JP6033702B2 - Hardness tester and constant pressure unit mechanism - Google Patents

Description

  The present invention relates to a hardness tester and a constant pressure unit mechanism provided in the hardness tester.

2. Description of the Related Art Conventionally, a hardness tester that measures the hardness of a sample by applying a test force to the surface of the sample using an indenter and forming a recess is known.
As a hardness tester as described above, when the indenter is pressed against the sample with a predetermined test force, the depth at which the indenter is pushed into the sample and enters (the depth of the indentation formed on the sample by the indenter) is measured. A Rockwell hardness tester that calculates hardness based on the measured indentation depth is known.
Also known is a Vickers hardness tester that measures the length of a diagonal line of a depression formed by pressing an indenter against a sample with a predetermined test force, and calculates the hardness based on the measured diagonal length. Yes.

Also, hardness tests with different test methods, ie, a test for calculating hardness based on indentation depth (eg, Rockwell hardness test) and a test for calculating hardness based on indentation dimensions (eg, Vickers) A hardness tester capable of performing both of (hardness test) and a single machine is known (see, for example, Patent Documents 1 and 2).
Also, a hardness tester that is a test for calculating the hardness based on the indentation depth and that can accurately perform the instrumented indentation test defined in ISO14577 is known (for example, Patent Document 3). reference).

Japanese Patent No. 3934491 Japanese Patent No. 3875639 Japanese Patent No. 5017081

However, a hardness tester that can perform the above-described three tests with one unit has not been realized. When performing an instrumented indentation test in the hardness tester described in Patent Documents 1 and 2 above, it is strongly affected by machine frame distortion and temperature drift of the machine frame and the sample, so the test cannot be performed with high accuracy. There is a problem.
On the other hand, in the hardness tester described in Patent Document 3, a hardness test (for example, instrumentation indentation) with a different test method including an instrumentation indentation test is performed by attaching a device for measuring the size of the formed indentation. Test and Vickers hardness test) can be performed, but there is a problem that it is expensive.

  It is an object of the present invention to provide a hardness tester that can perform hardness tests with different test methods including an instrumented indentation test and is inexpensive, and a constant pressure unit mechanism provided in the hardness tester. Objective.

The invention described in claim 1 has been made to achieve the above object,
With an indenter,
A test force loading means for applying a test force to the indenter and pushing the indenter into a surface of a sample;
An intrusion amount detecting means for detecting an intrusion amount of the indenter pushed into the surface of the sample by the test force loading means;
Indentation size detecting means for detecting the size of an indentation formed by pushing the indenter into the surface of the sample by the test force loading means;
First hardness calculation means for calculating the hardness of the sample based on the intrusion amount of the indenter detected by the intrusion amount detection means;
Second hardness calculating means for calculating the hardness of the sample based on the size of the recess detected by the recess size detecting means;
A reference portion having a reference surface when the intrusion amount detecting means detects the intrusion amount of the indenter;
A constant pressure unit having a sample holding part capable of holding the sample, and pressing the sample or the sample holding part at a constant pressure against a reference surface of the reference part;
An elevating device that moves the constant pressure unit in the up and down direction,
The constant pressure unit is
A support part that has an upper restricting part that restricts the upward movement of the sample holding part, and supports the sample holding part so as to be movable in the vertical direction;
An elastic member that urges the sample and the sample holding portion upward, and
When the sample or the sample holding part is pressed against the reference surface of the reference part by being moved upward by the lifting device, a vertical gap is generated between the sample holding part and the upper restricting part. It is characterized by being formed.

The invention according to claim 2 is the hardness tester according to claim 1,
The sample holder is capable of placing the sample on the upper surface,
The elastic member urges the sample holder from the lower surface side,
The sample is pressed against the reference surface of the reference portion with a constant pressure.

The invention according to claim 3 is the hardness tester according to claim 1,
The sample holder is
A storage section for storing the sample movably in the vertical direction;
A sample restricting portion that is provided at an upper end of the storage portion and restricts the upward movement of the sample;
The elastic member urges the sample from the lower surface side,
The sample is pressed against the reference surface of the reference portion with a constant pressure.

The invention according to claim 4 is the hardness tester according to claim 1,
The sample holder is
A storage section for storing the sample movably in the vertical direction;
A sample restricting portion that is provided at an upper end of the storage portion and restricts the upward movement of the sample;
The elastic member urges the sample from the lower surface side,
The sample restricting portion is pressed against the reference surface of the reference portion with a constant pressure.

The invention according to claim 5 is the hardness tester according to claim 1,
The sample holder is capable of placing the sample on the upper surface,
The elastic member supports the sample holder from the side and urges it upward,
The sample is pressed against the reference surface of the reference portion with a constant pressure.

