JPS63243833A - Material tester - Google Patents

Abstract

PURPOSE:To measure displacement in various tests by the same displacement sensor by installing a displacement sensor which follows up the deviation of a cross-head side gauge mark and a displacement sensor which follows up the deviation of a table side gauge mark on the side of a tester main body. CONSTITUTION:A couple of screw beams are implanted in a table 1 and a cross head 4 is provided movably in an up/down direction through a nut 3. The table 1 is provided with a gripper 6 and the cross head 4 is provided with a gripper 9. A coupled of displacement sensors RL1 and RL2 consisting of rotary encoders are provided on the table 1 and the cross head 4 is provided with a couple of displacement sensors RU1 and RU2. Gauge mark metal fittings 12 (12U and 12L) connected between gauge marks of a body TP to be tested are coupled by respective pulleys of the displacement sensors RU1 and RU2, and RL1 and RL2 and a wire 14, and the pulleys rotate according to the displacement of the gauge mark metal fittings 12, so that the respective displacement sensors RU1 and RU2, and RL1 and RL2 output signals corresponding to the quantity of rotation.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a material testing machine used for tensile tests, etc., and is improved to particularly improve workability and accuracy in measuring displacement of specimens.

B. Conventional technology Two screw rods are set up on a table to allow the crosshead to move up and down, and a load is applied to the specimen placed between the lower grip on the table and the upper grip on the crosshead. Material testing machines are known. In this material testing machine, elongation and the like are detected by placing contacts in contact with the upper and lower gauge points of the specimen, and detecting the displacement of the contacts using a differential transformer, strain gauge, etc.

When performing compression tests by replacing the upper and lower grips with upper and lower pressure plates, or when performing bending tests by replacing the upper and lower grips with upper and lower punches, a dedicated displacement meter with the same structure is replaced each time. Furthermore, another displacement meter may be used that measures the displacement of the specimen by directly measuring the displacement between the table and the crosshead using a differential transformer or the like.

C1 Problems to be Solved by the Invention However, it is necessary to prepare separate displacement meters for each of the above various tests, change the installation location, and open the electrical system each time, making it difficult to use a common displacement meter. It was hoped that improvements would be made in the process and workability.

An object of the present invention is to provide a material testing machine that eliminates such problems.

Means for Solving Problem D1 The first invention is implemented in a material testing machine that loads a specimen installed between a table and a crosshead, and tracks the displacement of a gauge on the crosshead side of the specimen. It has a first displacement sensor that moves, and a second displacement sensor that follows the displacement of a gauge point on the table side, and the first displacement sensor is installed on the crosshead and the second displacement sensor is installed on one table. It is something. A second invention is one in which the first and second displacement sensors are installed in a crosshead.

86 action 1st. Since the second displacement sensor is installed in advance on the testing machine main body side, when performing various tests, it is only necessary to connect the specimen and the displacement sensor with a connecting body such as a wire. Because it is used, every time various tests are conducted,
There is no need to adjust the electrical system as in the past, improving work efficiency.

F. Example One embodiment will be described with reference to FIGS. 1 and 2.

A pair of screw rods 2 are erected on the table 1, and a crosshead 4 is screwed together through a nut 3 so as to be movable up and down. A lower grip 6 is erected on the table 1 via a fixed shaft 5, and an upper grip 9 is suspended from the crosshead 4 via a rotor self and a load shaft 8. A pair of rotary encoders (displacement sensors) RLI and RL2 are installed on the table 1, and a pair of rotary encoders RUl and RU2 are installed on the crosshead 4, respectively. Gauge fittings 12U and 12L (hereinafter referred to as 12
) is connected to each pulley 13 of the rotary encoders RU and RL by a wire 14, and the pulley 13 rotates according to the displacement of the gauge metal fitting 12, and the rotary encoder RU,
RL outputs a signal according to the amount of rotation.

As shown in FIG. 2, the output of the rotor self is input as a load X to the XiM of the recorder 22 via the load amplifier 21. Upper pair of rotary encoders RUI, RU2
The outputs U and U2 are averaged by the average value circuit 23U and inputted to the arithmetic circuit 24 as the elongation U of the gauge point on the crosshead side.
, RL2's output L, L2 is also averaged by the average value circuit 23L, and calculated as the elongation L of the gauge point on the table side by the arithmetic circuit 24.
is input. The arithmetic circuit 24 includes a gauge distance setting device 25.
Distance information OL is also input from , and GL+(U+L) is calculated and input as the elongation Y of the specimen to the Y axis of the recorder 22.

Prior to the test, first, a predetermined gauge distance GL is input from the gauge distance setter 25 to the arithmetic circuit 24. When the screw rod 2 is rotated and the crosshead 4 is raised, a tensile load is applied to the specimen TP, and the output from the rotor self is sent to the recorder 22 as load information via the load amplifier 21.
is input to the X axis of At this time, each rotary encoder RLI.

