JP6468134B2 - Hardness testing machine - Google Patents

Description

  The present invention relates to a hardness tester that measures the hardness of a test piece.

  The hardness tester includes an XY stage for moving the test piece in the XY direction, an indenter for forming an indentation on the surface of the test piece, a load mechanism for pressing the indenter against the surface of the test piece, In order to place the indenter or objective lens opposite the test position by supporting and rotating the observation mechanism equipped with an objective lens and CCD camera for observing the size of the indentation formed on the surface and the CCD camera A turret. And it is the structure which determines the hardness of a test piece based on the size of the indent observed by the observation mechanism.

  In Patent Document 1, a pressing process in which an indenter is pressed against the surface of a test piece by a load mechanism, an observation process in which the size of the indentation formed on the surface of the test piece is observed by an observation mechanism, and a test based on the size of the observed indentation. A hardness tester that automatically and continuously executes a determination step for determining the hardness of a piece is disclosed.

  Further, Patent Document 2 discloses a hardness tester that pre-programs a test position on sample shape data when performing a hardened layer depth evaluation.

JP2015-59756A JP 2014-126417 A

  Regarding the hardness test of the material subjected to the surface hardening treatment of the hardened steel material, JIS (Japanese Industrial Standard) G 0557 defines “a method for measuring the depth of the carburized hardened layer of steel”. In JIS G 0559, “Method for measuring flame quenching of steel and induction hardening hardened layer depth” is prescribed. In the measurement of the depth of the hardened layer, a hardness transition curve is created by performing a plurality of hardness tests from the surface (quenched surface) of the test piece as a sample toward the inside. And when measuring the "effective hardened layer depth", the distance from the surface of a test piece to the position which becomes the hardness designated beforehand is measured. Further, when measuring the “total cured layer depth”, the distance from the surface of the test piece to the position where the hardness of the cured layer and the fabric cannot be distinguished is measured.

  Such an effective hardened layer depth or total hardened layer depth is a pressing process in which the indenter is pressed against the surface of the test piece by the load mechanism, and an observation process in which the size of the indentation formed on the surface of the test piece is observed by the observation mechanism; In the case of measuring the hardness of the test piece from the size of the observed indentation with a hardness tester that automatically and continuously executes a plurality of test points, the number of test points Setting is difficult, and there is a problem that skill is required to set the number of test points. That is, when a large number of test points are set, the hardness test is performed even on originally unnecessary test points, and the test efficiency deteriorates. On the other hand, when the number of test points is set to be small, the hardness test of the necessary test points is not performed, and it is necessary to perform an additional hardness test again.

  The present invention has been made to solve the above-described problems, and a hardness test capable of executing a hardness test at a necessary and sufficient number of test points when measuring an effective cured layer depth or a total cured layer depth. The purpose is to provide a machine.

  The invention according to claim 1 is an XY stage for moving a test piece in the XY direction, an indenter for forming an indentation on the surface of the test piece, and a load mechanism for pressing the indenter against the surface of the test piece. An observation mechanism for observing the size of the indentation formed on the surface of the test piece, a hardness determination unit for judging the hardness of the test piece based on the size of the indentation observed by the observation mechanism, and the load A pressing step of pressing the indenter against the surface of the test piece by a mechanism; an observation step of observing the size of an indentation formed on the surface of the test piece by the observation mechanism; and a hardness of the test piece by the hardness determination unit. A hardness tester comprising: a control unit configured to repeatedly execute a hardness measurement operation including a determination step for determining a thickness a plurality of times while moving the test piece in the XY direction. Hardness of the specimens was determined by serial hardness determination unit, when it becomes less than a preset value, characterized in that to terminate the hardness measuring operation.

