method requires the operator to get close to the sample and completely block the field of view of the scanning device. It is not possible to measure the shrinkage of the sample immediately after the load is removed, and if there are only a few pieces of the sample, it is not possible to measure the elongation or shrinkage of other samples. Furthermore, if the sample is inside a thermostatic chamber, it is necessary to open the chamber door and remove the sample and the lower chuck, but this is undesirable as it lowers the temperature of the chamber. There are also devices that use air chucks that tighten the chuck using air pressure, and remove the air pressure to release the chuck's tightening force, and devices that mechanically release the chuck's tightening force from a distance. For samples that deform by a factor of 10, the sample surface and chuck often do not separate easily due to the adhesive nature of the rubber. Therefore, by providing a small door in the tank,
It is most reliable and simple to forcibly cut between the lower end of the length measurement area and the lower chuck with a sharp tool such as a knife or scissors by remote control from outside the field of view of the scanning device. If a light guide plate is wrapped directly around the surface, it is sufficient to cut between the guide plate and the lower chuck. In addition, by wrapping an adhesive tape around the sample surface of the lower chuck and checking the adhesive tape, the lower chuck can be removed by reducing the air pressure in the case of an air chuck or mechanically releasing the clamping force of the chuck. If the load is removed, the chuck can be easily removed, but if the sample is deformed by a factor of 5 to 10, slips may occur between the adhesive tape and the chuck, which is not necessarily preferable. It may be possible to apply paint to the clamp fittings, etc. that have the same optical characteristics as the gauge line on the sample surface or the area to be measured, and to make the clamp fittings, etc. the same color as the background, so that they do not indicate the measurement range. In this case, if creep failure occurs, one of the gripping means will fall and collide with the main body of the device, causing the paint to peel off.Also, if the operator manipulates the gripping means when attaching the sample, the paint will easily peel off. ,
Must be reapplied. A second feature of the present invention is that the lower chuck of the sample and the shrinkage of the sample after the load is removed can be read by a scanning device to obtain the shrinkage rate of the sample along with the elapsed time after the load is removed. The indication of the measurement range after load removal is because there is no longer a bottom chuck or load on the sample, so even at the widest measurement range immediately before load removal, there are no optically anomalous substances in the field of view of the scanning device. It is possible to accurately extract the signal corresponding to the length measurement area. Furthermore, if a light guide plate is directly wrapped around the lower part of the sample, the measurement range may be designated as the area between the guide plate attached to the upper chuck and the guide plate attached to the lower part. A third feature of the present invention is that by using the scanning device, for example, if a television camera is used, a length signal can be extracted at a rate of once every 1/30 sec. It is possible to accurately capture the rapid deformation of the sample immediately after removal, and to extract signals corresponding to the length-measuring region at high frequency. The frequency at which length data is taken can be freely selected depending on the deformation speed of the sample, and since the deformation speed of the sample generally decreases logarithmically with the elapsed time from the start of the test, for example, every 0.05 seconds at the beginning. It is easy to retrieve the length signal every 60 seconds, then every 10 minutes near the end of the test. In this manner, the present invention can extract length data such as elongation or contraction of a sample in a short period of time immediately after load application and immediately after load removal, which was conventionally impossible to measure manually. A fourth feature of the present invention is that it is suitable for creep property testing of flowable solid samples. Fluid solid substances such as unvulcanized rubber are
When a load is applied, it deforms fluidly and causes creep failure. In such a solid material sample, there is no significant change in the rate of deformation from the time a load is applied until creep rupture occurs, and all of these rates are high, which was previously thought to be impossible artificially. The present invention can also effectively measure such samples. The fifth feature of the present invention is that by accurately extracting the length signal of the sample in the creep test, the total test time of the creep test can be automatically measured. Not only does it eliminate the need to restrain the sample, but it also allows viscoelastic analysis of the sample from the measurement results, making it easier and more accurate to analyze the viscoelasticity of large deformations that are 5 to 10 times larger than conventional measurements and analysis that required manual labor. This is something that can be done. The sixth feature of the present invention is that the field of view of surface scanning is divided into equal parts, the expansion or contraction of multiple samples can be simultaneously scanned, and the signals of multiple samples corresponding to the length measurement area can be independently extracted. be. First, the principle of this invention will be explained based on FIGS. 1 and 2. Samples S,
As shown in FIG. 1A, S' has marked lines Q and Q at two locations separated in the longitudinal direction, or has a mark area Q' near the center as shown in FIG. 2A.
