JP5098960B2 - Material testing machine and test force display device - Google Patents

Description

  The present invention relates to a material testing machine that measures a test force without a range, and a test force display device that displays the test force based on rangeless measurement data.

  In general, a test force value measured by a material testing machine is equipped with a range corresponding to an amplification factor of a test force amplifier in order to improve measurement resolution performance (see, for example, Patent Document 1). In the case of a testing machine equipped with an analog type indicator for the test force indicator, the range of the test force value indicated by the full scale of the indicator changes according to the switching of the range.

  In recent years, S / N has been improved by increasing the resolution of an A / D converter and increasing the accuracy of an amplifier, and sufficient measurement resolution has been obtained without necessarily using a range. In such a rangeless testing machine, when an analog type indicator equipped with a pointer as a test force indicator is equipped, one round of the indicator becomes a testing machine capacity and the usability is deteriorated. Therefore, a rangeless testing machine generally displays the test force value digitally.

JP-A-64-83132

  In a material testing machine having a conventional range, the test force speed is adjusted while observing the movement of the analog pointer during a material test by manual operation. However, in a rangeless material testing machine equipped with a digital display, there is a problem that it is difficult to confirm a change in test force due to the digital display and fine adjustment becomes difficult.

A material testing machine according to a first aspect of the present invention includes a load device that applies a load to a test piece, a sensor that detects a test force by the load device, and an amplifier that amplifies a detection signal of the sensor at an amplification factor fixed to a predetermined value And a data acquisition means having an AD converter for converting the signal amplified by the amplifier from an analog value to a digital value, and taking the detection signal of the sensor as measurement data in a rangeless manner, and a guideline for displaying the test force Display with indicator, operation member that indicates the display range for setting the full scale of the display with pointer, and pointer drive that controls the driving of the pointer based on the measurement data according to the display range specified by the operation member Means.
According to a second aspect of the present invention, there is provided a test force display device comprising: an amplifier that amplifies a detection signal input from a test force detection sensor of a material testing machine with an amplification factor fixed to a predetermined value; and a signal amplified by the amplifier. An AD converter that converts analog values to digital values, a display with a pointer that displays the test force, an operation member that indicates the display range for setting the full scale of the display with a pointer, and conversion using the AD converter And a pointer driving means for controlling the driving of the pointer based on the received signal in accordance with the display range instructed by the operation member.

  According to the present invention, in a rangeless material testing machine, it is easy to visually check the change state of the test force.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a material testing machine in the present embodiment, and is a schematic diagram showing a testing machine main body 1 and a measurement control device 2. FIG. 1 shows a setting state for a tensile test.

  The testing machine main body 1 has two screw rods 7 and two struts 8 arranged vertically. The screw rod 7 and the column 8 are respectively arranged on the diagonal line of the rectangular table 4, and in FIG. 1, the screw rod 7 and the column 8 arranged on the near side in the figure are arranged side by side. The upper cross head 6 is fixed to the two columns 8. The lower cross head 5 is held by the two screw rods 7 so as to be movable up and down. The upper crosshead 6 and the lower crosshead 5 are equipped with gripping tools 11a and 11b for gripping the test piece TP.

  Two screw rods 7 to which the lower cross head 5 is attached are erected on the bed 3. Two struts 8 to which the upper cross head 6 is fixed are erected on the table 4. A load cylinder 10 is fixed to the center of the bed 3. A ram 12 connected to the table 4 is fitted in the load cylinder 10. Therefore, when pressure oil is sent from the hydraulic device 30 to the load cylinder 10, the ram 12 rises. That is, the table 4, the support column 8, and the upper cross head 6 are lifted together, and a tensile force is applied to the test piece TP gripped by the upper and lower grippers 11a and 11b. Conversely, when the pressure oil is returned to the oil tank 304 of the hydraulic device 30, the ram 12 is lowered. Reference numeral 13 denotes a pressure cell, which is a converter that converts the hydraulic pressure in the load cylinder 10 into an electrical signal, and the output signal is input to the measurement control device 2.