  The invention according to claim 2 includes an XY stage for moving the test piece in the XY direction, an indenter for forming an indentation on the surface of the test piece, and a load mechanism for pressing the indenter against the surface of the test piece. An observation mechanism for observing the size of the indentation formed on the surface of the test piece, a hardness determination unit for judging the hardness of the test piece based on the size of the indentation observed by the observation mechanism, and the load mechanism The pressing step of pressing the indenter against the surface of the test piece, the observation step of observing the size of the indentation formed on the surface of the test piece by the observation mechanism, and the hardness of the test piece by the hardness determination unit A hardness tester comprising: a control unit configured to repeatedly execute a hardness measurement operation including a determination step by moving the test piece in the XY direction a plurality of times, wherein the control unit includes the hardness When the difference between the hardness of the test piece determined by the fixing unit and the hardness of the test piece previously determined by the hardness determination unit is equal to or less than a preset value, the hardness measurement operation It is characterized by terminating.

  According to a third aspect of the present invention, in the hardness tester according to the second aspect, the control unit determines the hardness of the test piece determined by the hardness determination unit and the previous determination by the hardness determination unit. The hardness measurement operation is terminated when a phenomenon in which the difference between the hardness of the test piece is equal to or less than a preset value occurs continuously for a preset number of times.

  The invention according to claim 4 is the hardness tester according to any one of claims 1 to 3, wherein the control unit presses the indenter once against the surface of the test piece, The hardness measurement operation for observing the size of the indentation formed on the surface once and determining the hardness of the test piece once is repeatedly executed a plurality of times.

  The invention according to claim 5 is the hardness tester according to any one of claims 1 to 3, wherein the control unit presses the indenter against the surface of the test piece a plurality of times, The hardness measurement operation for observing the size of the indentation formed on the surface a plurality of times to determine the hardness is repeatedly executed a plurality of times.

  According to the first aspect of the present invention, a hardness test for measuring the effective hardened layer depth can be executed with a necessary and sufficient number of test points. For this reason, it becomes possible to perform the measurement of the effective hardened layer depth efficiently.

  According to invention of Claim 2, the hardness test for measuring the total hardened layer depth can be performed in a required and sufficient number of test points. For this reason, it becomes possible to perform the measurement of the total hardened layer depth efficiently.

  According to invention of Claim 3, it becomes possible to perform the hardness test for measuring the total hardened layer depth more correctly.

  According to the fourth aspect of the present invention, it is possible to perform pressing of the indenter, observation of the size of the indentation, and determination of hardness at a necessary and sufficient number of test points.

  According to the fifth aspect of the present invention, the number of movements of the indenter and the observation mechanism can be reduced by continuously pressing the indenter.

It is a schematic diagram of the hardness testing machine concerning this invention. It is a general | schematic perspective view of XY stage 12 vicinity. It is a schematic diagram of the raising / lowering mechanism which raises / lowers the XY stage. FIG. 3 is an explanatory diagram showing the arrangement of objective lenses and the like supported by a turret 20. 2 is a schematic diagram of a load mechanism for applying a test force to the indenter 19 and the indenter 21 and an observation mechanism for observing an indentation formed on a test piece 100. FIG. FIG. 5 is a schematic diagram for explaining how indentations are formed on a test piece 100 by an indenter 21. 3 is a plan view showing indentations formed on a test piece 100. FIG. It is a block diagram which shows the main control systems of the hardness tester based on this invention. It is a flowchart which shows the measurement operation | movement which measures the effective hardened layer depth with the hardness tester which concerns on 1st Embodiment of this invention. 3 is a graph showing the relationship between the position of a test point and the hardness of a test piece 100. It is a flowchart which shows the measurement operation | movement which measures the effective hardened layer depth with the hardness tester which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the measurement operation | movement which measures the total hardened layer depth with the hardness tester which concerns on 3rd Embodiment of this invention. It is a flowchart which shows the measurement operation | movement which measures the total hardened layer depth with the hardness tester which concerns on 4th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of a hardness tester according to the present invention. FIG. 2 is a schematic perspective view of the vicinity of the XY stage 12. Further, FIG. 3 is a schematic diagram of a lifting mechanism that lifts and lowers the XY stage 12.