The invention according to claim 6 is a constant pressure unit mechanism,
A reference portion having a reference surface for detecting the indentation amount of the indenter;
A sample holding unit capable of holding a sample, and a constant pressure unit that presses the sample or the sample holding unit to a reference surface of the reference unit with a constant pressure,
The constant pressure unit is
A support part that has an upper restricting part that restricts the upward movement of the sample holding part, and supports the sample holding part so as to be movable in the vertical direction;
An elastic member that urges the sample and the sample holding portion upward, and
When the sample or the sample holding part is pressed against the reference surface of the reference part, a vertical gap is formed between the sample holding part and the upper restricting part. To do.

  According to the present invention, it is possible to perform a test for calculating the hardness based on the size of the recess. Also, during the indentation test, the sample or sample holder is pressed against the reference surface of the reference part, and the indentation depth measurement reference is the surface of the sample. The influence of can be eliminated. Also, during the indentation test, there is a gap between the sample holding part and the upper restriction part of the support part, and the rigidity of the elastic member is sufficiently smaller than the test machine body and the reference part, so the sample, sample holding part, test machine body Even when a portion related to a force path such as this is expanded or contracted due to temperature fluctuation, the force pressing the sample against the reference surface of the reference portion becomes a constant pressure, and the stability of the indentation depth measurement can be maintained. Therefore, it is possible to provide a hardness tester that can perform hardness tests with different test methods including an instrumented indentation test and is inexpensive.

It is a right view which shows the whole structure of the hardness tester based on this invention. It is a right view which shows an example which rotated the turret and has arrange | positioned the objective lens above the sample. It is a block diagram which shows the control structure of the hardness tester which concerns on this invention. It is a right view which shows an example which pressed the sample against the indentation depth measurement reference | standard part. It is a right view which shows one modification of a constant pressure unit. It is a right view which shows one modification of the indentation depth measurement reference | standard part. It is a right view which shows one modification of a constant pressure unit.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the X direction in the figure is the left-right direction, the Y direction is the front-rear direction, and the Z direction is the up-down direction. The XY plane is a horizontal plane.

  The hardness tester 1 is, for example, a Vickers hardness tester in which the planar shape of the indenter 4a is formed in a rectangular shape, and as shown in FIGS. 1 to 4, a load arm 2, a test force generator 3, , An indenter shaft 4 having an indenter 4a at the tip, an objective lens 5, a turret 6, an indenter shaft displacement detector 7, a sample stage 8, a stage elevating unit 9, a constant pressure unit 10, and an imaging unit 20. , Etc. are provided. In the hardness tester 1, operation control of each unit is performed by the control unit 100 shown in FIG.

The load arm 2 is pivotally supported on the testing machine main body 1 a of the hardness testing machine 1 by a rotating shaft 21 at its front end. A load shaft 22 that is elastically supported by an elastic member such as a coil spring is provided on the lower surface side of the load arm 2.
A first force motor 31 that generates an electromagnetic force that operates the load arm 2 is connected to the rear end of the load arm 2. The load arm 2 rotates clockwise around the rotation shaft 21 in accordance with the operation of the first force motor 31. Along with the downward rotation of the load arm 2, a predetermined load acts on the indenter shaft 4 via the load shaft 22, and the indenter shaft 4 moves in the lower axis direction. Then, the indenter 4 a provided at the tip of the indenter shaft 4 is pressed against the sample S with a predetermined test force.
That is, the load arm 2 has a function of transmitting a predetermined test force to the indenter 4a.

The test force generator 3 is provided at the rear end of the load arm 2 and rotates the load arm 2 by electromagnetic force to apply a predetermined test force (first test force) to the indenter 4a. 31 and an upper end portion of the indenter shaft 4, and the indenter shaft 4 is moved downward by an electromagnetic force to apply a predetermined test force (second test force smaller than the first test force) to the indenter 4a. And a second force motor 32 to be loaded.
The first force motor 31 and the second force motor 32 include, for example, a force coil, a fixed magnet fixed so as to face the force coil, and the like. The first force motor 31 and the second force motor 32 are electromagnetic inductions of a magnetic field generated by a fixed magnet in a gap and a current flowing in a force coil installed in the gap according to a control signal input from the control unit 100. The force generated by (electromagnetic force) is generated.
Then, the first force motor 31 rotates the load arm 2 by the generated electromagnetic force to apply a test force to the indenter 4 a and pushes the indenter 4 a into the surface of the sample S. That is, the first force motor 31 functions as the test force loading means of the present invention.

The indenter shaft 4 is moved toward the sample S placed on the sample stage 11 provided below by the operation of the test force generation unit 3, and the indenter 4 a provided at the tip is provided on the surface of the sample S. Press with the test force. A depression is formed on the surface of the sample S when the indenter 4a presses the sample S with a predetermined test force.
As the indenter 4a, for example, a Vickers quadrangular pyramid indenter (face-to-face angle is 136 ± 0.5 °), an indenter for an instrumented indentation test, or the like can be used. Can do.

