JPH044996Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a micro material testing machine that determines the properties of materials by applying a micro load. Regarding applied micro material testing machines.

<Conventional technology> By applying a minute load to the surface of the material,
Conventionally, devices that use electromagnetic force have been proposed as loading mechanisms such as microhardness testers that measure the hardness of materials in microscopic regions, and microcompression tests that investigate compressive load-strain characteristics in microscopic regions of the materials. There is.

In the electromagnetic force loading method, an electromagnetic force is generally generated by passing a current through a coil placed in a magnetic field, and this electromagnetic force is used as a load.

<Problem to be solved by the invention> By the way, in such a load mechanism that uses electromagnetic force, it is necessary to control the current flowing through the coil in order to control the magnitude of the load, but this is not possible with a micromaterial testing machine. Since the magnitude of this load is extremely small, it is not easy to control the magnitude of the coil current, and therefore highly accurate load control is difficult, and there are also problems in terms of reproducibility. Also, it was particularly difficult to keep the loading speed constant.

The present invention was developed in view of these points, and has a simple structure that allows for highly accurate control of minute loads on materials, and allows for easy control of the load speed at a constant level. The purpose is to provide material testing equipment.

<Means for solving the problem> In order to achieve the above object, the micromaterial test of the present invention includes a digital signal generation means, a D/A converter for converting the digital signal into an analog, and the D/A converter for converting the digital signal into an analog. a current amplification unit that inputs the output signal of the A converter; and an electromagnetic force generation device that is configured of a coil and a magnet and generates electromagnetic force by passing the output signal of the current amplification unit through the coil; It is characterized by being equipped with an indenter that is attached to the electromagnetic force generator and presses the material using electromagnetic force.

<Effect> The value of the coil current, which determines the magnitude of the load on the material, does not control the current itself;
It is obtained by finally converting an analog voltage obtained by D/A converting a digital value into a current in a current amplification section.

That is, load control can be performed using digital values, and minute loads can be controlled with high precision and good reproducibility.

<Embodiment> The drawing is a block diagram showing the configuration of an embodiment of the present invention.

A material to be tested 2 placed on a sample stage 1 is pressed with an indenter 3 to determine the properties of the material, such as hardness. The load applied by this indenter 3 is minute, ranging from about 0.1 mg to 100 mg or 500 mg.

The load applied to the indenter 3 is applied to a load section (electromagnetic force generating section) consisting of a magnet 8 and a coil 4.
It is determined by the magnitude of the current flowing through the coil 4. The current flowing through this coil 4 is controlled by the following circuit.

The control unit 7 is mainly composed of a microcomputer, and is equipped with a CPU that controls each part, a ROM that stores programs, etc., and a latch device that holds data, and a digital signal that is output to the latch device by the program software. is increased or decreased.

The digital signal from the latch of the control section 7 is converted into an analog signal by the D/A converter 6 and input to the current amplifier 5 as an analog voltage signal.

The current amplifier 5 outputs a current according to the magnitude of the analog voltage signal from the D/A converter 6, and this current flows into the coil 4 of the load section.

With the above configuration, the magnitude of the current flowing through the coil 4, that is, the magnitude of the load on the material under test 2 by the indenter 3, is determined according to the magnitude of the digital signal output from the control section 7. That is,
By controlling the magnitude of the digital value generated by the control unit 7, the load on the material under test 2 is controlled.

Here, when investigating the material properties by pressing the material under test 2 with the indenter 3 at a constant load speed, a clock built in the microcomputer that controls the control section 7 is used, and a predetermined constant clock signal is used based on this clock signal. The digital output may be increased at time intervals, for example using a CPU interrupt.

<Effects of the invention> As explained above, according to the invention, a digital signal is D/A converted to obtain an analog voltage signal, and the analog voltage signal is converted into a current signal by the current amplification section. Therefore, since the current flowing through the coil of the load part is obtained using electromagnetic force, the electromagnetic force is essentially controlled by digital values, and a minute load of about 0.1 mg to several hundred mg can be applied. In addition, it is possible to easily perform highly accurate control even in cases where complex loading conditions are obtained, such as investigation of material properties at a constant loading rate (constant load increase test), and with good reproducibility.

[Brief explanation of the drawing]

The drawing is a block diagram showing the configuration of an embodiment of the present invention. 1...Sample stage, 2...Test material, 3...Indenter, 4...Coil, 5...Current amplification unit, 6...
D/A converter, 7...control unit, 8...magnet.

Claims (1)

[Claims for Utility Model Registration] (1) In a testing machine that determines the characteristics of a material by applying a minute load to the material, means for generating a digital signal and a D/A conversion for converting the digital signal into an analogue. an electromagnetic force that generates an electromagnetic force by passing the output signal of the current amplifier through the coil, a current amplifier that inputs the output signal of the D/A converter, a coil, and a magnet. A micromaterial testing machine characterized by comprising a generator and an indenter attached to the electromagnetic force generator to press a material using electromagnetic force. (2) Claim 1 of the Utility Model Registration Claim characterized in that the digital signal generating means is configured to generate a digital signal whose value increases at regular time intervals based on the reference clock output. micro material testing machine.