JP2004205281A - Hardness testing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform hardness tests using different evaluating and measuring methods in a hardness testing machine. <P>SOLUTION: The hardness testing machine is constituted so that a penetration quantity detecting means detects the penetration quantity (that is, the depth of a dent) of the pressure element 5 pushed in a sample S from the surface thereof when the dent is formed in the surface of the sample by the pressure element 5, the hardness based on the detected penetration quantity of the sample is calculated by a first hardness calculating means, the distance between the predetermined characteristic points of the dent formed by the pressure element 5 is detected by a dent length detecting means and the hardness based on the detected distance between the characteristc points of the sample is calculated by a second hardness calculating means. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a hardness tester for measuring the hardness of a sample by forming a depression on the surface of the sample.
[0002]
[Prior art]
Conventionally, a hardness tester that evaluates and measures the hardness of a sample based on applying a load to the surface of the sample with an indenter to form a depression is used.
As such a hardness tester, when the indenter is pressed against the sample with a predetermined load, the depth at which the indenter is pushed into the sample and penetrates (the depth of the recess formed by the indenter in the sample) is measured, and the hardness is measured. A Rockwell hardness tester for calculating is known (for example, see Patent Document 1). A Vickers hardness tester that measures the size of a dent formed by pressing an indenter against a sample with a predetermined load (for example, the length between predetermined points of the dent (diagonal length)) and calculates hardness. Is known (for example, refer to Patent Document 2).
[0003]
[Patent Document 1]
Japanese Patent No. 3170256 [Patent Document 2]
JP 2000-292333 A
[Problems to be solved by the invention]
However, the Rockwell hardness tester and the Vickers hardness tester use different methods for evaluating and measuring hardness in the first place, and recently, for users who evaluate and test the hardness of various samples, Hardness testers must be prepared separately, which is inconvenient.
[0005]
Therefore, an object of the present invention is to provide a versatile hardness tester that can perform hardness tests with different evaluation and measurement methods.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the invention according to claim 1 has the following features.
A hardness tester (1) for measuring the hardness of a sample (S) based on a depression formed by an indenter (5) on the surface of the sample,
Force applying means (for example, an arm operating unit 4) for applying a predetermined test force for pushing the indenter into the sample surface;
An intrusion amount detection unit (e.g., an indenter shaft displacement detection unit 20) that detects an intrusion amount of the indenter pushed from the sample surface by the force applying unit;
A depression length detecting means (for example, the control unit 100 and the imaging unit 10) for detecting a distance between predetermined characteristic points of the depression formed by the indenter being pressed into the sample surface;
First hardness calculating means (for example, the control unit 100) for calculating the hardness of the sample based on the intrusion amount detected by the intrusion amount detecting means;
A second hardness calculation unit (for example, the control unit 100) that calculates the hardness of the sample based on a distance between the predetermined feature points detected by the depression length detection unit;
It is characterized by having.
[0007]
According to the first aspect of the present invention, based on the acting force generated by the force applying means, the indenter is given a predetermined test force and is pushed into the surface of the sample to form a depression on the surface of the sample. When forming the depression, the penetration amount detecting means detects the penetration amount of the indenter pressed from the sample surface (that is, the depth of the depression), and the first hardness calculating means based on the detected penetration amount. Calculates the hardness of the sample. Further, the indentation length detecting means detects the distance between predetermined characteristic points of the indentation formed by the indenter, and the second hardness calculating means calculates the hardness of the sample based on the detected distance between the characteristic points. calculate.
In other words, by measuring the hardness of the sample based on the depth of the recess by measuring the hardness of the sample based on the depth of the recess by applying a predetermined test force to the sample surface using an indenter. can do.
Therefore, at least two types of hardness tests can be performed with the indentation formed on the surface of the sample. Therefore, it is possible to select a hardness test method according to the sample and purpose, and it can be used as a versatile hardness tester.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2 are partial cross-sectional side views showing a hardness tester to which the present invention is applied. FIG. 3 is a block diagram showing a main configuration of the hardness tester.
As shown in FIGS. 1 and 2, a hardness tester 1 includes a tester main body 2 on which each component is disposed, a load arm 3 rotatably supported by the tester main body 2, An arm operating section 4 as a force applying means for applying an acting force (test force) to the arm 3 to operate the load arm; a turret 8 rotatably provided on the tester main body 2 below the load arm 3; An indenter shaft 6 attached to the turret 8 and having an indenter 5 at the tip end; an objective lens 7 attached to the turret 8; a sample stage 9 opposed to the turret 8 and on which the sample S is placed; The imaging unit 10 is configured to image a dent formed in the sample S on the sample 9. The operation of each unit of the hardness tester 1 is controlled by the control unit 100 shown in FIG.