  The objective lens 5 is a lens unit associated with the imaging unit 20 and is held on the lower surface of the turret 6. As shown in FIG. 2, the objective lens 5 can image the sample S by the imaging unit 20 when the turret 6 (turret body 61) is rotated and the objective lens 5 is switched to an arrangement corresponding to the imaging unit 20. And

  The turret 6 is configured such that the indenter shaft 4 and the objective lens 5 can be attached to the lower surface thereof, and is rotatably supported on the testing machine main body 1a by a rotating shaft 6a. The indenter shaft 4 is attached to the turret 6 via an indenter shaft holding portion 41. The turret 6 is configured such that any one of the indenter shaft 4 and the objective lens 5 can be disposed above the sample S by rotating around the rotation shaft 6a. That is, for example, a depression can be formed on the surface of the sample S by arranging the indenter shaft 4 above the sample S, and the depression formed by arranging the objective lens 5 above the sample S is observed. Be able to.

The indenter shaft holding portion 41 includes an indenter shaft base 41a, an indenter shaft guide 41b provided on the indenter shaft base 41a along the indenter shaft 4, and a plate spring 41c extending in a horizontal direction from the indenter shaft guide 41b. , And is configured. The indenter shaft 4 is elastically supported by a leaf spring 41 c and is perpendicular to the mounting surface of the sample S of the sample table 11, particularly the surface (upper surface) of the sample S mounted on the sample table 11. Is provided. Further, on the lower surface of the indenter shaft base 41a, an indentation depth measurement reference portion 71 is attached as a reference portion having a reference surface when the indenter shaft displacement detection portion 7 detects the intrusion amount of the indenter 4a.
1, the turret 6 (turret body 61) is rotated to switch the indenter shaft 4 to an arrangement corresponding to the load shaft 22, whereby the load shaft 22 moves downward as the load arm 2 rotates. The acting force of the moving operation can be transmitted to the indenter shaft 4. As a result, the indenter 4a can be pressed against the sample S and pushed.

An indenter shaft displacement detector 7 that detects the amount of displacement of the indenter shaft 4 is provided on the indenter shaft base 41a.
The indenter shaft displacement detection unit 7 includes, for example, a scale on which a graduation with a predetermined interval is engraved and a linear encoder that optically reads the scale graduation, and the indenter shaft 4 when the indenter 4 a is pushed into the sample S. Displacement amount (that is, the intrusion amount (indentation depth) of the indenter 4a pushed into the sample S) is detected, and an indenter shaft displacement signal based on the detected displacement amount is output to the control unit 100.
In other words, the indenter shaft displacement detector 7 functions as an intrusion amount detecting means for detecting the intrusion amount of the indenter 4a pushed into the surface of the sample S.

The indentation depth measurement reference portion 71 is a member that is attached to the lower surface of the indenter shaft base 41 a and serves as a vertical position reference for the tip portion of the indenter 4 a provided at the tip portion of the indenter shaft 4. The indentation depth measurement reference portion 71 includes a hole portion 71a through which the indenter 4a can be inserted at the center, and has a donut shape when viewed from the bottom. Further, in the vicinity of the hole 71 a on the lower surface of the indentation depth measurement reference portion 71, a sample surface contact portion 71 b protruding downward is provided. The lower surface of the sample surface contact portion 71b is formed to be a surface (horizontal plane) perpendicular to the indenter shaft 4. Then, an indentation test is performed in a state where the lower surface of the sample surface contact portion 71b is in contact with the surface of the sample S, whereby the indenter shaft displacement is detected using the lower surface of the sample surface contact portion 71b (the surface of the sample S) as a reference surface. The intrusion amount of the indenter 4a can be detected by the unit 7.
The indentation depth measurement reference portion 71 is detachably attached with a screw or the like so that it can be removed when the indenter 4a is replaced or when a Vickers hardness test is performed.

The sample stage 8 is disposed so as to face the turret 6 and is configured such that the constant pressure unit 10 can be placed on the upper surface. The sample stage 8 is, for example, an XY stage that can move on a horizontal plane, and is driven by a drive mechanism unit (not shown) that is driven in accordance with a control signal output by the control unit 100 to move the constant pressure unit 10 through the indenter 4a. Move in a direction (horizontal direction) perpendicular to the direction (vertical direction). In the present embodiment, for example, when performing the Vickers hardness test, the sample S may be directly placed on the sample stage 8 without placing the constant pressure unit 10 on the sample stage 8.
The stage lifting / lowering unit (up / down device) 9 is provided on the lower surface side of the sample stage 8 and is driven according to a control signal output from the control unit 100 to move the sample stage 8 and the constant pressure unit 10 in the vertical direction.