The marked lines Q, Q and mark area Q' are obtained as a level difference between the portions corresponding to them and the portions corresponding to other areas on the sample surface in the output signal of the television camera, which will be described later. The optical characteristics such as lightness, brightness, hue, etc. are different from other areas on the sample surface. It can be formed by In the present invention, while pulling the samples S and S' in the longitudinal direction, a known black-and-white television camera or a color television camera (hereinafter simply referred to as a TV camera) used for broadcasting or industrial purposes is used.
The distance L between the gauge lines in the longitudinal direction of the sample and the length L' of the mark area are calculated for each sample based on the signal of the part corresponding to the gauge line or mark area in the output signal. It is something to seek. That is, for example, the marked lines Q, Q or the marked area
If Q' is white and other areas of the sample surface are black, samples S and S' are imaged with a TV camera in a state where the surroundings (background) are black or dark.
If the direction of the scanning line of the TV camera is parallel to the longitudinal direction of the sample, the output signal will be as shown in Figure B for sample S in Figure 1, and as shown in Figure B for sample S' in Figure 2. As shown in B, the portions corresponding to the gauge lines and mark areas are at a higher level than other portions. Therefore, a certain level of the TV camera output signal
By extracting only the signal of V ₁ or more,
Convert to the signal shown in Figure C. The pulse interval T and time width T' of the signal obtained in this way correspond to the scanning time between the marked lines by the TV camera and the scanning time of the mark area, and also correspond to the scanning time of the marked area due to the change in time after the load is applied. It increases or decreases following changes in the distance L and the length L' of the yark area. Therefore, by using the pulse interval T and time width T', the gauge line distance L and the length L' of the mark area can be determined, and thereby the elongation or contraction of the sample can be determined. If the direction of the scanning line of the TV camera is perpendicular to the above-mentioned direction, the output of the TV camera will be
In the case of the sample shown in the figure, the result is as shown in figure D, so the elongation of the sample can be determined in the same manner as described above.
Also, if the optical characteristics are opposite to those described above, the level of the output signal of the TV camera will be opposite to that described above, so after extracting the signal below a certain level, determine the elongation or contraction of the sample in the same manner as described above. be able to. When measuring the elongation or contraction of multiple samples at the same time, attach each sample to the testing machine body so that it falls within the field of view of the same TV camera, scan each sample simultaneously with the TV camera, and record the output signal. It is sufficient to perform discrimination corresponding to each sample, and process each discriminated signal as described above. In the present invention, the area between the marked lines Q and Q and the mark area Q' on the sample surface is referred to as the length-to-be-measured area, and the length of the area to be measured in the longitudinal direction of the sample is referred to as the to-be-measured length. It is called the region length. Also, regardless of the direction of the TV camera's scanning line, the longitudinal direction of the sample is called the vertical direction, and the direction perpendicular to it is called the horizontal direction. The embodiment shown in FIG. 3 will be described below.
This device can handle two samples as shown in Figure 4A.
This is an example of a device that simultaneously measures the elongation or contraction of S′ ₁ and S′ ₂ .
As shown in FIG. 4A, S' ₁ and S' ₂ are upper clamp fittings CM 1 and CM ₁ of the testing machine main body (not shown).
CM ₂ respectively, and the lower portions are separately clamped to the lower clamp fittings CMM ₁ and CMM ₂ of the main body so that the longitudinal direction is the vertical direction, and the lower clamp fittings CMM ₁ ,
Loads W ₁ and W ₂ are applied in the direction in which CMM ₂ moves away from the upper clamp fitting. Also, each sample S′ ₁ ,
S' ₂ has the aforementioned mark areas Q' ₁ and Q' ₂ , respectively. In order to simplify the explanation, this example will be described assuming that each clamp fitting and mark area have high brightness, and the other areas of the sample and their surroundings have low brightness. The apparatus shown in FIG. 3 includes a TV camera 1 that images the field of view M in FIG. A signal discriminator 3 which is taken out separately, a signal processing circuit 4 which generates length data corresponding to the distance between gauge lines L for each sample using the output signal of the signal discriminator 3, and a length which is input from the signal processing circuit 4. The data processing circuit 5 captures and stores data at predetermined time intervals. The TV camera 1 is installed in front of each sample so that the longitudinal direction of the samples S' ₁ and S' ₂ is perpendicular to the direction of the scanning line. An image is taken within the field of view M in Figure A. The reference signal generator 2 generates the drive signal KC.
In addition, a line scanning reference signal KL, a surface scanning reference signal KF shown in FIG. 4C, and a surface scanning end signal EF are generated and supplied to the signal discriminator 3, respectively. The signal discriminator 3 includes monostable multivibrators MA, MB, M ₁ , M ₂ , flip-flops FF ₁ , FF ₁₂ , FF ₂₁ , FF ₂₂ , and an AND gate.