  The hardness tester includes a table 11 and an XY stage 12 that is arranged on the table 11 and holds a test piece and moves it in the XY directions. The XY stage 12 moves the test piece in the X direction (left-right direction in FIG. 1) and the Y direction (direction perpendicular to the paper surface in FIG. 1), and positions the test piece on the XY plane. As shown in FIG. 2, the XY stage 12 is provided with a moving mechanism having a motor 13 for horizontally moving the XY stage 12 in the X direction and a motor 14 for moving the XY stage 12 in the Y direction. Has been.

  The XY stage 12 is configured to move in the vertical direction (Z direction) by the action of the lifting mechanism shown in FIG. That is, the support portion 51 that supports the XY stage 12 is supported by the elevating member 52 having a rack 53 formed on the side surface thereof. The rack 53 in the elevating member 52 meshes with a pinion 54 that rotates by driving of the motor 15. For this reason, the XY stage 12 moves up and down by driving the motor 15.

  As shown in FIG. 1, this hardness tester supports an eyepiece 16 for visually observing a test piece, a camera 17 for photographing the test piece, an indenter 21 and objective lenses 23 and 24, and the like. And a rotating turret 20. The turret 20 rotates around an axis that faces the vertical direction by operating the knob 26 or by driving a motor 30 described later. The hardness tester includes a touch panel type liquid crystal display unit 59 that also functions as an input unit and a display unit.

  FIG. 4 is an explanatory diagram showing the arrangement of the objective lenses and the like supported by the turret 20.

  The turret 20 includes indenters 19 and 21 to be pushed into a test piece placed on the XY stage 12, a 2x objective lens 22, a 5x objective lens 23, a 40x objective lens 24, and a 50x objective. A lens 25 is provided. The indenters 19 and 21 and the objective lenses 22, 23, 24, and 25 are arranged on a circle around the rotation center C of the turret 20. The number of indenters 19 and 21 and the magnification and number of objective lenses 22, 23, 24, and 25 are not limited to this.

  Referring to FIG. 1 again, this material testing machine includes a display unit 55 such as a liquid crystal monitor for displaying an image of the surface of the test piece, and a keyboard 57 functioning as input means for inputting various data. The computer 50 includes a mouse 58 and a main body 56. The computer 50 includes a storage device such as a ROM and a RAM and a CPU that executes logical operations in a main body 56.

  FIG. 5 is a schematic diagram of a load mechanism for applying a test force to the indenter 19 and the indenter 21 and an observation mechanism for observing an indentation formed on the test piece. 5 shows a cross section at the position indicated by the alternate long and short dash line in FIG.

  This hardness tester includes a load mechanism that applies a test force to the indenters 19 and 21 to push the tips of the indenters 19 and 21 against the test pieces, and a test piece placed on the XY stage 12. And an optical system for illuminating and observing the indentation.

  As shown in FIG. 5, the turret 20 has a shaft cylinder 27 connected to a rotary shaft 28 via a bearing 29. The turret 20 can be adjusted in the vertical direction by operating a knob 26 or by driving a motor 30 described later. It rotates about the rotating shaft 28 that faces it. FIG. 5 shows a case where a test force is applied to the indenter 21 by the rotation of the turret 20 via the load transmission shaft 36, that is, a case where the indenter 21 is disposed at a position facing the test piece. When a test force is applied to the indenter 19, the indenter 19 is disposed at the position of the indenter 21 shown in FIG.

  The load mechanism includes a lever 32 that can swing around a shaft 31 that faces in the horizontal direction. A hollow pressing portion 35 is disposed at one end of the lever 32. The pressing portion 35 is configured to press a contact portion 37 attached to an end portion of the load transmission shaft 36 connected to the indenter 21 as the lever 32 swings. A permanent magnet 33 is attached to the other end of the lever 32. An electromagnetic coil 34 is disposed outside the permanent magnet 33. The permanent magnet 33 and the electromagnetic coil 34 constitute a voice coil motor. This voice coil motor serves as an electromagnetic load mechanism, and can control the test force applied to the test piece by the indenter 21 disposed at the tip of the load transmission shaft 36 by controlling the current flowing through the electromagnetic coil 34. It becomes possible. The test force at this time can be changed in stages.

