JPH0436435Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a correction device for correcting a shift in gauge position caused by movement of a crosshead of a material testing machine.

(Prior Art) When performing a tensile test using a material testing machine, a gauge position is used as a reference position, a test piece is attached to a grip at the gauge position, and a load is applied by moving the crosshead. When the test is finished, the crosshead is returned to the gage position and a new test piece is set.

By the way, when taking comparative data for multiple test pieces, if the stroke detection for the gauge position is not accurate, errors will occur in the measured values of individual test pieces and the comparison will be inaccurate. must be carried out strictly. On the other hand, in terms of test efficiency, it is preferable to return the crosshead from the test end position to the gauge position as quickly as possible, so in actual tests the crosshead is returned at a fairly high speed, but at this time the crosshead does not overshoot. Therefore, it is normal for the return position to deviate slightly from the initial gauge position. The value of this deviation can be read as long as stroke detection is performed accurately, and as long as the test is repeated without turning off the power to the device, the correlation between the test end position and the gauge position will depend on the individual specimens. This is not a problem since both are held at the same time.

(Problem that the invention aims to solve) However, when testing a test piece of the same shape over several days, when the power of the device is turned on and off while the test continues, the power must be turned off. Even if the stroke detection device detects a deviation from the initial gauge position of the crosshead that has returned to the gauge position before turning off, the power must be turned off once.
There was a problem in that when it was turned off and then turned on again, it was set to be stopped at the gauge position with no deviation and zero error. For this reason, the comparison of data before and after the power was turned off became inaccurate, and when these ON and OFF times overlapped, the overshoot amount was accumulated, making the comparison even more inaccurate.

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

That is, the gauge position correction device according to the present invention includes a stroke detection means for detecting the amount of movement of the crosshead of a material testing machine, a counter for counting the amount of movement detected by the detection means, and a A memory that stores the counted stroke value, a backup power supply that continues to independently supply power to the memory even when the test machine is turned off, and a new crosshead movement amount detected by the stroke detection means. The stroke value stored in the memory is added to the stroke value as a variation, and the calculation means outputs the sum as a new stroke display value.

(Function) The memory stores the displayed value representing the current position of the crosshead, and when the power is turned off and then turned on again, the displayed value stored in the memory is treated as a deviation. On the other hand, the counter is powered
It is reset to zero by ON. When the test is restarted and the crosshead moves, the amount of movement is detected by the stroke detection means. At this time, the above-mentioned variation is added to the count value counted by the counter, and the sum is output as a new display value. be done.

(Embodiment) FIG. 1 is a configuration explanatory diagram showing one embodiment of the present invention, and this gauge position correction device 1 includes a stroke detector 5 that detects the stroke of a crosshead 3 of a material testing machine 2, and a stroke detector 5 that detects the stroke of a crosshead 3 of a material testing machine 2. It is equipped with a stroke counter 6 for counting the stroke value, an input/output device I/O, an arithmetic device MUP, ROM, RAM, and a battery 11 as a backup power source that independently supplies power to the RAM.

The test piece 13 has the crosshead 3 at the gauge position P.
It is attached to the upper and lower grips 15 and 16 when located in the upper and lower positions. The crosshead 3 is moved upward by a drive device (not shown), and a tensile load is applied to the test piece 13. Assuming that the position of the crosshead 3 when the first test piece is set is the initial gauge position, the amount of movement of the crosshead from that position to the test end position for that test piece is detected by the stroke detector 5, and is recorded in the counter 6. It is then counted. The stroke value counted at that time represents the displacement of the test piece 13.

When the test is completed, the crosshead is returned to the gauge position P, but at this time a slight deviation occurs between the initial gauge position and the stop position due to overshoot. However, the displacement of the test piece is determined by the stroke value from the gauge position where the test piece is set to the test end position, and the stroke value, including the shift in the gauge position, can be read accurately, so there is no need to turn off the power. As long as the test is continued, slight deviations in gauge position will not adversely affect test accuracy.

Next, if the power is turned off while the test is continuing, such as when the test day spans two days, the counter 6 is reset and the counter value becomes zero when the power is turned on again. Therefore, as far as the counter 6 is concerned, the position where the crosshead is currently stopped is set as the initial gauge position. However, this device is provided with a memory (RAM) 10 that always stores a display value representing the current position of the crosshead.
0 is backed up by the battery 11 independently of the device power supply, so data indicating the crosshead position before the power is turned off is saved. Then, when the device is powered on again, this memory value is supplied as a difference to the arithmetic unit 8, added to the newly counted stroke value, and the sum is output as a display value to a display device (not shown). .
This display value is subsequently stored in memory 10.

The above explanation takes as an example the deviation from the initial gauge position due to overshoot when the crosshead is returned to the gauge position, but the crosshead is stopped at another position for other reasons and the device power is turned off. The situation is the same when the tester is turned off, and when the power is turned on again, the stopping position relative to the initial gauge position is known, making operation of the tester extremely easy.

(Effects of the invention) As is clear from the above explanation, the gauge position correction device according to the invention eliminates errors due to crosshead overshoot caused by turning the power of the device on and off during testing. Erase,
It has become an excellent tool for obtaining accurate test data.

[Brief explanation of the drawing]

FIG. 1 is a configuration explanatory diagram showing one embodiment of the present invention, and FIG. 2 is a flowchart showing the operation. 2...Material testing machine, 3...Crosshead, 5...
...Stroke detector, 6...Counter, 10...
Memory, 11...Battery, 13...Test piece.

Claims (1)

[Scope of utility model registration request] A stroke detection means for detecting the amount of movement of a crosshead of a material testing machine, a counter for counting the amount of movement detected by the detection means, a memory for storing the stroke value counted by the counter, and a test device. A backup power supply that continues to independently supply power to the memory even when the machine is turned off, and a stroke value stored in the memory that changes the stroke value to the new crosshead movement detected by the stroke detection means. A gauge position correction device for a materials testing machine, comprising calculation means for adding the difference and outputting the sum as a new stroke display value.