AND ₁ , AND ₂ , inverters INV ₁ , INV ₂ , and waveform converter WP. The waveform converter WP is
This is a waveform shaping circuit that converts the output signal of the TV camera 1 into a digital signal, and its output is a thin pulse-like signal. This output signal is an AND gate
Fed into one input of AND ₁ and AND ₂ . Monostable multivibrator MA and M ₁ , MB and
_M2 are connected in series in a one-to-one pair, and the multivibrators MA,
MB is determined from the line scanning reference signal KL shown in FIG. 4K.
The signals delayed by the times TA and TB in FIG. 4 are generated, and the subsequent multivibrators M ₁ and M ₂ are
Signals L and M in FIG. 4 having widths of times T ₁ and T ₂ in FIG. 4, respectively, are generated and supplied to AND gates AND ₁ and AND _2, respectively. Each output signal corresponds to zones Z 1 and Z ₂ that respectively contain samples S' _{1 and} S' ₂ with respect to the field of view M of the TV camera 1, as shown in FIGS. 4A, L, and M. Therefore, among the output signals of TV camera 1, the multivibrator
The output signal of M ₁ is supplied to zone Z ₁ , and the output signal of M ₂ is supplied to corresponding AND gates AND ₁ and AND ₂ as a gate signal, that is, a horizontal measurement range indication signal, for extracting the signal corresponding to zone Z ₂ . Ru. The multivibrator MC generates a signal delayed by a fixed time TC from the surface scanning reference signal KF shown in FIG _.
Set FF ₂₁ . Flip-flop FF ₁₁ is cleared by the output signal of flip-flop FF ₁₂ as described later, and the output signal is cleared by the _fourth
It is supplied to the AND gate _AND1 as the longitudinal measurement range indication signal shown in FIG. Similarly, flip-flop FF ₂₁ is cleared by the output signal of flip-flop FF ₂₂ , which output signal is applied to AND gate AND ₂ as the longitudinal measurement range indication signal shown in FIG. 4J for sample S' ₂ . multi vibrator
In this example, it is assumed that the upper clamp fittings CM ₁ and CM ₂ are fixed, so the delay time TC of MC is determined at the starting points (rising points) of the signals shown in _{FIG .} The setting time may be set so that it is between the lower end of the upper clamp fitting and the upper end of the length measurement area of the sample during the scanning time of the TV camera 1. The vertical measurement range indication signal is not a signal delayed by a fixed time TC from the surface scanning reference signal KF mentioned above, but is generated using a guide plate attached to the upper clamp fitting, taking into consideration the shrinkage of the sample after the load is removed. Alternatively, the lower end of the upper clamp fitting may be used as the starting point of the signal shown in FIG. 4D. The end of the longitudinal measurement range instruction signal may be created using a signal corresponding to the lower edge of the length measurement area, but since the deformation speed differs depending on the sample, When the measurement range is determined, the lower clamp fitting of an adjacent sample may fall within the range and become impossible to measure. In this case, each sample may have independent longitudinal measurement range zones ZV ₁ and ZV ₂ . For the termination signal of each zone ZV ₁ and ZV ₂ , in addition to the signal corresponding to the lower edge of the length measurement area, a guide plate attached to the lower clamp fitting may be used. A light guide plate wrapped directly around the bottom of the sample may also be used. AND gates AND ₁ and AND ₂ gate the output signal of the waveform converter WP by the output signal of the corresponding flip-flop FF ₁₁ and FF ₂₁ and the output signal of the reacting multivibrator M ₁ and M ₂ , respectively. Length measurement area signals as shown in Figures N and O are generated. That is, according to the horizontal measurement range instruction signal and the vertical measurement range instruction signal, the AND gate AND ₁ of the output signal of the waveform converter WP is set to zone Z ₁ .