The lower cross head 5 is provided with an elevating motor (not shown), and the elevating motor is driven to adjust the vertical position of the lower cross head 5 when the test piece TP is mounted on the gripping tools 11a and 11b. The hydraulic device 30 is provided with a load pump 301, a pump motor 302, a load control valve 303, and an oil tank 304. Load pump 3 01, gear pump is used. The load control valve 303 is an integrated safety valve, pressure adjustment valve, and flow rate adjustment valve.

  The measurement control device 2 that controls the operation of the test machine main body 1 is provided with a load operation panel 21, a display range switching panel 22, and a test force indicator 23. By operating the load control knob 211 provided on the load operation panel 21, the flow rate adjusting valve provided on the load control valve 303 can be adjusted.

  FIG. 2 is a diagram showing the test force indicator 23, the display range switching panel 22 and the load control knob 211 provided in the measurement control device 2. The test force indicator 23 shown in FIG. 2A is provided with a test force indicator 231, a minimum scale indicator 232, and five divisional scale indicators 233 as analog indicators, and a test force indicator 234 as a digital indicator. And a test force peak hold indicator 235 is provided.

The test force indicator 231 is an analog display of the current test force value, and is rotated by a stepping motor or a servo motor. Further, the division scale display 233 digitally displays the test force values at the five division positions of the full scale (one turn ) of the scale board. On the other hand, the current test force value is digitally displayed on the test force indicator 234. The test force peak hold indicator 235 holds the maximum test force value up to the present and displays it digitally.

  The display range switching panel 22 shown in FIG. 2B is provided with a test force range selector 221 and a peak hold reset switch 222. The peak hold reset switch 222 is a switch for canceling the peak hold value so far. When the peak hold reset switch 222 is operated, the display of the above-described test force peak hold indicator 235 is reset.

  In the test machine of the present embodiment, when measuring the test force from the pressure cell based on the detection signal, the detection signal is captured as measurement data in a rangeless manner. As with a testing machine equipped with a range, the display can be switched between a plurality of ranges. In the present embodiment, this range is referred to as a virtual display range in distinction from a conventional range relating to weighing.

  Here, six virtual display ranges are provided, and by pressing any of the six switches 221a to 221f provided in the test force range selector 221, the test force value for full scale can be switched to six steps. it can. When the virtual display range is determined, the digital display of the five divided scale displays 233 and the minimum scale display 232 of the test force indicator 23 is switched according to the virtual range.

  In FIG. 2C, “RETURN”, “HOLD”, “LOAD”, and “OPEN” are displayed on the panel with respect to the load control knob 211. When the load control knob 211 is set to a position of “LOAD” to “OPEN”, the ram 12 (see FIG. 1) rises, and as it approaches “OPEN”, the amount of oil feeding increases and the rising speed of the ram 12 increases. When the load control knob 211 is turned in the direction of “RETURN”, the ram 12 is lowered. Further, when the ram 12 is stopped at the same position, the position of the load control knob 211 is set near “HOLD”.

  FIG. 3 is a block diagram illustrating a configuration of the measurement control device 2. The pressure detection signal input from the pressure cell 13 is amplified by the amplifier 24 and then converted from an analog value to a digital value by the A / D converter 25. In the case of a material testing machine having a conventional range, the amplifier that amplifies the pressure detection signal can switch the amplification magnification to a plurality of values, and performs measurement and display in a measurement range corresponding to each amplification magnification. On the other hand, in the present embodiment which is a rangeless tester, the amplification factor of the amplifier 24 is fixed to a predetermined value. This is because measurement with the same resolution as when the amplification factor was increased with a conventional testing machine with a range even when the test force value was small due to high resolution of the A / D converter and high precision of the amplifier. Since it can be performed, the rangeless configuration is as described above.