  The load transmission shaft 36 is supported by a robust structure in which upper and lower leaf springs 61 are fixed to a shaft cylinder 27 of the turret 20 via a support member 62, and can be moved up and down according to a test force applied by a load mechanism. It has become. A differential transformer type displacement detector 60 for detecting the amount of movement of the load transmission shaft 36 is connected to the load transmission shaft 36. The displacement detector 60 is connected to the shaft cylinder 27 of the turret 20 through a support member 63, and moves in synchronization with the load transmission shaft 36 by the rotation of the turret 20.

  The observation mechanism includes an LED light source 41, a light tube 42 that guides light from the LED light source 41 in the horizontal direction, and light guided by the light tube 42 to illuminate the test piece from above in the hollow portion of the pressing portion 35. A half mirror 43 that guides the reflected light from the surface of the test piece to the camera 17 side and a half that divides the reflected light from the surface of the test piece that has passed through the half mirror 43 into the eyepiece 16 and the camera 17. And a mirror 44. When the objective lens 22 is arranged at the position of the load transmission shaft 36 in FIG. 5, that is, at the observation position of the indentation formed on the test piece, the reflected light from the surface of the test piece is reflected by the objective lens 22 and the pressing portion 35. , And enters the eyepiece 16 and the camera 17 through the half mirrors 43 and 44. As a result, an enlarged image of the test piece can be observed with the eyepiece 16, and an enlarged image taken by the camera 17 can be displayed on the display unit 55 in the computer 50. The case where the other objective lenses 23, 24, 25 are arranged at the observation position of the indentation is the same as that by the objective lens 22.

  FIG. 6 is an explanatory view schematically showing how the indentation 21 forms an indentation on the test piece 100, and FIG. 7 is a plan view showing the indentation formed on the test piece 100. In addition, these figures are things when performing a Vickers hardness test.

  Of the indenters 19 and 21, the indenter 21 is for executing a Vickers hardness test as a hardness test, and the tip thereof has a quadrangular pyramid shape. As shown in FIG. 6, the indenter 21 is pushed into the surface of the test piece 100 by a depth h by the action of the load mechanism shown in FIG. Then, the test force is released, and the turret 20 shown in FIG. 1 is rotated to move the objective lens having a desired magnification to a position facing the test piece 100. The diagonal length d [d = (dx + dy) / 2] of the indentation is measured from the image of the indentation formed on the surface of the test piece 100 obtained through the objective lens and the camera 17 (see FIG. 7). The Vickers hardness is proportional to the value obtained by dividing the test force by the surface area of the indentation assuming that the bottom surface is square and the apex angle is the same pyramid as the indenter 21. Then, the Vickers hardness is calculated from the surface area of the indentation obtained from the diagonal length d (mm: millimeter) of the indentation and the test force.

  Here, when the test force is F (N: Newton), the Vickers hardness HV is expressed by the following equation.

HV = 0.1891 (F / d ² )
As the other indenter 19 of the indenters 19 and 21, for example, a pyramid indenter having a rhombus bottom used for the Knoop hardness test is used.

  FIG. 8 is a block diagram showing a main control system of the hardness tester according to the present invention.

  This hardness tester includes a control unit 80 that controls the entire apparatus. The control unit 80 includes the above-described camera 17, liquid crystal display unit 59, LED light source 41, displacement detector 60, electromagnetic coil 34, computer 50, motor 30 for rotating the turret 20, and the XY stage 12 as X, Y, It is connected to motors 13, 14, and 15 for moving in the Z direction. Further, the control unit 80 is connected to a storage unit 81 that stores various information for operating the hardness tester, including various setting values to be described later and position information of test points at which a hardness test is to be executed. ing.

  The control unit 80 also includes an image processing unit 82 for image processing of an image captured by the camera 17, and a diagonal length d of the impression measured by the image processing by the image processing unit 82. A hardness determination unit 83 for calculating and determining the thickness. The control unit 80 may be configured in the computer 50.