and ZV ₁ , and the AND gate AND ₂ gates the signals corresponding to zones Z ₂ and ZV ₂ . Therefore, each and gate
The measured length area signals obtained separately from the outputs of AND ₁ and AND ₂ correspond to each sample, and
Noise components due to clamp fittings, etc. are removed, and the number of pulses corresponds to the length L' ₁ of the mark area on the sample, that is, the length of the area to be measured. The signal processing circuit 4 includes retrigger type monostable multivibrators RMM ₁ and RMM ₂ ,
And gate and ₁ , and ₂ and counter CTR ₁ ,
The output terminals of the oscillator OSC, which generates a clock signal with a constant period, are connected in series to form a set of CTR ₂ , and the output terminals of the oscillator OSC, which generates a clock signal with a constant period, are
Connected to and ₁ and and ₂ . The multivibrators RMM ₁ and RMM ₂ have a time constant slightly longer than the line scanning period of the TV camera 1, and the output signals of the AND gates AND ₁ and AND ₂ are respectively input thereto. Therefore, based on the fact that the density of the scanning lines on the samples S' ₁ and S' ₂ is finer than that of the mark areas Q ₁ and Q ₂ , the input signal is divided into a plurality of pulses as shown in FIG. 4 N and O. Even if it becomes a signal, it becomes one pulse signal as shown in FIG. 4E and F by each multivibrator RMM ₁ and RMM ₂ . each and gate
Since the clock signal generated by the oscillator OSC is input to the other terminal of and ₁ and _{and 2} , this clock signal is input to the corresponding multivibrator RMM ₁ ,
It is gated by the input signal from RMM ₂ and supplied to the corresponding counters CTR ₁ and CTR ₂ . The period of the clock signal is, for example, the line scanning reference signal mentioned above.
You can use KL. In this case, the outputs of the AND gates and ₁ and and ₂ are as shown in FIG. 4 N and O. Each counter CTR ₁ and CTR ₂ counts the input signal from the corresponding AND gate, and the counted value is sent to the data processing circuit 5 every time the TV camera 1 scans the surface.
It is reset by . The data processing circuit 5 is equipped with arithmetic functions and control functions like a microcomputer, and inputs the length data obtained from the counters CTR ₁ and CTR ₂ at predetermined time intervals during the vertical retrace period of the TV camera 1. Capture and store in memory. The length data acquisition cycle is set to 0 when a load is applied and when the load is removed, for example, every 0.1 seconds between 0 and 5 seconds, every 1.0 seconds between 5 and 15 seconds, and every 15 to 15 seconds. You can set it to every 15.0 seconds for 60 seconds, every 1.0 minutes from 1 to 10 minutes, and arbitrarily after 10 minutes. The device shown in Fig. 3 is a monostable multivibrator with a surface scanning reference signal KF shown in Fig. 4C.
Trigger MC to generate the signal shown in Figure 4D that rises after time TC, set flip-flops FF ₁ and FF ₂ with this signal, and feed their outputs to AND gates AND ₁ and AND ₂ individually. . Then, in the AND gates AND ₁ and AND ₂ , the lateral measurement range indication signals inputted from the corresponding multivibrators M ₁ and M ₂ and the corresponding flip-flop
Gating the output signal of the waveform converter WP (see Figure 4B) with the input signals from FF ₁₁ and FF ₂₁ ,
Connect each output signal to multivibrator RMM ₁ , RMM ₂
supply to. Each multivibrator RMM ₁ ,
Since _the measured region length signals shown in _{FIG .}
The output signal is converted into the signals shown in FIG. G and H, and flip-flops FF ₁₂ and FF ₂₂ are set individually at the rising edge of the output signal. Then, the corresponding flip-flop FF ₁₁ receives the output signals of flip-flop FF ₁₂ and FF ₂₂ .
and FF ₂₁ individually and prohibit future sets. Therefore, the outputs of flip-flops FF ₁₁ and FF ₂₁ have a certain period of time from the start of surface scanning of TV camera 1.