The constant pressure unit 10 includes a sample table 11 as a sample holding unit capable of holding the sample S, a constant pressure unit case 12 as a sample holding unit support unit that supports the sample table 11 so as to be movable in the vertical direction, and a sample table guide 13. And a holding spring 14 as an elastic member for urging the sample S upward.
The sample stage 11 is formed of a substantially prismatic member, and the sample S can be placed on the upper surface. Further, the sample stage 11 has a recess 11a formed on the lower end side.
The constant pressure unit case 12 is placed on the upper surface of the sample stage 8 and supports the sample table 11 from the side so as to be movable in the vertical direction via a sample table guide 13 that functions as a roll. In addition, the constant pressure unit case 12 supports the sample table 11 from the lower surface side via a holding spring 14 accommodated in the recess 11 a of the sample table 11. Further, an upper restricting portion (sample holding portion restricting portion) 12 a that restricts the upward movement of the sample stage 11 is provided at the upper end portion of the constant pressure unit case 12.
The holding spring 14 biases the sample stage 11 from the lower surface side with a force larger than the test force loaded from above. The rigidity of the holding spring 14 is sufficiently smaller than that of the testing machine main body 1a and the indentation depth measurement reference portion 71.
That is, in the normal pressure unit 10, as shown in FIGS. 1 and 2, the shoulder portion 11b of the sample table 11 is pressed against the upper regulating portion 12a of the constant pressure unit case 12 by the urging force of the holding spring 14. It is in a state. Further, the constant pressure unit 10 presses the sample S at a constant pressure by the urging force of the pressing spring 14 when the sample S is pressed against the lower surface of the sample surface contact part 71 b of the pressing depth measurement reference part 71 by the stage elevating part 9.

  The imaging unit 20 includes a microscope unit 20a, a CCD camera 20b (see FIG. 3) attached to the microscope unit 20a, an illumination device (not shown) that illuminates the observation position of the sample S, and the like. The hollow formed on the surface of the sample S on the constant pressure unit 10 is imaged. Then, the imaging unit 20 (CCD camera 20b) outputs the captured image data of the depression to the control unit 100.

As shown in FIG. 3, the control unit 100 includes a CPU 101, a RAM 102, and a storage unit 103. The control unit 100 has a predetermined hardness by executing a predetermined program stored in the storage unit 103. It has a function of performing operation control and the like for performing tests.
The CPU 101 reads the processing program stored in the storage unit 103, develops it in the RAM 102, and executes it to control the entire hardness tester 1.
The RAM 102 develops a processing program executed by the CPU 101 in a program storage area in the RAM 102, and stores input data and a processing result generated when the processing program is executed in the data storage area.
The storage unit 103 includes, for example, a recording medium (not shown) that stores programs, data, and the like, and this recording medium is configured by a semiconductor memory or the like. In addition, the storage unit 103 stores various data, various processing programs, data processed by the execution of these programs, and the like for realizing a function for the CPU 101 to control the entire hardness tester 1.

  For example, the CPU 101 applies control signals for controlling the driving of the first force motor 31 and the second force motor 32 to cause the indenter 4a to act on the sample S with a predetermined test force (load). Output to the force motor 32.

  In addition, the CPU 101 calculates the hardness of the sample S based on the indenter shaft displacement signal input from the indenter shaft displacement detector 7 as a first hardness calculation unit. Specifically, the first hardness calculation means measures the hardness of the sample S based on the intrusion amount (indentation depth) of the indenter 4a pushed into the sample S.

  Further, the CPU 101 detects the size of the recess formed by the indenter 4a being pushed into the surface of the sample S as the recess size detecting means. Specifically, the indentation size detecting means analyzes the indentation image data by performing predetermined image processing on the indentation image data input from the imaging unit 20, and automatically measures the indentation size. The length of the diagonal of is calculated.

  Further, the CPU 101 calculates the hardness of the sample S based on the size of the dent detected by the dent size detection unit as the second hardness calculation unit. Specifically, the second hardness calculation means measures the hardness of the sample S based on the length of the diagonal line of the depression formed by the indenter 4a being pushed into the surface of the sample S.

Next, the operation | movement at the time of performing the hardness test in the hardness tester 1 which concerns on this embodiment is demonstrated.
First, the operation during the instrumentation indentation test will be described.

