JPH0532752Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a load verification mechanism for a hardness tester used to measure the hardness of a thin film formed on the surface of a test object.

[Prior art] There are various testing machines such as Micro Vickers hardness testers that measure the hardness of the sample by pressing an indenter against the sample surface with a predetermined load and measuring the depth, size, etc. of the resulting indentation. . In these devices, the hardness of a sample is determined based on the area, depth, etc. of an indentation caused by pressing with an indenter. Conventionally, the load amount, which is the most important test for hardness measurement, has been carried out by placing a sample on a precision balance, pressing an indenter against the sample, and checking the load applied to the sample using the balance.

[Problems to be solved by the invention] However, the load verification using the above method requires a highly accurate balance, and the operations such as placing the precision balance below the indenter are complicated. Another problem was that users of hardness meters rarely actually perform load verification. Therefore, an object of the present invention is to provide a load verification mechanism that can perform load verification of a hardness tester with a simple operation.

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

In other words, the hardness tester load verification mechanism according to the present invention includes a variable load means that can arbitrarily change the load by changing the amount of current, and a load of the load means or a test weight. an indenter that is pushed into the sample surface by the indenter, a displacement detection means for detecting the amount of displacement of the indenter, a means for calculating a load acting on the indenter from the amount of current supplied to the variable load means, and the verification. The displacement of the indenter obtained when a current is supplied to the loading means so as to output a load equivalent to the weight of the test weight is compared with the displacement of the indenter when the test weight is actually loaded, and the two are compared. The present invention is characterized by comprising calculation means for calculating the difference between the actual load of the load means and the weight of the verification weight from the increase/decrease in the current supplied to the load means necessary for making them match.

[Function] When a load current corresponding to the acting force equivalent to the test weight load is supplied to the load means, the indenter is displaced,
The displacement D _O at this time is detected by the displacement amount detection means. Next, a test weight with a weight of L _O is placed on the weight receiver provided on the top of the indenter, and the displacement at this time is
D ₁ is detected by the displacement amount detection means.

Next, by adjusting the amount of current flowing through the load means, the displacement D ₁ when the test weight is placed and the displacement
The current value required for this is calculated as _the acting force by the calculation means, and the
Load accuracy is calculated based on L _O and the acting force.

[Example] FIG. 1 is a sectional view of an ultra-microhardness tester equipped with a load verification mechanism of the present invention, in which a loading device (loading means) 1 in a frame 20 is connected to one side of a balanced balance 2. It is constructed as a self-balancing electronic balance type with an indenter 6 attached to one end and an electromagnetic coil 3 attached to the other end. That is, a direct current is passed through the electromagnetic coil 3 from the measurement control device 12, and depending on whether the direction of the current is flowing is positive or reverse, a load is added or decreased by the electromagnetic force of the electromagnetic coil 3, and the load is applied to the stage 9 of the sample stage 8 via the indenter 6. The load on the sample 7 placed above can be increased or decreased. That is, the above-mentioned load is brought about by the electromagnetic force induced by the electromagnetic coil 3 in accordance with the amount of current, and drives the indenter 6. A weight receiver 21 on which a load verification weight can be placed is provided above the indenter 6.

The details of the load verification operation are as follows. A differential transformer-type displacement detector provided above the indenter 6 detects the displacement _DO brought to the indenter when a load current that produces an acting force equivalent to the weight of the load verification weight is passed through the electromagnetic coil 3. 5 and stored in a storage device provided within the control device 12. Next, the load verification weight 22 is placed on the weight receiver 21, and the weight of the weight is
L _O is stored in the storage device. The displacement D ₁ of the indenter at this time is grasped as the output of the displacement detector 5 in the same manner as described above. This displacement D ₁ is supposed to match the actual indenter displacement D _O caused by a load current that produces an acting force equivalent to the weight of the test weight, but in reality the two are usually different. be. Therefore, by adjusting the current value applied to the electromagnetic coil 3 while reading the output of the displacement detector 5, the indenter is moved up and down to make the output match D _O. The acting force difference F with the test weight load is calculated based on the amount of current required to make the displacement D ₁ match the displacement D _O at this time, and then the load accuracy R given by the following formula is calculated in the control device 12. It is calculated by the means and displayed by the surface instrument.

R=(L _O −F)/L _O ×100 The force acting on the indenter caused by energizing the electromagnetic coil 3 is determined according to the current value as described above,
There is a proportional relationship between the two as shown in the following equation.

F=k・I (I: current value k: constant) In other words, as mentioned above, when the test weight 22 is placed on the weight receiver 21, a current amount equivalent to the displacement D ₁ of the indenter and the weight load is applied. The load verification is performed based on the fact that the displacements in the case should be the same in an ideal state. Note that the amount of displacement detected by the displacement detector 5, that is, the amount of displacement detected by the indenter 6
The amount of movement is quantitatively captured by a displacement measuring device (amplifier) 10 and sent to the measurement control device 12 as displacement information. In the illustrated example, the displacement measuring tool 1
0 is built into the measurement control device 12. The load generated by the loading device 1 is already applied to the measurement control device 1.
2, the displacement under a certain load can be measured in real time. The control device 12 performs arithmetic processing based on the obtained data and sends the necessary processing results to a recording device 13 such as a recorder.
Output to.

In addition to the main components as the tester described above, the example device includes an optical monitor 15 as an auxiliary device.
is provided. The optical monitor 15 includes an objective lens 17 and an eyepiece lens 16, and is used by an operator to measure the position on the surface of the sample 7 to be tested and to observe the state of the depression formed by the indenter 6. be. A stage 9 that can be raised and lowered is detachably provided on the sample table 8, and a vice for fixing the sample 7 is attached to the upper surface of the stage 9. By operating the sample stage 8, the indenter 6 and sample 7 can be brought closer together or moved to an arbitrary test position.

In the above embodiment, an example is shown in which a differential transformer type is used as the indenter displacement detecting means, but it is not limited to the differential transformer type, and other types may be used.

[Effect of the invention] As is clear from the above explanation, the load verification mechanism of the hardness tester according to the invention is based on the difference between the load based on the verification weight and the acting force determined in accordance with the amount of current flowing through the load means. Since the load accuracy of the force exerted by the load means is required, it has become possible to perform load verification with a simple operation, and it has become possible to accurately measure hardness values.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a hardness meter incorporating the load verification mechanism of the present invention, and FIG. 2 is a flowchart showing the operation of the mechanism. DESCRIPTION OF SYMBOLS 1... Loading device, 5... Displacement detector, 6... Indenter, 7... Sample, 12... Measurement control device, 13...
... Recording device, 21 ... Weight holder, 22 ... Test weight.

Claims (1)

[Scope of utility model registration request] A variable load means that can arbitrarily change the load by changing the amount of current, an indenter that is pushed into the sample surface when the load of the load means or the load of a test weight is applied, and the indenter. displacement detection means for detecting the displacement of the indenter; means for calculating the load acting on the indenter from the amount of current supplied to the variable load means; and means for outputting a load corresponding to the weight of the verification weight. Compare the displacement of the indenter obtained when a current is supplied to the load means with the displacement of the indenter when a test weight is actually loaded, and calculate the amount of current supplied to the load means necessary to make the two match. A load verification mechanism for a hardness tester, comprising a calculation means for calculating the difference between the actual load of the load means and the weight of a verification weight from an increase/decrease.