The pulleys 13 of RL2, RUI, and RU2 are connected to various point fittings 12.
Each rotary encoder outputs U, U2, Ll, and L2. Average value circuit 23U,
23L calculates average values U and L from the following, respectively, and inputs them to the calculation circuit 24.

The calculation circuit 24 calculates the extension Y from Y=GL+, (U+L) and inputs it to the Y axis of the recorder 22. Therefore, the load-elongation characteristics shown in the figure are drawn on the recorder 22. Note that in reality, the pulses from the rotary encoder are counted, this count value is converted to elongation, and the average value U is output. Alternatively, each average value circuit averages the count values and sends it directly to the arithmetic circuit 24. At the same time, the gauge distance OL is also converted into the number of pulses and inputted, and the arithmetic circuit 24 converts the number of pulses into elongation Y.

FIG. 3 shows the platens 31 and 32 connected to the fixed shaft 5 and the load shaft 8, respectively, with the upper and lower grips removed.
．． One end of the wire 14 is fixed to the pulley 13 of the rotary encoder RUI, RU2, RLI, RL2.
It is connected to. Rotary encoder RU, RL
is installed on crosshead 4 and table 1, so
Replace the grips 6 and 9 with platens 31 and 32 and remove the wire 14.
Displacement measurement can be prepared simply by winding the wire around the pulley 13, and there is no need for gain adjustment or zero point adjustment of the electrical system, resulting in good workability.

Furthermore, in the test, the distance GL between the gauges and the platen is inputted from the distance setting device 25.

When the specimen TP is compressed through the platens 31 and 32, the specimen TP is deformed, and the rotary encoder RUI is deformed.

RU2, RLI, and RL2 rotate in accordance with the amount of deformation and output pulses. Based on this pulse, the amount of compression is detected in the same manner as described above.

In addition, as shown in Figure 4, the upper and lower rotary encoders R
Each wire 14 of UI, RU2, RLI, and RL2 is designated by code 1.
It is also possible to measure the displacement of the specimen TP by connecting them as shown in 4a and detecting the displacement of the crosshead 4 with a rotary encoder. In this case, zero is input as the gauge distance OL.

In this case as well, the displacement sensor can be used simply by connecting the wire 14, and the workability is good.

Furthermore, a pair of three-point bending jigs 41.4 as shown in FIG.
2 can be attached in place of the grips 6 and 9, and the three-point bending jigs 41 and 42 can be connected to the rotary encoders RU and RL via the wires 14 as in FIG. In this case as well, workability is good as described above.

FIG. 6 shows an embodiment of the second invention.

This has a pair of rotary encoders RUI, RU2, RLI, and RL2 installed on a crosshead 4 to track various points above and below. The rest is the same as the first invention, and the explanation will be omitted. In this embodiment, the rotary encoder rotates by the difference between the amount of movement of the crosshead 4 and the amount of displacement of the test piece, so even in tests with large displacements, the amount of rotation of the rotary encoder can be reduced and measurement resolution can be improved.

In each invention, instead of the rotary encoder, a rotation detection sensor such as a potentiometer or a synchro motor, or a linear sensor such as a differential transformer, an electric micrometer, or an electric dial gauge may be used. It can also be applied to a device in which the crosshead is fixed and the load is applied by a load actuator on the table side.

G0 Effects of the Invention Since the present invention is configured as described above, the displacement in various tests can be measured using the same displacement sensor, and there is no need to replace the displacement sensor or adjust the gain for each type of test, which improves work efficiency. It is possible to provide a material testing machine with improved performance and ease of use.

[Brief explanation of the drawing]

Figures 1 to 5 show an embodiment of the first invention, Figure 1 is a front view of the material testing machine, and Figure 2 is a block diagram of the electrical system. Line sectional views, Figures 3 to 5
The figures are views taken along the line ■--■ in FIG. 1, showing various test modes, and FIG. 6 is a schematic configuration diagram showing an embodiment of the second invention. 1: Table 2: Screw rod 4: Crosshead 5: Fixed shaft 6.9: Grip 8: Load shaft 12U, 12L: Gauge fitting 13: Pulley 14: Wire
22: Recorder 23U, 23L: Average value circuit 24: Arithmetic circuit 25: Gauge distance setting device Patent applicant Shimadzu Corporation Representative Patent attorney Fuyuki Nagai Figure 3

Claims (1)

[Claims] 1) In a material testing machine that loads a specimen installed between a table and a crosshead, a first displacement sensor that tracks the displacement of a gauge point on the crosshead side of the specimen; and a second displacement sensor that follows the displacement of a gauge point on the table side, the first displacement sensor being disposed on the crosshead and the second displacement sensor being disposed on the table. 2) In a material testing machine that loads a specimen installed between a table and a crosshead, a first displacement sensor that follows the displacement of a gauge on the crosshead side of the specimen, and a gauge on the table side. a second displacement sensor that tracks the displacement of the material, and the first and second displacement sensors are installed in a crosshead.