First, an indenter 4a for instrumentation indentation test is attached to the indenter shaft 4, and an indentation depth measurement reference portion 71 is attached to the lower surface of the indenter shaft base 41a.
Next, the constant pressure unit 10 is attached to the upper surface of the sample stage 8, and the sample S is placed on the sample stage 11 of the constant pressure unit 10.
Next, the turret 6 is rotated to place the objective lens 5 above the sample S, and the stage elevating unit 9 is driven to focus. Next, the surface of the sample S is observed by the imaging unit 10, and the sample stage 8 is driven to be arranged at a desired test position.
Next, the turret 6 is rotated to place the indenter shaft 4 above the sample S (below the load shaft 22) (see FIG. 1).
Next, the stage elevating unit 9 is driven and raised, and the sample S is pressed against the lower surface (reference surface) of the sample surface contact portion 71 b of the indentation depth measurement reference portion 71. As a result, even when the sample S expands and contracts due to temperature fluctuations, the expansion and contraction can be automatically adjusted by the driving amount of the stage elevating unit 9, so that the force pressing the sample S against the reference surface is constant pressure. can do. Then, the stage elevating unit 9 is further driven to raise, and a gap P1 is generated between the sample stage 11 whose rise is restricted by the sample surface contact part 71b and the upper regulating part 12a of the rising constant pressure unit case 12. (See FIG. 4). At this time, the upper surface of the sample stage 11 and the upper surface of the constant pressure unit case 12 are substantially flush with each other. That is, the constant pressure unit 10 is moved upward by the stage elevating unit 9 and when the sample S is pressed against the lower surface of the sample surface contact part 71b of the indentation depth measurement reference part 71, the sample stage 11 and the upper restriction part 12a. The gap P1 in the vertical direction is formed between the two.
Next, the control unit 100 drives the first force motor 31 to rotate the load arm 2 downward. As the load arm 2 rotates downward, the load shaft 22 is pressed and moved downward, and the indenter shaft 4 that contacts the load shaft 22 moves downward. Then, the indenter 4a provided at the tip of the indenter shaft 4 is pushed into the sample S with a predetermined test force. Further, when it is desired to finely adjust the test force, the control unit 100 drives the second force motor 32 to apply a small test force to the indenter shaft 4.
Next, a displacement amount (indentation depth) of the indenter shaft 6 when the indenter 5 forms a recess in the sample S is detected by the indenter shaft displacement detection unit 20, and the indenter shaft displacement based on the detected displacement amount is detected. A signal is output to the control unit 100. Then, the control unit 100 calculates the hardness of the sample S and various material characteristics based on the input indenter shaft displacement signal.
When performing the indentation test continuously, the stage elevating unit 9 is driven and lowered to cancel the contact state between the indentation depth measurement reference unit 71 and the sample S.
Then, the turret 6 is rotated to place the objective lens 5 above the sample S, and the stage elevating unit 9 is driven to focus. Next, the surface of the sample S is observed by the imaging unit 10, and the sample stage 8 is driven to be arranged at a desired test position. Thereafter, the indentation test is performed at all desired test positions by repeating the above process.

Next, the operation during the Vickers hardness test will be described.
First, an indenter 4 a for Vickers hardness test is attached to the indenter shaft 4. Next, the sample S is placed on the sample stage 8. In this description, it is assumed that the constant pressure unit 10 is not placed on the sample stage 8 but the sample S is placed directly.
Next, the turret 6 is rotated to place the objective lens 5 above the sample S, and the stage elevating unit 9 is driven to focus. Next, the surface of the sample S is observed by the imaging unit 10, and the sample stage 8 is driven to be arranged at a desired test position.
Next, the turret 6 is rotated to place the indenter shaft 4 above the sample S (below the load shaft 22).
Next, the control unit 100 drives the first force motor 31 to rotate the load arm 2 downward. As the load arm 2 rotates downward, the load shaft 22 is pressed and moved downward, and the indenter shaft 4 that contacts the load shaft 22 moves downward. Then, the indenter 4a provided at the distal end portion of the indenter shaft 4 is pushed into the sample S with a predetermined test force to form a recess. Further, when it is desired to finely adjust the test force, the control unit 100 drives the second force motor 32 to apply a small test force to the indenter shaft 4.
Next, the turret 6 is rotated to place the objective lens 5 above the sample S, and the stage elevating unit 9 is driven to focus. Next, the surface of the sample S is imaged by the imaging unit 10, and the image data of the depression formed in the sample S is output to the control unit 100. Then, the control unit 100 analyzes the input image data, calculates the diagonal length of the substantially rectangular depression formed by the indenter 4a for Vickers hardness test, and based on the calculated diagonal length Thus, the hardness of the sample S is calculated.