[0009]
The load arm 3 has an arm main body 31 and a rotating shaft 32 that supports one end 31 a of the arm main body 31 to the tester main body 2. The other end of the arm body 31 branches into a fork of a first other end 31b and a second other end 31c, and the first other end 31b is shaped like a leaf spring having flexibility. Is formed.
A load shaft 33 elastically supported by a coil spring 33a is provided between the lower surface of the arm main body 31 and the tester main body 2 on the lower surface side of the arm main body 31. Further, the arm body 31 includes an arm displacement detection unit 34 that detects an opening amount between the first other end 31b and the second other end 31c when the load arm 3 (arm body 31) operates. Provided.
[0010]
The arm main body 31 has one end 31a of the arm main body 31 rotatably supported by the tester main body 2 by a rotation shaft 32, and a test force for operating the load arm 3 at the first other end 31b. Is connected to an arm operating section 4 which generates an acting force of the arm. Then, with the operation of the arm operation unit 4, the arm main body 31 rotates around the rotation shaft 32. As the arm body 31 rotates downward, the arm body 31 pushes the load shaft 33 downward to move it. The load shaft 33 transmits the drive and operation of the arm body 31 (the load arm 3) to the indenter shaft 6 (see FIG. 1).
[0011]
The arm displacement detection unit 34 includes, for example, a scale on which graduations at predetermined intervals are engraved, and a linear encoder that optically reads the graduations of the scale. When the indenter 5 is pushed into the sample S through the intermediary, the opening (spring displacement) between the first other end 31b and the second other end 31c is detected, and an arm displacement signal based on the detected opening is detected. It outputs to the control part 100 mentioned later. The opening amount (spring displacement amount) corresponds to the pressing force (test force) of the indenter 5 pushing the sample S or the load applied to the sample S.
[0012]
The arm operating unit 4 includes a servo motor 41, a ball screw 43, a timing belt 42 that is wound around a motor shaft 41 a of the servo motor 41 and a screw shaft 43 a of the ball screw 43, a fixing jig 44 held by the ball screw 43, and the like. It is configured. The arm operating section 4 is connected to the load arm 3 with the leaf spring 44a of the fixing jig 44 fixed to the first other end 31b of the arm body 31.
[0013]
The servo motor 41 is driven based on a drive control signal input from the control unit 100. The driving force of the motor shaft 41a of the servo motor 41 rotated by the driving of the servo motor 41 is transmitted to the screw shaft 43a of the ball screw 43 via the timing belt 42, and the ball screw 43 rotates. The fixing jig 44 is moved up and down by the rotational driving of the ball screw 43.
As described above, the arm operating unit 4 moves the fixing jig 44 up and down based on the driving of the servo motor 41, and moves the fixing jig 44 to the first other end 31 b of the arm body 31 connected to the fixing jig 44. The drive (drive force) is transmitted, and the arm main body 31 (the load arm 3) is rotated. When the arm operating unit 4 operates the load arm 3, the leaf spring 44a bends.
[0014]
The sample table 9 includes a sample stage 91 on which the sample S is mounted, a stage elevating unit 92 provided on the lower surface of the sample stage 91, and the like. The stage elevating section 92 has a screw portion 92a, and the sample stage 91 can be moved up and down with respect to the tester main body 2 by rotating the screw portion 92a.
[0015]
The turret 8 includes a turret body 81, a rotating shaft 82 that rotatably supports the turret body 81 on the tester main body 2, and the like.
The turret main body 81 includes the indenter shaft 6, the objective lens 7, and the indenter shaft displacement detecting unit 20 as an intrusion amount detecting unit that detects a displacement amount of the indenter shaft 6. The indenter shaft 6 is provided on the turret body 81 via the indenter shaft holding portion 61. When the turret body 81 rotates, the arrangement of the indenter shaft 6 and the objective lens 7 is switched.
[0016]
The indenter shaft holding portion 61 includes a vertical holding member 61a and leaf springs 61b, 61b extending laterally from the vertical holding member 61a. The indenter shaft 6 is elastically supported by the leaf springs 61b, 61b. The sample S is provided perpendicular to the mounting surface of the sample S on the sample stage 91, particularly, the surface (upper surface) of the sample mounted on the sample stage 91.
An indenter 5 is provided at the lower end of the indenter shaft 6 so as to be exchangeable.
Then, as shown in FIG. 1, the turret 8 (turret main body 81) is rotated, and the indenter shaft 6 is switched to an arrangement corresponding to the load shaft 33, whereby the load shaft 33 moves downward with the rotation of the load arm 3. To the indenter shaft 6. Then, the indenter 5 can be pressed against the sample S and pushed.