The signals shown in FIG. 4, I and J, which rise after TC and fall at the fall of the measured region length signal are obtained, and these signals serve as the longitudinal direction measurement range indication signal. The flip-flops FF ₁₂ and FF ₂₂ are cleared each time a surface scan is performed by a surface scan end signal EF. In addition, if the sample has a marked line, use the multivibrator RMM ₁ ,
A T-type flip-flop may be provided after RMM ₂ , and the output signal of this flip-flop may be supplied to inverters _INV1 , _INV2 and AND gates _and1 , _and2 . In this device, since the end of the length signal of the length to be measured area is the end of the length signal of the longitudinal direction measurement range, the length of the length to be measured corresponding to the mark area (or gauge line) scanned by the longitudinal direction measurement range instruction signal is It falls at the end of the length signal, so even if the length-measuring regions of the samples are different in length, the length-measuring region signals can be reliably extracted for each of the samples. This device uses a TV camera 1 to scan a field of view M, and gates signals corresponding to zones Z ₁ and ZV ₁ and Z ₂ and ZV ₂ within the field of view M with AND gates AND ₁ and AND _2, respectively. Take out each gate separately
The signals shown in FIG. 4E and F can be obtained from the outputs of AND ₁ and AND _2, respectively, and each output signal corresponds to each sample S' ₁ and S' ₂ , respectively, and each counter CTR ₁ , CTR ₂ , the count values obtained each time the TV camera 1 scans the surface correspond to the samples S' ₁ and S' ₂ , respectively, and correspond to the length of the measured length region of the corresponding sample. Therefore, if the counted value of each counter is recorded, memorized, and displayed for each sample (for each counter) in an arbitrary device every time the TV camera 1 scans the surface, it is possible to record, store, and display the counted value of each counter for each sample (for each counter). The length of the region to be measured, which changes from moment to moment, can be obtained for each sample by using the number of clock pulses as the TV camera scans the surface. Further, since the counted values of each counter CTR ₁ and CTR ₂ are usually obtained in the form of a Biley code or BCD code signal, each counted value is supplied to the data processing circuit 5 as length data of the length region to be measured, and the circuit In step 5, the length data can be stored in a memory at predetermined time intervals. As mentioned above, according to this device, the length L′ of the mark area, which changes from time to time after applying a load, can be
Since the count values of the counters CTR ₁ and CTR ₂ can be obtained simultaneously and separately each time the TV camera scans the surface, the elongation of a plurality of samples can be measured individually at the same time. In addition, since the output signal of the TV camera 1 is gated separately in the signal discriminator 3 using each lateral measurement range instruction signal and the signal corresponding to the sample is extracted, the signal corresponding to the sample can be accurately extracted for each sample. . Furthermore, the signal discriminator 3 gates the output signal of the TV camera 1 using the vertical measurement range instruction signal to extract a signal corresponding to the sample, so the signal component corresponding to the clamp fitting etc. is removed and Only the signals within the direction measurement range are available, so the length measurement area signal can be accurately extracted, and as a result, accurate measurement can be performed. In particular, as in this example, if the time width of the longitudinal measurement range instruction signal is made to increase in accordance with the elongation of the sample, even if the sample is made of rubber or the like which has a large amount of deformation under load, clamp fittings etc. It is possible to always remove unnecessary signal components corresponding to . In the above embodiment, the data processing circuit 5 stores the count values of the counters CTR ₁ and CTR ₂ in the memory at predetermined time intervals, but the actual length, that is, the length of the mark area or the actual amount of deformation It may be stored in memory after being converted into , or it may be recorded on recording paper instead of being stored in memory. To actually convert the count value of each counter into a length, for example, proportional conversion may be performed from the count value of each counter in the state before the load is applied. However, to make it simpler, the frequency of the clock pulse can be selected so that the counted value becomes the actual length, for example, when the measured length region is 20 mm, the counted value becomes 20. It is sufficient to make the relationship one-to-one. As a signal for knowing the length of the region to be measured, not only the count value of the counter but also the length signal of the region to be measured itself, that is, the fourth
The signals shown in Figures E and F can also be used. In the embodiment described above, the counters CTR ₁ ,
Once the length data of the measured length area obtained by CTR ₂ is corrected to the proportional value to the actual length,
The true length can then be obtained by multiplying by the proportionality constant. Also, as shown in Figure 5,
A certain length within the field of view M of TV camera 1, for example 100
A reference plate KB with a length of mm is installed parallel to the sample S′, and this zone Z ₀ is defined as a zone Z ₀ that includes this reference plate KB.
The signal corresponding to the length of the reference plate KB is extracted from the output signal of the TV camera 1, and the length data of the area to be measured is proportionally calculated using the reference plate length data corresponding to the length of the reference plate KB as a reference, and the true length of the area to be measured is determined. You can also ask for In this way, even if the characteristics of the TV camera change over time or the distance between the TV camera and the sample changes, measurement can be performed without causing measurement errors. If the length of the region to be measured, which is the most important data in the creep test, is obtained as described above,

[Table] The length data extracted as above is obtained by processing the cross-sectional area of the sample, the load applied to the sample, the time after the start of the test, etc. using calculation processing means such as a microcomputer, and various types of data that could not be obtained conventionally. Viscoelastic data can be obtained automatically. An example of the calculation is shown below. t: Test time (time elapsed from the start of the test to the time of sampling) W: Load ε: Rate of elongation or contraction of the sample σ ₀ = W/A ₀ : Stress on the sample A ₀ : Cross-sectional area of the sample

[Table] Figure 6 shows a device in which a measurement range guide plate is provided on the clamp fitting and a signal corresponding to the guide plate is used to generate a vertical measurement range instruction signal from among the output signals of the TV camera 1. This is an embodiment of the present invention, in which the elongation or shrinkage of a plurality of samples can be measured at the same time. In this example, as shown in _{FIG .}
Similar guide plates MP ₁₁ , MP ₁₂ , MP ₂₁ , MP ₂₂ , while MP ₁₁ and MP ₂₁ have their lower edges connected to the upper clamping fittings.