The pressure detection signal converted into a digital signal by the A / D converter 25 is input to the control unit 26. The control unit 26 is provided with a display control circuit 261 and a load control circuit 262, and operation signals are input from the load operation panel 21 and the display range switching panel 22. Load control circuit 262, rise of the ram 12 by controlling the load control valve 30 3, drop, and controls the stop. When a load is applied to the test piece TP, there are a manual operation performed by the user operating the load control knob 211 and an auto operation for automatically applying a load according to a predetermined procedure preset in the control unit 26. In the case of manual operation, the load control circuit 262 controls the load control valve 303 according to the operation of the load control knob 211, and in the case of auto operation, controls the load control valve 303 based on a predetermined procedure set.

  The display control circuit 261 outputs a display control signal to each of the analog display 23A and the digital display 23D provided in the test force indicator 23. 2 corresponds to the analog indicator 23A, the minimum scale indicator 232 and the five divisional scale indicators 233, and the digital indicator 23D corresponds to the test force indicator 234 and the test force of FIG. The peak hold indicator 235 corresponds. The display control of the analog display 23A is performed based on an operation signal from the test force range selector 221, that is, based on a virtual display range selected by operating the switches 221a to 221f. The display control circuit 261 calculates the amount of rotation of the test force indicator 231 per unit measurement data based on the measurement data and the virtual display range, and drives the motor for driving the test force indicator 231.

  FIG. 4 is a flowchart for explaining display control of the analog display 23 </ b> A executed by the control unit 26. In the following description, the maximum capacity of the testing machine is 200 kN, and the virtual display ranges that can be selected by the switches 221a to 221f of the test force range selector 221 are six stages of 200 kN, 100 kN, 40 kN, 20 kN, 10 kN, and 4 kN.

  The flowchart of FIG. 4 shows the case of the automatic operation. When measurement is started, the process starts and step S100 is executed. In step S100, the virtual display range is set to a minimum of 4 kN. Accordingly, one round (full scale) of the test force indicator 231 in FIG. 2 corresponds to 0 to 4 kN, and each division scale indicator 233 provided at the five division positions is clockwise from the 12 o'clock position, Numerical values “4.0”, “0.8”, “1.6”, “2.4”, and “3.2” are displayed in order.

In step S200, the measurement data converted into a digital value by the A / D converter is read and the test force is obtained. In step S300, the test force indicator 231 is rotationally driven based on the measured test force. In step S400, the measured test force is compared with a value obtained by multiplying the virtual display range R by 0.95. If “test force> 0.95R”, the process proceeds to step S500, where “test force ≦ 0.95R. ", The process proceeds to step S700. In the present case, since the virtual display range R is a 4 kN, if the test force is greater than 3.8kN proceeds to step S 5 00. Here, the condition for switching the virtual display range is “test force> 0.95R”, but the present invention is not limited to this. For example, “test force> R” may be used.

  When the process proceeds from step S400 to step S500, the virtual display range is switched to the upper stage range (10 kN), and then the process proceeds to step S600, where the display of the analog display 23A is based on the switched virtual display range. Switch to display. That is, the display of the division scale display 233 is “10.0”, “2.0”, “4.0”, “6.0”, “8.0” in order from the 12 o'clock position. The position of the test force indicator 231 and the display of the minimum scale indicator 232 are also changed corresponding to the virtual display range 10 kN.

  When the virtual display range is switched, the display control circuit 261 switches the rotation speed of the motor that rotationally drives the test force indicator 231 based on the measurement data and the virtual display range. For example, when the virtual display range is switched from 4 kN to 10 kN, the rotation speed of the test force indicator 231 with respect to a change in the test force is reduced to 0.4 times faster. That is, the change in the test force can be easily recognized visually as the moving speed of the test force indicator 231.

  In step S700, it is determined whether or not the measurement has been completed. If it is determined that the measurement has not been completed, the process returns to step S200, and if it is determined that the measurement has been completed, the series of processes is terminated. The test force indicator 234 and the test force peak hold indicator 235 of the test force indicator 23 are digitally displayed based on the rangeless measurement data.