  When performing a hardness test using the hardness tester having the above-described configuration, first, the XY stage 12 is moved in the X, Y, and Z directions to position the test piece 100, and the motor The turret 20 is rotated by driving 30 to move the indenter 19 or the indenter 21 to a test position facing the test piece 100. Then, the indenter 19 or the indenter 21 is pressed against the test piece 100 by the load mechanism shown in FIG. Thus, when a necessary indentation is formed on the test piece 100, the turret 20 is rotated by driving the motor 30, and one of the objective lenses 22, 23, 24, 25 is opposed to the indentation in the test piece 100. Move to the position to be. At this time, among the objective lenses 22, 23, 24, and 25, the objective lens corresponding to the size of the indentation is disposed at a position facing the indentation. An image processing unit 82 in the control unit 80 performs image processing on an image of an impression taken by the camera 17 via the objective lenses 22, 23, 24, and 25. And the hardness determination part 83 in the control part 80 calculates and determines the hardness of the test piece 100 by measuring the diagonal length d of an impression from the image of the impression after image processing.

  Next, a measurement operation for measuring the effective hardened layer depth using the hardness tester having the above-described configuration will be described. FIG. 9 is a flowchart showing a measuring operation for measuring the effective hardened layer depth by the hardness tester according to the first embodiment of the present invention. When measuring the effective hardened layer depth by the hardness tester according to the first embodiment, the hardness measurement operation is terminated when the hardness of the test piece is equal to or less than a preset set value. The configuration is adopted.

  When measuring the effective hardened layer depth with this hardness tester, set in advance the position of the test point where the hardness test should be performed continuously and the set value of the hardness when the hardness measurement operation ends. Keep it. This set value is set using, for example, the keyboard 57 and the mouse 58 in the computer 50 and stored in the storage unit 81 shown in FIG. Note that a plurality of test points are set from the surface (quenched surface) of the test piece 100 toward the inside.

  When the above preparation process is completed, the hardness test is started. At this time, first, by moving the XY stage 12 in the X, Y, and Z directions, the test piece 100 is positioned so that a preset test point faces the indenter 19 or the indenter 21 (step S11). . Then, the indenter 19 or the indenter 21 is pressed against the test piece 100 to form an indentation (step S12). Next, the turret 20 is rotated, and an image of this indentation is taken by the camera 17 via the objective lenses 22, 23, 24, 25 (step S13). Then, after the image processing unit 82 performs image processing on the image, the hardness determination unit 83 determines the hardness of the test piece 100 based on the diagonal size of the indentation (step S14).

  Next, the determined hardness of the test piece 100 is compared with a preset value (step S15). When the hardness of the test piece 100 is larger than the preset hardness, the process returns to step S11 and the above steps are repeated. And if the hardness of the test piece 100 becomes below the preset hardness, a measurement operation will be complete | finished (step S16). The set value of the hardness is, for example, 550 HV in the case of the effective hardened layer depth of steel.

  By adopting such a configuration, when measuring the effective hardened layer depth with a hardness tester, a hardness test for measuring the effective hardened layer depth is executed at a necessary and sufficient number of test points. be able to. For this reason, it becomes possible to perform the measurement of the effective hardened layer depth efficiently.

  In the case of adopting a configuration in which the hardness of the test piece at that position is measured while sequentially moving the test piece 100 as described above, the position of the test piece 100 and the test piece at that position as the test progresses. The relationship with 100 hardness can be recognized. For this reason, it becomes possible to display these relationships as a graph.

  FIG. 10 is a graph showing the relationship between the position of such a test point and the hardness of the test piece 100.

  This graph is displayed on, for example, the display unit 55 or the touch panel type liquid crystal display unit 59 in the computer 50. By checking this graph, the operator can recognize the hardness in real time.