Lower edges of CM ₁ and CM ₂ and mark areas of samples S′ ₁ and S′ ₂
Located between the upper ends of Q′ ₁ and Q′ ₂ , on the other hand MP ₁₂ and MP ₂₂
are the lower edges of the mark areas Q′ ₁ and Q′ ₂ and the lower clamp metal fittings.
Located between the upper ends of CMM ₁ and CMM ₂ , guide plates MP ₁₁ and MP ₁₂ are both located in longitudinal zone Z ₃ , and guide plates MP ₂₁ and MP ₂₂ are both located in longitudinal zone Z ₄ .
The clamp fittings CM ₁ ,
It is attached to CM ₂ , CMM ₁ , and CMM ₂ . and,
The apparatus shown in FIG. 6 includes a pair of one-shot multivibrators MD ₁ and M ₃₁ and MD ₂ and M ₃₂ , two-input AND gates AND ₃₁ and AND ₃₂ , retrigger type one-shot multivibrators RMM ₃₁ and RMM ₃₂ , Inverters INV ₃₁ , INV ₃₂ , trigger flip-flops TFF ₁₁ and TFF ₁₂ , TFF ₂₁ and TFF ₂₂ pairs,
And two-input AND gates AND ₄₁ and AND ₄₂ are provided for each sample. Multivibrators MD ₁ and MD ₂ individually generate signals delayed by the times TD ₁ and TD ₂ in FIG. 7H and I based on the line scanning reference signal KL shown in FIG _.
and M ₃₂ are triggered by the output signals of the multivibrators MD ₁ and MD ₂ in the previous stage, and individually generate the signals shown in FIG. 7 H and I with the time widths T ₃ and T ₄ in FIG. 7 H and I. and gate AND ₃₁ ,
Supply AND ₃₂ . Multivibrator M ₃₁ ,
The output signal of M ₃₂ is a lateral measurement range indicating signal which individually designates zones Z ₃ and Z ₄ as is apparent from FIGS. 7A, H and I. multi vibrator
MA, MB, M ₁ and M ₂ are the same as the multivibrators MA, MB, M ₁ and M ₂ shown in FIG. 3, so the output signals of the multivibrators M ₁ and M ₂ are as follows:
These are the signals shown in FIG. 7L and M, respectively. The device shown in FIG. 6 is an AND gate AND ₃₁ ,
In AND ₃₂ , the output signal of the waveform converter WP is individually gated by the output of the multivibrators M ₃₁ and M ₃₂ to correspond to the objects in zones Z ₃ and Z ₄ .
A one-shot multivibrator that extracts B ₁ and B ₂ signals individually and retrigger the extracted signals.
Supplied individually to RMM ₃₁ and RMM ₃₂ . These multivibrators RMM ₃₁ and RMM ₃₂ have a time constant slightly longer than the line scanning period of the TV camera 1, and therefore the third
The input signals shown in FIGS. B ₁ and B ₂ are converted into the signals shown in FIG. 7 C ₁ and C ₂ , respectively. Therefore, in this device, this signal is passed through T-type flip-flops TFF ₁₁ ,
TFF ₁₂ is supplied individually to generate the signals shown in Fig. 7 D ₁ and D ₂ , and the inverter is
After INV ₃₁ and INV ₃₂ are individually inverted to the signals shown in Fig. 7 E ₁ and E ₂ , the T-type flip-flop
Figure 7 F ₁ , F ₂ by supplying them individually to TFF ₁₂ and TFF ₂₂
The signals shown in are generated respectively. Then, the output terminals of each flip-flop TFF ₁₁ and TFF ₁₂ are individually connected to the input terminal of a two-input AND gate AND ₄₁ , and the T-type flip-flops TFF ₂₁ and TFF ₂₂ are connected to each other.
Connect the output terminals of each to the input terminals of the two-input AND gate AND ₄₂ separately, and connect the AND gate AND ₄₁ and
The output signal of AND ₄₂ is connected to the AND gate in Figure 3.
Supplied individually to AND ₁ and AND ₂ as longitudinal measurement range indication signals. In this manner, this apparatus can obtain the desired longitudinal measurement range indicating signals for each sample as shown in FIG. 7 _G1 and _G2 at the outputs of the AND gates _AND41 and _AND42 . Note that each T-type flip-flop TFF ₁₁ , TFF ₁₂ , TFF ₂₁ , and TFF ₂₂ is cleared by the surface scanning end signal EF. Next, an example of the data processing circuit 5 shown in FIG. 8 will be described. This circuit 5 includes an arithmetic processing circuit CPU such as a microprocessor, an operation console OPT for inputting various data to the data processing circuit 5, and a memory MER.