As described above, the hardness tester 1 according to the present embodiment loads the test force on the indenter 4 a and pushes the indenter 4 a into the surface of the sample S, and the sample S by the first force motor 31. An indenter shaft displacement detector 7 for detecting the amount of intrusion of the indenter 4a pushed into the surface of the dent, and a recess size for detecting the size of the dent formed by the indenter 4a being pushed into the surface of the sample S by the first force motor 31. The detection means (CPU 61), the first hardness calculation means (CPU 61) for calculating the hardness of the sample S based on the intrusion amount of the indenter 4a detected by the indenter shaft displacement detection unit 7, and the indentation size detection means Second hardness calculation means (CPU 61) for calculating the hardness of the sample S based on the detected size of the indentation, and a reference surface when the indenter shaft displacement detection unit 7 detects the intrusion amount of the indenter 4a. Indentation A constant pressure unit 10 having a thickness measurement reference portion 71 and a sample stage 11 capable of holding the sample S, and pressing the sample S at a constant pressure against the reference surface of the indentation depth measurement reference portion 71 (the lower surface of the sample surface contact portion 71b); And a stage elevating unit 9 for moving the constant pressure unit 10 in the vertical direction. Further, in the hardness tester 1, the constant pressure unit 10 has an upper restricting portion 12a that restricts the upward movement of the sample stage 11, and a constant pressure unit case 12 that supports the sample stage 11 so as to be movable in the vertical direction. And a holding spring 14 that urges the sample S upward, and is moved upward by the stage elevating unit 9 and the sample S is pressed against the reference surface of the indentation depth measurement reference unit 71. 11 and the upper restricting portion 12a are formed such that a vertical gap P1 is generated.
Therefore, according to the hardness testing machine 1 which concerns on this embodiment, the test (for example, Vickers hardness test) which calculates hardness based on the length of a hollow can be performed. In addition, during the indentation test, the sample S is pressed against the reference surface of the indentation depth measurement reference unit 71, and the indentation depth measurement reference is the surface of the sample S. The influence of the hysteresis of the frame can be eliminated. Further, during the indentation test, there is a gap P1 between the sample table 11 and the upper regulating portion 12a of the constant pressure unit case 12, and the rigidity of the retaining spring 14 is sufficiently smaller than that of the testing machine main body 1a and the indentation depth measurement reference portion 71. Therefore, even when the portion related to the force path such as the sample S, the sample stage 11 and the testing machine main body 1a expands and contracts due to temperature fluctuation, the force pressing the sample S against the reference surface of the indentation depth measurement reference portion 71 is large. The pressure becomes constant and the stability of the indentation depth measurement can be maintained. Therefore, it is possible to provide a hardness tester that can perform hardness tests with different test methods including an instrumented indentation test and is inexpensive.

  As mentioned above, although concretely demonstrated based on embodiment which concerns on this invention, this invention is not limited to the said embodiment, It can change in the range which does not deviate from the summary.

(Modification 1)
For example, in the example illustrated in FIG. 5, the configuration of the sample S and the configuration of the constant pressure unit 10 are different from those in the embodiment. For simplification of description, the same reference numerals are given to the same configurations as those in the embodiment, and detailed description thereof is omitted.
Specifically, in the example shown in FIG. 5, a resin-embedded sample S1 in which a metal sample piece S12 is embedded in a resin material S11 is used as a sample. The resin-embedded sample S1 is formed so that the horizontal width of the sample piece S12 is equal to or larger than the horizontal width of the sample surface contact portion 71b.
The constant pressure unit 10 </ b> A according to Modification 1 includes a sample holder 15 as a sample holder that can hold the sample S, a constant pressure unit case 12, a sample stage guide 13, and a pressing spring 14. .
The sample holder 15 includes a storage portion 151 that stores the resin-embedded sample S1 and the pressing spring 14 placed on the lower surface side of the resin-embedded sample S1. The sample holder 15 is supported from the outside (side) by the constant pressure unit case 12 via the sample table guide 13 so as to be movable in the vertical direction. In addition, the upper end of the storage portion 151 of the sample holder 15 is locked by the constant pressure unit case 12 through the holding spring 14 from the lower surface side to the upper surface side of the resin-embedded sample S1 to restrict upward movement. A sample restricting portion 15a is provided.
As shown in FIG. 5, the constant pressure unit 10 </ b> A normally has the shoulder 15 b of the sample holder 15 to be connected to the upper regulating portion 12 a of the constant pressure unit case 12 through the resin-embedded sample S <b> 1 by the biasing force of the holding spring 14. It is in a pressed state. Then, as in the embodiment, the stage elevating unit 9 is driven and raised, and the sample piece S12 of the resin-embedded sample S1 is pressed against the lower surface (reference surface) of the sample surface contact part 71b of the indentation depth measurement reference part 71, A gap P1 is generated between the sample holder 15 whose rise is restricted by the surface contact portion 71b and the constant pressure unit case 12 that rises.

  As described above, the constant pressure unit 10A of the hardness tester 1 according to the modified example 1 includes the sample restricting portion 15a that restricts the upward movement of the resin-embedded sample S1, and supports the resin-embedded sample S1 from the side. And a pressing spring 14 that urges the resin-embedded sample S1 upward from the lower surface side, and presses the resin-embedded sample S1 against the reference surface of the indentation depth measurement reference portion 71 with a constant pressure. Therefore, according to the hardness tester 1 according to the modified example 1, the resin-embedded sample S1 can be pushed upward by the urging force of the pressing spring 14 even when the resin material S11 expands and contracts due to temperature fluctuation. Therefore, the force for pressing the resin-embedded sample S1 against the reference surface of the indentation depth measurement reference portion 71 becomes a constant pressure, and the indentation depth measurement stability can be maintained.