  Next, the measurement operation according to another embodiment of the hardened layer depth measurement by the hardness tester having the above-described configuration will be described. FIG. 11 is a flowchart showing a measuring operation for measuring the effective hardened layer depth by the hardness tester according to the second embodiment of the present invention. Even when the effective hardened layer depth is measured by the hardness tester according to the second embodiment, the hardness measurement operation is performed when the hardness of the test piece is equal to or lower than a preset value. Adopts a configuration that ends. And in this 2nd Embodiment, after forming the impression on the test piece 100 continuously for the preset number of times, the structure which performs the observation of the formed impression continuously is employ | adopted.

  When measuring the effective hardened layer depth in the second embodiment, the position of the test point to be continuously subjected to the hardness test, the set value of the hardness when the hardness measurement operation is finished, and the continuous Then, the number N (for example, several to ten times) of executing formation and observation of the indentation is set. This set value is set using, for example, the keyboard 57 and the mouse 58 in the computer 50 and stored in the storage unit 81 shown in FIG. Note that a plurality of test points are set from the surface (quenched surface) of the test piece 100 toward the inside.

  When the above preparation process is completed, the hardness test is started. At this time, first, a preset number N of continuous executions of the formation and observation of indentations is read (step S21). Further, by moving the XY stage 12 in the X, Y, and Z directions, the test piece 100 is positioned so that a preset test point faces the indenter 19 or the indenter 21 (step S22). Then, the indenter 19 or the indenter 21 is pressed against the test piece 100 to form an indentation (step S23). The positioning of the test piece 100 and the formation of the indentation are repeated until the set number N is reached (step S24).

  Next, an impression is taken. At this time, the turret 20 is rotated to place the objective lenses 22, 23, 24, and 25 at the observation position, and the XY stage 12 is moved in the X, Y, and Z directions, whereby the test piece 100 is moved to a plurality of indentations. Are sequentially positioned so that the first indentation faces the objective lenses 22, 23, 24, 25 (step S25). And the image of an impression is image | photographed with the camera 17 via the objective lenses 22, 23, 24, and 25 (step S26).

  Next, after the image of the indentation is image-processed by the image processing unit 82, the hardness of the test piece 100 is calculated and determined based on the diagonal size of the indentation by the hardness determination unit 83 (step S27). Then, the determined hardness of the test piece 100 is compared with a preset value (step S28). When the hardness of the test piece 100 is larger than the preset hardness, it is determined whether or not the comparison operation has reached the set number of times N (step S29). If not, the process returns to S25. The positioning of the test piece 100, the photographing of the indentation, and the hardness determination are repeated. On the other hand, if the hardness of the test piece 100 is equal to or lower than the preset hardness, the measurement operation is terminated (step S30). Then, after repeating the positioning of the test piece 100, photographing, determination of the hardness, and comparison with the set value for the set number N without the hardness of the test piece 100 being equal to or lower than the preset hardness. (Step S29), the process returns to Step S22 and the above operation is repeated.

  By adopting such a configuration, when measuring the effective hardened layer depth with a hardness tester, a hardness test for measuring the effective hardened layer depth is executed at a necessary and sufficient number of test points. be able to. For this reason, it becomes possible to perform the measurement of the effective hardened layer depth efficiently. In addition, the number of rotations of the turret 20 can be reduced by continuously forming the indentation.

  Next, the measurement operation for measuring the total hardened layer depth using the above-described hardness tester will be described. FIG. 12 is a flowchart showing a measuring operation for measuring the total hardened layer depth by the hardness tester according to the third embodiment of the present invention. When measuring the total hardened layer depth by the hardness tester according to the third embodiment, the difference between the hardness of the determined test piece and the hardness of the test piece determined at the previous measurement is set in advance. The configuration is adopted in which the hardness measurement operation is terminated when the set value is not more than the set value.

  When measuring the effective hardened layer depth with this hardness tester, the position of the test point to be subjected to the hardness test continuously, and the set value of the difference in hardness when the hardness measurement operation is finished, Is set in advance. This set value is set using, for example, the keyboard 57 and the mouse 58 in the computer 50 and stored in the storage unit 81 shown in FIG. Note that a plurality of test points are set from the surface (quenched surface) of the test piece 100 toward the inside.