It is equipped with five counters CTR ₃ to _{CTR 7} for sample S' ₁ . The operation console OPT has keys for inputting data such as the so-called sampling period n for data acquisition, time N for switching the sampling period, test time Y, etc., a start key for inputting the start of the test, and a key for inputting data such as the sampling period n for data acquisition, the time N for switching the sampling period, and the test time Y, and the start key for inputting the start of the test. A load addition state designation switch that inputs a certain condition, a load removal state designation switch that inputs that the test is after the load has been removed, a CRT display that displays input data, an abnormality alarm that reports an abnormality, and a load removal state designation switch that inputs that the test is after the load is removed. It is equipped with a termination notification switch and the like to notify the termination. The input data such as period n and time N are stored at a predetermined address in the memory MER. Counter CTR ₃ is an address counter that specifies the address that stores the sampling period n, counter CTR ₄ is an address counter that specifies the address that stores the time N, and counter CTR ₅ specifies the address that stores the length data. The specified address counter, counter CTR ₆ , is a counter for counting the elapsed time since the previous sampling.
CTR ₇ is a counter for counting the elapsed time from the start of the test. Each counter CTR ₃ ~ _{CTR 7}
is controlled by the arithmetic processing circuit CPU. Each of the counters CTR ₃ to _{CTR 7} can use a predetermined address in the memory MER. The arithmetic processing circuit CPU stores various data input from the operation console OPT at a predetermined address in the memory MER, and displays it at a predetermined display location on the CRT display.When the start switch is pressed down, the counter CTR ₁ is displayed. , CTR ₂ is stored at a predetermined address in the memory MER at predetermined times. Next, the operation of the arithmetic processing circuit CPU when storing the data of the counter CTR ₁ will be explained with reference to FIG. When the start switch is depressed, the arithmetic processing circuit CPU first clears each counter CTR ₁ to CTR ₇ if the load addition state designation switch is depressed, and clears the counter CTR if the load removal state designation switch is depressed. Clear counters other than ₅ and preset counter CTR ₅ to X. The above X is a value to ensure that the address for storing the data after the load is removed does not overlap with the address for storing the data when the load is added, and the value is, for example, the final address for storing the data when the load is added. It can be a value that specifies the next address. Next, the arithmetic processing circuit
The CPU determines whether or not the length data input from the counter CTR ₁ changes suddenly each time the TV camera 1 scans the surface. Scan end signal
Every time the EF receives an input, it performs data storage processing, and when a predetermined time elapses, it notifies that the test has ended and returns to the standby state. In the storage process, after setting the contents of the address specified by the counter CTR ₃ as the sampling period n and setting the contents of the counter CTR ₄ as the switching time N of the sampling period n, the area scanning end signal EF is input, and the area scanning is started. When the end signal EF is input, 1 is added to the counters CTR ₆ and CTR ₇ , and then it is determined whether the contents of the counter CTR ₆ are equal to or greater than the sampling period n, and if not, the process returns to the above.
or more, the contents of counter CTR ₁ are
Store it together with the contents of CTR ₇ (elapsed time from the start of the test) at the address specified by counter CTR ₅ , clear counters CTR ₁ and CTR ₆ , add 1 to counter CTR ₅ , and then
It is determined whether the contents of CTR ₇ are equal to or longer than the sampling period switching time N. If not, the process returns to the above, and if the contents are equal to or greater, 1 is added to the contents of counters CTR ₃ and CTR ₄ , and then the counter CTR _{7 is} This is done by determining whether or not the content of is longer than the test time Y, and if not, the process returns to the above, and if it is, the end of the test is notified. When storing the data of counter CTR ₂ , the same type of counters as counters CTR ₃ to CTR ₇ are provided in the arithmetic processing circuit CPU, and the length data input from counter CTR ₂ is stored in the arithmetic processing circuit CPU in the same way as described above. It is sufficient to determine whether or not there has been a sudden change every time the TV camera scans the surface, and when a sudden change has occurred, the same data storage process as described above is performed with that time as the test start time. In the above embodiment, the load W, the cross-sectional area of the sample, the initial length of the region to be measured, etc. are also input to the arithmetic processing circuit CPU, and this arithmetic processing circuit calculates the elongation rate of the sample, the stress of the sample, etc. may be calculated. Next, an embodiment of the test machine main body equipped with a load removing device shown in FIGS. 10 and 11 will be described. In the figure, 10a is the upper wall of the thermostatic chamber;
10b is a lower wall. Upper clamp fitting on bottom edge
The support rod 11 having the CM ₁ protrudes through the hole in the upper wall 10a to the upper part of the thermostatic chamber, and is screwed into the support rod 11 with a seat 12 placed on the upper wall 10a above the upper wall 10a. It is supported by a nut 13. Lower clamp fitting CMM ₁ of sample S′ ₁
are attached to the tip portions 21, 21 of the load removing device 20, which is shaped like a washing scoop in this example. A shaft 22, which serves as a fulcrum for opening and closing the load removing device 20, is pivotally attached to the upper end of the weight support rod 14 of the load adding device, and the gripping portions 23, 23 are attached to the lower part of the thermostatic chamber through a hole in the lower wall 10b. It stands out. Load removal device 2
0 is the tip part 21, 2 by the tension coil spring 15.