[0017]
The objective lens 7 is a lens unit attached to the microscope unit 11 of the imaging unit 10 described later, and rotates the turret 8 (turret main body 81) to correspond to the objective lens 7 to the imaging unit 10 as shown in FIG. When the arrangement is switched to the arrangement to be performed, the imaging of the sample S by the imaging unit 10 becomes possible.
[0018]
The indenter axis displacement detection unit 20 includes, for example, a scale on which graduations at predetermined intervals are engraved, and a linear encoder that optically reads the graduations of the scale. When the indenter axis 6 forms a depression in the sample S, The moving amount (that is, the amount of intrusion of the indenter 5 into the sample S and the depth of the depression) is detected, and an indenter axis displacement signal based on the detected amount of displacement is output to the control unit 100 described later.
[0019]
The imaging unit 10 includes a microscope unit 11, a CCD camera 10a (see FIG. 3) attached to the microscope unit 11, an illumination device (not shown) for illuminating the observation position of the sample S, and the like. Imaging of the dent formed on the surface of. Then, the imaging unit 10 (CCD camera 10a) outputs the image data of the imaged dent to the control unit 100 described later.
[0020]
The control unit 100 is configured by an arithmetic unit including a CPU, a ROM, a RAM, and the like, and by executing a predetermined program stored in the ROM, a predetermined operating condition set for performing a predetermined hardness test. (Operation conditions for each hardness test) Operation control of each part for forming a dent, data based on the dent formed in the sample S, test force at the time of forming the dent, and each hardness test set in advance The hardness of the sample S is calculated based on the hardness calculation formula corresponding to
[0021]
For example, the control unit 100 compares the arm displacement signal input from the arm displacement detection unit 34 with preset arm displacement data set in advance. Then, in order to rotate the load arm 3 so that the indenter 5 acts on the sample S with a predetermined test force (load), a drive control signal for controlling the driving of the arm operating unit 4 (servo motor 41) is transmitted to the servo motor 41. Output to
[0022]
Further, the control unit 100 calculates the hardness of the sample S based on the indenter axis displacement signal input from the indenter axis displacement detection unit 20 as first hardness calculation means. The first hardness calculating means measures the hardness of the sample S from the amount of intrusion (depth of the depression) into which the indenter 5 is pushed into the sample S. For example, the hardness is calculated based on a Rockwell hardness test. I do.
[0023]
In addition, the control unit 100 analyzes the image data of the dent input from the imaging unit 10 by performing predetermined image processing or the like, automatically measures the size of the dent, and performs a predetermined feature. The distance between points is detected.
Further, the control unit 100 calculates the hardness of the sample S based on a distance between predetermined feature points of the dent detected by the control unit 100 (dent length detecting means) as a second hardness calculating unit. . The second hardness calculating means measures the hardness of the sample S from the size of the depression (distance between predetermined feature points) formed by pressing the indenter 5 into the sample S. For example, Vickers hardness The hardness is calculated based on the test.
[0024]
Next, the operation of the hardness test in the hardness tester 1 will be described.
For example, first, the indenter 5 for the Rockwell hardness test is attached to the indenter shaft 6, the turret 8 is rotated, and the arrangement for forming the depression in the hardness test as shown in FIG. Is switched to an arrangement corresponding to the load shaft 33. Then, the sample S is placed on the sample stage 91 of the sample stage 9, and the sample stage 91 is adjusted to a predetermined height and position.
[0025]
Next, the operation unit 100 causes the hardness tester 1 to perform an operation for performing an operation for a Rockwell hardness test. Based on this operation input, the arm operating unit 4 is driven to rotate the load arm 3 downward. With the rotation of the load arm 3 downward, the load shaft 33 is pressed by the arm body 31 and moves downward, and at the same time, moves the indenter shaft 6 in contact with it downward. The indenter shaft 6 pushes the indenter 5 attached to the tip of the indenter shaft 6 into the sample S to form a depression. When the indenter 5 forms a depression in the sample S, the control unit 100 controls the driving of the arm operating unit 4 based on an arm displacement signal related to the opening amount (spring displacement amount) detected by the arm displacement detecting unit 34. The indenter 5 is pushed into the sample S with a predetermined test force by rotating the load arm 3.
[0026]
Then, when the indenter 5 forms a depression in the sample S, the indenter axis displacement detection unit 20 detects the amount of movement and the amount of displacement of the indenter shaft 6, and outputs an indenter axis displacement signal based on the detected amount of displacement. Output to 100. The control unit 100 calculates the Rockwell hardness based on the input indenter shaft displacement signal, and displays the calculated result (measured value) on a display unit (not shown).
Thus, a Rockwell hardness test can be performed.
[0027]
Further, for example, when the indenter 5 for the Vickers hardness test is attached to the indenter shaft 6, the turret 8 and the sample table 9 are adjusted in the same manner as described above, and the hardness tester 1 Perform the operation for performing the operation for the hardness test.