  When the above preparation process is completed, the hardness test is started. At this time, first, by moving the XY stage 12 in the X, Y, and Z directions, the test piece 100 is positioned so that a preset test point faces the indenter 19 or the indenter 21 (step S41). . Then, the indenter 19 or the indenter 21 is pressed against the test piece 100 to form an indentation (step S42). Next, the turret 20 is rotated, and an image of this indentation is taken by the camera 17 via the objective lenses 22, 23, 24, 25 (step S43). Then, after this image is processed by the image processing unit 82, the hardness determination unit 83 calculates and determines the hardness of the test piece 100 based on the diagonal size of the indentation (step S44). When the hardness determination is not completed for the two measurement points, Steps S41 to S44 are repeated (Step S45).

  When the determination of hardness is completed for two or more measurement points (step S45), the difference between the determined hardness of the test piece 100 and the hardness of the test piece 100 determined last time is calculated (step S46). ). Then, the difference in hardness is compared with a preset value (step S47). When the difference in hardness is larger than a preset value, the process returns to step S41 and the above steps are repeated. If the hardness difference is equal to or smaller than a preset value, the measurement operation is terminated (step S48).

  By adopting such a configuration, when measuring the total hardened layer depth by a hardness tester, a hardness test for measuring the total hardened layer depth is executed at a necessary and sufficient number of test points. be able to. For this reason, it becomes possible to perform the measurement of the total hardened layer depth efficiently.

  Next, the measurement operation according to another embodiment of the total hardened layer depth measurement will be described. FIG. 13 is a flowchart showing a measurement operation for measuring the total hardened layer depth by the hardness tester according to the fourth embodiment of the present invention. In addition, also when measuring the total cured layer depth by the hardness tester according to the fourth embodiment, the difference between the hardness of the determined test piece and the hardness of the test piece determined at the previous measurement, A configuration is adopted in which the hardness measurement operation is terminated when the value is equal to or less than a preset set value. And in this 4th Embodiment, after forming indentation to the test piece 100 continuously as many times as preset, the structure which observes the formed indentation continuously is employ | adopted.

  When measuring the total hardened layer depth with this hardness tester, the position of the test point to be subjected to the hardness test continuously, and the set value of the difference in hardness when the hardness measurement operation is finished, The number N (for example, several times to 10 times) of executing the formation and observation of the indentation is set in advance. This set value is set using, for example, the keyboard 57 and the mouse 58 in the computer 50 and stored in the storage unit 81 shown in FIG. Note that a plurality of test points are set from the surface (quenched surface) of the test piece 100 toward the inside.

  When the above preparation process is completed, the hardness test is started. At this time, first, a preset number of times for performing the formation and observation of the indentation continuously is read (step S51). Further, by moving the XY stage 12 in the X, Y, and Z directions, the test piece 100 is positioned so that a preset test point faces the indenter 19 or the indenter 21 (step S52). Then, the indenter 19 or the indenter 21 is pressed against the test piece 100 to form an indentation (step S53). The positioning of the test piece 100 and the formation of the impression are repeated until the set number N is reached (step S54).

  Next, an impression is taken. At this time, the turret 20 is rotated to place the objective lenses 22, 23, 24, and 25 at the observation position, and the XY stage 12 is moved in the X, Y, and Z directions, whereby the test piece 100 is moved to a plurality of indentations. Are sequentially positioned so that the first indentation faces the objective lenses 22, 23, 24, 25 (step S55). And the image of an impression is image | photographed with the camera 17 via the objective lenses 22, 23, 24, and 25 (step S56).