(Modification 2)
In the example shown in FIG. 6, the shape of the indentation depth measurement reference portion 71 is different from that in the first modification. For simplification of description, the same reference numerals are given to the same configurations as those in the embodiment and the first modification, and detailed description thereof is omitted.
Specifically, the indentation depth measurement reference portion 72 according to the second modification is more horizontal than the sample surface contact portion 71b of the indentation depth measurement reference portion 71 according to the embodiment and the first modification. The width in the direction is formed to be wide.
Therefore, when the indentation test is performed by the hardness tester 1 according to the modified example 2, the lower surface (reference surface) of the sample surface contact portion 72b is not the surface of the resin-embedded sample S1, but the sample regulating portion 15a of the sample holder 15 It will come into contact. That is, according to the hardness tester 1 according to the modified example 2, the constant pressure unit 10A presses the sample restricting portion 15a against the reference surface with a constant pressure, so that the reference surface does not come into direct contact with the resin-embedded sample S1. It is possible to perform an indentation test even on the resin-embedded sample S1 having unevenness.

(Modification 3)
Moreover, in the example shown in FIG. 7, the structure of the constant pressure unit 10 differs compared with embodiment. For simplification of description, the same reference numerals are given to the same configurations as those in the embodiment, and detailed description thereof is omitted.
Specifically, the constant pressure unit 10B according to Modification 3 includes a sample stage 11B and a constant pressure unit case 12B.
The sample stage 11B is formed of a substantially rectangular plate-like member so that the sample S can be placed on the upper surface. In addition, a protrusion 111B that protrudes in the horizontal direction from the lower end is formed on the peripheral end surface of the sample stage 11B.
The constant pressure unit case 12B includes a lower end 121B placed on the sample stage 8, a spring support 122B placed on the upper surface of the lower end 121B, one end fixed to the spring support 122B, and the other end. Includes a diaphragm spring 123B as an elastic member fixed to the sample stage 11B, and an upper restricting portion 124B placed on the upper surface of the spring support portion 122B. Here, the diaphragm spring 123B supports the sample stage 11B from the side and biases it upward.
As shown in FIG. 7A, the constant pressure unit 10B normally has a state in which the protrusion 111B of the sample stage 11B is pressed against the upper restriction portion 124B of the constant pressure unit case 12B by the biasing force of the diaphragm spring 123B. It has become. Then, similarly to the embodiment, the stage elevating unit 9 is driven to be raised, and the lower surface (reference surface) of the sample surface contact part 71b of the indentation depth measurement reference part 71 as shown in FIG. And a gap P2 is generated between the sample stage 11B whose rise is restricted by the sample surface contact portion 71b and the constant pressure unit case 12B that rises.
Therefore, according to the hardness tester 1 according to the modified example 3, since the sample stand 11B is provided from the side and supported by the diaphragm spring 123B for urging upward, the sample stand 11B is not from the lower surface side but from the side. The constant pressure unit 10B can be lowered in height.

(Other variations)
For example, in the above embodiment, when performing the Vickers hardness test, the configuration in which the sample S is directly placed without placing the constant pressure unit 10 on the sample stage 8 is described as an example. It is not limited. That is, it is possible to perform the Vickers hardness test in a state where the indentation depth measurement reference portion 71 is attached to the lower surface of the indenter shaft base 41 a and the constant pressure unit 10 is placed on the sample stage 8. That is, when performing the Vickers hardness test, the indentation depth measurement reference portion 71 and the constant pressure unit 10 may or may not be attached.

Moreover, in the said embodiment, an instrumentation indentation test is performed by attaching the constant pressure unit mechanism which consists of the indentation depth measurement reference | standard part 71 and the constant pressure unit 10 to the hardness tester which can perform a Vickers hardness test. However, the present invention is not limited to this. For example, a hardness tester capable of performing an instrumented indentation test, in which the position of the indenter shaft displacement detector 7 is fixed, the indentation depth measurement is performed by attaching the constant pressure unit 10. Can maintain stability.
That is, the constant pressure unit mechanism including the indentation depth measurement reference portion 71 and the constant pressure unit 10 can be attached to a hardness tester capable of performing a Vickers hardness test, or can perform an instrumented indentation test. It can also be attached to a hardness tester in which the position of the indenter shaft displacement detector 7 is fixed.