Then, as described above, based on the controlled drive of the arm operating unit 4, the load arm 3 rotates downward, and moves the indenter shaft 6 downward via the load shaft 33. The indenter shaft 6 pushes the indenter 5 attached to the tip of the indenter shaft 6 into the sample S to form a depression.
[0028]
Next, the turret 8 is rotated to switch to an arrangement for observing dents in a hardness test, that is, an arrangement in which the objective lens 7 corresponds to the imaging unit 10 as shown in FIG. Then, the imaging unit 10 captures an image of the depression formed in the sample S, and outputs image data of the captured depression to the control unit 100. The control unit 100 analyzes the input image data, calculates the length of the diagonal of the substantially rectangular recess formed by the indenter 5 for the Vickers hardness test, and calculates the Vickers hardness based on the length of the diagonal. The calculated result (measured value) is displayed on a display unit (not shown).
Thus, a Vickers hardness test can be performed.
[0029]
As described above, depending on the hardness tester 1 according to the present invention, when the indenter is pressed against the sample with a predetermined load, the depth at which the indenter is pushed into the sample and penetrates (the depth of the depression formed by the indenter in the sample). (For example, a Rockwell hardness test) and a hardness based on the size of a recess formed by pressing an indenter against a sample with a predetermined load (for example, a length between predetermined feature points of the recess). A test (eg, Vickers hardness test) can be performed together. In other words, it can be said that this is a universal hardness tester.
[0030]
Note that, in the above embodiment, the Rockwell hardness test and the Vickers hardness test are performed in the hardness tester 1 as an example. However, the present invention is not limited to this. A hardness test such as a Brinell hardness test or a Knoop hardness test may be performed. In that case, the indenter 5 corresponding to the hardness test is prepared, and the control unit 100 stores and inputs the operation control of the testing machine corresponding to the hardness test and the hardness calculation formula corresponding to each hardness test. What should I do?
[0031]
Further, in the above embodiment, the control unit 100 analyzes the image data of the dent and automatically measures the size of the dent. However, the present invention is not limited to this, and the control unit 100 displays the dent on an observation screen for observing the dent with a measuring microscope. Mechanically moving the scale to be measured to measure the size of the depression, or by touch-inputting the feature points of the depression on the display screen (touch panel) on which the depression imaged by the imaging unit is displayed. The distance between the feature points may be measured and detected.
[0032]
In addition, it goes without saying that specific detailed structures and the like can be appropriately changed.
[0033]
【The invention's effect】
According to the hardness tester of the present invention, when the indenter forms a depression on the surface of the sample, the penetration amount detecting means detects the amount of penetration of the indenter from the sample surface (that is, the depth of the depression). A hardness test based on the detected intrusion amount, and a distance between predetermined feature points of the recess formed by the indenter detected by the recess length detecting means, and a hardness based on the detected distance between the feature points. Testing can be performed.
In other words, a predetermined test force is applied to the sample surface by an indenter to form a depression, thereby measuring the hardness of the sample based on the depth of the depression, for example, a Rockwell hardness test, and based on the size of the depression. The hardness of the sample can be measured, for example, a Vickers hardness test.
As described above, at least two types of hardness tests can be performed with the indentation formed on the surface of the sample, so that a hardness test method according to the sample and the purpose can be selected. It can be used as a reliable hardness tester.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional side view of a hardness tester according to the present invention.
FIG. 2 is a partial cross-sectional side view of a hardness tester according to the present invention.
FIG. 3 is a block diagram showing a control system of the hardness tester according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hardness tester 2 Tester main body 3 Load arm 31 Arm main body 34 Arm displacement detecting part 4 Arm operating part (force applying means)
41 Servo motor 5 Indenter 6 Indenter shaft 7 Objective lens 8 Turret 9 Specimen table 10 Imaging unit (hollow length detecting means)
10a CCD camera 20 Indenter axis displacement detection unit (intrusion amount detection means)
100 control unit (hollow length detecting means, first hardness calculating means, second hardness calculating means)
S sample

Claims (1)

A hardness tester that measures the hardness of the sample based on the indenter forming a depression on the surface of the sample,
Force applying means for applying a predetermined test force for pushing the indenter into the sample surface,
Intrusion amount detection means for detecting the intrusion amount of the indenter pushed from the sample surface by the force applying means,
A depression length detecting means for detecting a distance between predetermined characteristic points of the depression formed by the indenter being pressed into the sample surface,
First hardness calculating means for calculating the hardness of the sample based on the amount of intrusion detected by the amount of intrusion detecting means,
Second hardness calculating means for calculating the hardness of the sample based on the distance between the predetermined feature points detected by the recess length detecting means,
A hardness tester comprising:

Images