  In FIG. 4, the automatic operation is described as an example. However, when the manual operation is performed in a predetermined virtual display range, when the virtual display range is selected by the test force range selector 221, the display of the analog display 23A is selected. Switch to correspond to. The change in the test force due to the operation of the load control knob 211 can be easily recognized by the test force guide 231. Therefore, the operation amount of the load control knob 211 is adjusted while looking at the test force guide 231.

  As described above, in the present embodiment, the analog indicator 23A with a pointer for displaying the test force is provided, and the test force range selector 221 instructs to drive the test force pointer 231 based on the measurement data taken in a rangeless manner. Since the display control circuit 261 performs control according to the virtual display range that has been set, when the test force is small, the virtual display range is reduced and the movement of the test force pointer 231 is expanded, so that during the material test, The occurrence of singular points (yield points, etc.) can be easily read. In other words, even with a rangeless material testing machine, by providing a virtual display range, it is possible to achieve the same usability as a material testing machine with a range for displaying measured values. Easy to use for users familiar with the machine.

  In addition, even in a rangeless material testing machine having only a digital display for the test force, the analog display 23A with a pointer for displaying the test force and the analog display 23A (test force guide 231) are full. The test force range selector 221 for instructing the display range for setting the scale and the driving of the test force pointer 231 based on the measurement data captured without the range are in accordance with the virtual display range instructed by the test force range selector 221. By controlling the above, it is possible to achieve the same effect as the material testing machine described above.

  In addition, the above description is an example to the last, and this invention is not limited to the said embodiment at all unless the characteristic of this invention is impaired. For example, a test force indicator 231, a scale, a division scale display 233, etc. as shown in FIG. 2A may be displayed using a liquid crystal display panel. In this case, although the movement of the pointer is strict, it is possible to visually check the change of the test force by displaying the analog rotation of the pointer.

It is a figure which shows one Embodiment of the material testing machine by this invention. It is a figure explaining the measurement control apparatus 2, (a) shows the test force indicator 23, (b) shows the weighing switching panel 22, (c) shows the load control knob 211, respectively. 3 is a block diagram showing a configuration of a measurement control device 2. FIG. It is a flowchart for demonstrating the display control of 23 A of analog displays.

Explanation of symbols

1: Test machine body, 2: Measurement control device, 10: Load cylinder, 12: Ram, 13: Pressure cell, 21: Load operation panel, 11: Range switching panel, 23: Test force indicator, 23A: Analog display , 23D: digital display, 24: amplifier, 25: A / D converter, 26: control unit, 211: load control knob, 221: test force range selector, 231: test force guide, 232: minimum scale display, 233 : Division scale display, 234: test force display, 235: test force peak hold display, 261: display control circuit, 262: load control circuit, 303: load control valve, TP: test piece

Claims (2)

A load device for applying a load to the test piece;
A sensor for detecting a test force by the load device;
An amplifier for amplifying the detection signal of the sensor at an amplification factor fixed to a predetermined value, and an AD converter for converting the signal amplified by the amplifier from an analog value to a digital value. Data acquisition means for capturing signals as measurement data without a range ;
A display with a pointer for displaying the test force;
An operation member for instructing a display range for setting the full scale of the indicator-equipped indicator;
A material testing machine, comprising: a pointer driving unit that controls driving of the pointer based on the measurement data in accordance with a display range instructed by the operation member. An amplifier that amplifies the detection signal input from the test force detection sensor of the material testing machine at an amplification factor fixed to a predetermined value;
An AD converter for converting the signal amplified by the amplifier from an analog value to a digital value;
An indicator with indicator to display the test force;
An operation member for instructing a display range for setting the full scale of the indicator-equipped indicator;
A test force display device comprising pointer driving means for controlling driving of the pointer based on a signal converted by the AD converter according to a display range instructed by the operation member.

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