Moreover, in the said embodiment, although the 1st force motor 31 is illustrated as the test force generation part 3, and this invention is applied to the mechanism which can control a test force with an electromagnetic force, it is limited to this. It is not a thing. For example, the present invention may be applied to a mechanism that uses a weight instead of a force motor to switch the test force by adjusting the weight.
Moreover, although the said embodiment demonstrated and demonstrated the structure which rotates the load arm 2 and applies test force to the indenter 4a, it is not limited to this. For example, the present invention may be applied to a configuration in which a test force is directly applied to the indenter shaft 4 without providing the load arm 2.

  In addition, the detailed configuration of each device constituting the hardness tester and the detailed operation of each device can be changed as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Hardness tester 1a Tester main body 2 Load arm 21 Rotating shaft 22 Load shaft 3 Test force generation part 31 1st force motor (test force load means)
32 Second force motor 4 Indenter shaft 4a Indenter 41 Indenter shaft holder 41a Indenter shaft base 41b Indenter shaft guide 41c Leaf spring 5 Objective lens 6 Turret 6a Rotating shaft 7 Indenter shaft displacement detector (intrusion amount detector)
71, 72 Indentation depth measurement reference part (reference part)
71a, 72a Holes 71b, 72b Sample surface contact portion 8 Sample stage 9 Stage lift (up / down device)
10, 10A, 10B Constant pressure unit 11, 11B Sample stage (sample holder)
11a Recess 11b, 111B Shoulder 12, 12B Constant pressure unit case (support)
12a, 124B Upper restriction part 13 Sample stage guide 14 Holding spring (elastic member)
121B Lower end 122B Spring support 123B Diaphragm spring (elastic member)
15 Sample holder (sample holder)
151 Storage Unit 15a Sample Control Unit 15b Projection 20 Imaging Unit 20a Microscope Unit 20b CCD Camera 100 Control Unit 101 CPU
102 RAM
103 Storage unit S Sample

Claims (6)

With an indenter,
A test force loading means for applying a test force to the indenter and pushing the indenter into a surface of a sample;
An intrusion amount detecting means for detecting an intrusion amount of the indenter pushed into the surface of the sample by the test force loading means;
Indentation size detecting means for detecting the size of an indentation formed by pushing the indenter into the surface of the sample by the test force loading means;
First hardness calculation means for calculating the hardness of the sample based on the intrusion amount of the indenter detected by the intrusion amount detection means;
Second hardness calculating means for calculating the hardness of the sample based on the size of the recess detected by the recess size detecting means;
A reference portion having a reference surface when the intrusion amount detecting means detects the intrusion amount of the indenter;
A constant pressure unit having a sample holding part capable of holding the sample, and pressing the sample or the sample holding part at a constant pressure against a reference surface of the reference part;
An elevating device that moves the constant pressure unit in the up and down direction,
The constant pressure unit is
A support part that has an upper restricting part that restricts the upward movement of the sample holding part, and supports the sample holding part so as to be movable in the vertical direction;
An elastic member that urges the sample and the sample holding portion upward, and
When the sample or the sample holding part is pressed against the reference surface of the reference part by being moved upward by the lifting device, a vertical gap is generated between the sample holding part and the upper restricting part. A hardness tester characterized in that it is formed. The sample holder is capable of placing the sample on the upper surface,
The elastic member urges the sample holder from the lower surface side,
The hardness tester according to claim 1, wherein the sample is pressed against the reference surface of the reference portion at a constant pressure. The sample holder is
A storage section for storing the sample movably in the vertical direction;
A sample restricting portion that is provided at an upper end of the storage portion and restricts the upward movement of the sample;
The elastic member urges the sample from the lower surface side,
The hardness tester according to claim 1, wherein the sample is pressed against the reference surface of the reference portion at a constant pressure. The sample holder is
A storage section for storing the sample movably in the vertical direction;
A sample restricting portion that is provided at an upper end of the storage portion and restricts the upward movement of the sample;
The elastic member urges the sample from the lower surface side,
The hardness tester according to claim 1, wherein the sample restricting portion is pressed against the reference surface of the reference portion with a constant pressure. The sample holder is capable of placing the sample on the upper surface,
The elastic member supports the sample holder from the side and urges it upward,
The hardness tester according to claim 1, wherein the sample is pressed against the reference surface of the reference portion at a constant pressure. A reference portion having a reference surface for detecting the indentation amount of the indenter;
A sample holding unit capable of holding a sample, and a constant pressure unit that presses the sample or the sample holding unit to a reference surface of the reference unit with a constant pressure,
The constant pressure unit is
A support part that has an upper restricting part that restricts the upward movement of the sample holding part, and supports the sample holding part so as to be movable in the vertical direction;
An elastic member that urges the sample and the sample holding portion upward, and
When the sample or the sample holding part is pressed against the reference surface of the reference part, a vertical gap is formed between the sample holding part and the upper restricting part. Constant pressure unit mechanism.

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