1, it is fired so as to clamp the lower end of sample _S'1 . The lower end of the weight support rod 14 protrudes below the thermostatic chamber through a hole in the lower wall 10b, and a weight receiving plate 16 on which the weight _W1 is placed is attached to the lower end. The load removing device 20 attaches the lower end of the sample S' ₁ to the coil spring 15 via an anti-adhesive object 17 such as a tape or aluminum wheel attached to the lower end of the sample S' ₁ .
After that, the gripping parts 23, 23
The load is removed by grasping the lower end of the CMM 1 and opening the lower clamp fitting CMM ₁ . In this device, the weight support rod 14 of the load adding device and the load removing device 20 are connected by the shaft 22, so when the lower end of the sample S' ₁ is clamped with the clamp fitting CMM ₁ , a load is applied to the sample and the gripping part 23, 23
By grasping the lower end of the CMM 1 and opening the clamp fitting CMM ₁ , the load is removed, and therefore the load can be added and removed from outside the thermostatic chamber. In the above-described embodiment as well, a knife or the like may be used to cut the sample S′ ₁ between the lower end of the length-measuring region and the upper end of the clamp fitting CMM ₁ . As described above, according to the present invention, there are a means for applying a constant load to a sample made of rubber or the like, a means for instantaneously removing the load, and length data corresponding to the length of elongation or contraction of the sample. A signal processing circuit that generates an electrical signal, and a data processing circuit that has an arithmetic and control function that captures and stores length data inputted from the signal processing circuit at predetermined time intervals after the signal processing circuit is provided. Therefore, it is possible to measure the fist movement of the sample as a function of time when a constant load is applied to the sample and when the load is removed, and it is possible to obtain the data necessary for the rubber sample, such as viscous properties and elastic properties. , it has the advantage of being able to automatically know the properties of rubber.

[Brief explanation of the drawing]

FIGS. 1 and 2 are diagrams explaining the principle of the present invention, showing the sample surface and the waveform of an electric signal, respectively. FIG. 3 is a block diagram of an electric circuit showing an example of the present invention. FIG. Fig. 3 is a diagram showing the field of view of the TV camera and the waveform of the electrical signal by the device, Fig. 5 is an explanatory diagram when a length reference plate is provided, and Fig. 6 is an electrical diagram showing another embodiment of the present invention. Circuit block diagram, No. 7
The figure shows the field of view of the TV camera and the waveform of the electric signal by the device shown in Fig. 6, Fig. 8 is a block diagram showing an example of the data processing circuit, Fig. 9 is an explanatory diagram of the operation of the data processing circuit, and Fig. 10 11 is a front view showing an example of the test machine main body, and FIG. 11 is a right side view of FIG. 10. 1...TV camera, 2...Reference signal generator, 3
...Signal discriminator, 4...Signal processing circuit, 5...Data processing circuit, 20...Load removal device, S, S'...
...sample, Q...marked line, Q'...mark area, W ₁ ,
W ₂ ... Weight.

Claims (1)

[Claims] 1. Applying a certain load to a sample whose length measurement area is an area between at least two marked lines with different optical properties from the surface, and/or a sample whose length measurement area is an area whose optical properties are different from other areas. a load applying means for applying;
a load removing means for removing the load applied to the sample; and a load removing means for scanning the elongation due to the application of the load and the contraction due to the removal of the load of at least one of the samples to generate an electric signal corresponding to the optical characteristic of the scanned location. a scanning device to output a measurement range instruction signal based on an output signal of the scanning device and/or a reference signal for scanning by the scanning device; a signal processing circuit that generates an electrical signal that is length data corresponding to the length of the length-measured region; and a data processing circuit that captures and stores the length data input from the signal processing circuit at predetermined time intervals. A creep test device characterized by comprising: