JPH0545961Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an ultra-fine material testing machine, and more particularly to an ultra-fine material testing machine having a wide measurement range of the indentation depth of an indenter.

[Prior Art] Conventionally, ultra-fine material testing machines that measure the hardness of samples press an indenter against the measurement surface of the object using a variable load mechanism that applies a minute load, and measure the amount of displacement of the indenter, that is, the indentation depth. I am trying to measure the A differential transformer type displacement detector is normally used as an indenter displacement detector.

[Problems to be solved by the invention] The displacement measurement range of the differential transformer type displacement detector described above is usually 20 μm, but it has a function to detect the moment the indenter contacts the test piece and measures the indentation depth. Because the differential transformer has both functions, the measurement range of the indentation depth was limited to a narrow range of 5 μm. In addition, in conventional equipment, an optical monitor is provided as an auxiliary device, and the optical monitor determines the test position of the specimen placed on the sample stage, and the sample stage is rotated and held at the load position. However, if the height adjustment due to the rotation of the sample stage deviates, the measurement range of the differential transformer type displacement detector, which has a narrow measurement range as described above, may fall outside the measurement range, and in this case, the indenter There was a problem in that the indentation depth could not be measured and the test itself could not be performed.

Therefore, an object of the present invention is to provide an ultra-fine material testing machine that can measure the indentation depth of an indenter over a wide range.

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

In other words, the ultra-fine material testing device according to the present invention presses an indenter against a test object using a variable load device that can arbitrarily apply a minute load, and determines the amount of displacement of the indenter using a displacement detector. In the micro material testing machine, the displacement detector is composed of a plurality of differential displacement detectors, which are connected in series, so that the upper limit of the measurement range of the first displacement detector is equal to the upper limit of the measurement range of the second displacement detector. The present invention is characterized in that the outputs of the plurality of differential displacement detectors are sequentially adjusted so as to coincide with the zero point, and that a selection means is provided for selecting the outputs of the plurality of differential displacement detectors.

[Function] The displacement of the indenter is measured by the first differential displacement detector provided on the indenter side, and if the displacement exceeds this measurement range, the measurement range of the first differential displacement detector is changed. A displacement signal is output from the second differential displacement detector from the point in time when the displacement is exceeded, and the selection means selects this signal. In this way, since the plurality of differential displacement detectors having different measurement ranges sequentially measure the displacement of the indenter, the displacement of the indenter can be measured over a wide range as a whole.

[Example] Figure 1 shows a self-balancing electronic balance type loading device 1 of an ultra-fine material testing machine that is an example of the present invention.
This is a schematic diagram showing the configuration of a balance 2 whose central part is supported by a knife edge 5, and a pyramid-shaped indenter 6 at one end of the balance 2, which works with a solenoid 3 at the other end to generate electromagnetic force. Iron core 7 is attached. Two differential transformer-type displacement detectors 9 and 10 are provided above the indenter 6 to detect displacement on the surface of the sample 16 pressed by the indenter 6 while a load is being applied.

The two displacement detectors 9 and 10 are connected so that cores 9A and 10A made of magnetic material move in conjunction with the displacement of the indenter 6, and one displacement detector 9 (with a measurement range of 0 ~20 μm) is adjusted so that when the core 9A of the displacement detector 10 is at the zero point position of the measurement range, the core 10A of the other displacement detector 10 is located 20 μm above the measurement range of the displacement detector 10. There is. That is, the upper limit of the measurement range of the first displacement detector 9 is adjusted to match the zero point of the second displacement detector. Such adjustments can be made by moving the coil section of the displacement detector up and down.
This can be done in the same way as the adjustment of conventional displacement detectors.

FIG. 2 is a block diagram showing the configuration of a processing circuit for signals output from two displacement detectors 9 and 10. The output signals of each displacement detector 9 and 10 are amplified by an amplifier 11, and these output signals are A/
The data is A/D converted by the D converter 13 and sent to the CPU 14. The displacement of the normal indenter 6 is measured by a displacement detector 9 provided on the indenter 6 side. For the displacement that has finished this measurement range, a displacement signal is output from the displacement detector 10 when the core 9A exceeds the measurement range, so it is switched by the multiplexer 12, and the CPU 14
The amount of displacement of the indenter 6 is calculated by adding the signal from the displacement detector 10 to the displacement signal from the displacement detector 9. The calculated displacement amount is recorded by a recorder 15 (not shown). Since the output voltage of the displacement detector does not change if it is outside the measurement range, it is possible to determine which detector is operating by checking the output voltage. When the multiplexer 12 is not used, the A/D converter 13 may be used for two channels to send signals to the CPU 14.

In the above embodiment, two displacement detectors are used, but three or more can also be used. By connecting and arranging the displacement detectors as described above, the measurement range can be expanded by the number of displacements that can be measured with one displacement detector, depending on the number of displacement detectors used. In addition, although the displacement detectors are arranged in series in the embodiment, they may be connected and arranged so that the movable parts move continuously within the measurement range of each displacement detector, or in some cases they may be arranged in parallel. You can. Furthermore, it may be installed at the position of another member of the movable rod of the balance.
In this case, it is necessary to adjust the relationship between the movable amounts.

Furthermore, the present invention was tested by providing an optical monitor as an auxiliary device, using the monitor to position the indenter with respect to the test piece on the rotating sample stage, and rotating the sample stage to bring it to the loading position. If this method is implemented in a machine, the measurement range of the displacement detector will be widened, making it possible to easily adjust the height by rotating the sample stage.

[Effects of the invention] As is clear from the above explanation, the ultra-fine material testing machine according to the invention allows multiple displacement detectors to be selectively used in a single test, and the indentation depth of the indenter can be varied over a wide range. It has become possible to measure across the board.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the configuration of the essential parts of an ultra-fine material testing machine which is an embodiment of the present invention, and FIG. 2 is a block diagram showing the number of times an output signal from a displacement detector is processed. 9, 10...Displacement detector, 9A, 10A...Core, 12...Multiplexer (selection means), 14
……CPU.

Claims (1)

[Scope of utility model registration request] This ultra-micro material testing machine presses an indenter against the test piece using a variable load device that can apply any minute load, and determines the amount of displacement of the indenter using a displacement detector.The displacement detector is composed of a plurality of differential displacement detectors that are connected in series, and are sequentially adjusted so that the upper limit of the measurement range of a first displacement detector coincides with the zero point of a second displacement detector, and a selection means is provided for selecting the output of these multiple differential displacement detectors.