  Next, after the image of the impression is processed by the image processing unit 82, the hardness of the test piece 100 is calculated by the hardness determination unit 83 based on the diagonal size of the impression (step S57). Then, the difference between the determined hardness of the test piece 100 and the previously determined hardness of the test piece 100 is calculated (step S58). However, only when the initial hardness is determined, this calculation is not performed because there is no hardness for which the difference should be calculated. Then, the calculated difference in hardness is compared with a preset set value (step S59). When the difference in hardness is larger than a preset set value, it is determined whether or not the comparison operation has reached the set number of times (step S60). If not, the process returns to step S55. Repeat test piece positioning, impression imaging, hardness determination, and difference calculation. On the other hand, if the difference in hardness is equal to or less than a preset set value, the measurement operation is terminated (step S61). Then, the positioning of the test piece 100, imaging, determination of hardness, calculation of the difference, and comparison with the set value are performed by the set number N without the difference in hardness being equal to or less than a preset set value. After repeating (step S60), the process returns to step S52 to repeat the above operation.

  By adopting such a configuration, when measuring the total hardened layer depth by a hardness tester, a hardness test for measuring the total hardened layer depth is executed at a necessary and sufficient number of test points. be able to. For this reason, it becomes possible to perform the measurement of the total hardened layer depth efficiently. In addition, the number of rotations of the turret 20 can be reduced by continuously forming the indentation.

  Next, a measurement operation according to still another embodiment of the total hardened layer depth measurement will be described.

  In the third and fourth embodiments described above, in measuring the total hardened layer depth, a difference between the hardness of the determined test piece and the hardness of the test piece determined at the previous measurement is set in advance. A configuration is adopted in which the hardness measurement operation is terminated when the set value or less is reached. On the other hand, in the measurement operation according to the fifth embodiment, the hardness of the test piece 100 determined by the hardness determination unit 83 and the test piece 100 determined last time by the hardness determination unit 83 in the hardness tester described above. A configuration is adopted in which the hardness measurement operation is terminated when a phenomenon in which the difference between the hardness and the difference is less than or equal to a preset value occurs continuously for a preset number of times M (for example, three times). Yes.

  That is, when this embodiment is adopted, in the third embodiment shown in FIG. 12, the hardness of the determined test piece 100 is calculated in the case of calculating the difference from the previously determined hardness of the test piece 100 (step S46). The phenomenon in which the difference between the hardness of the test piece 100 determined by the hardness determination unit 83 and the hardness of the test piece 100 previously determined by the hardness determination unit 83 is equal to or less than a preset set value is set in advance. The measurement operation is terminated when the error occurs for M consecutive times. Further, when this embodiment is adopted, also in the fourth embodiment shown in FIG. 13, the hardness of the determined test piece 100 is calculated in the case of calculating the difference from the previously determined hardness of the test piece 100 (step S58). The phenomenon in which the difference between the hardness of the test piece 100 determined by the hardness determination unit 83 and the hardness of the test piece 100 previously determined by the hardness determination unit 83 is equal to or less than a preset set value is set in advance. The measurement operation is terminated when the error occurs for M consecutive times. When such a configuration is adopted, it is possible to more accurately execute a hardness test for measuring the total hardened layer depth.

  In the first and second embodiments described above, the case where the effective hardened layer depth measurement is performed on the test piece 100 will be described. In the third, fourth, and fifth embodiments, the test piece 100 is measured. The case of measuring the total hardened layer depth has been described. However, after measuring the effective hardened layer depth, the total hardened layer depth may be continuously measured.

DESCRIPTION OF SYMBOLS 11 Table 12 XY stage 13 Motor 14 Motor 15 Motor 17 Camera 19 Indenter 20 Turret 21 Indenter 22 Objective lens 23 Objective lens 24 Objective lens 25 Objective lens 30 Motor 31 Axis 32 Lever 33 Permanent magnet 34 Electromagnetic coil 35 Press part 41 LED light source 50 Computer 53 Rack 54 Pinion 55 Display unit 56 Main body 57 Keyboard 58 Mouse 59 Liquid crystal display unit 60 Displacement detector 80 Control unit 81 Storage unit 82 Image processing unit 83 Hardness determination unit 100 Test piece

Claims (5)

An XY stage for moving the test piece in the XY direction;
An indenter for forming an indentation on the surface of the test piece;
A load mechanism for pressing the indenter against the surface of the test piece;
An observation mechanism for observing the size of the indentation formed on the surface of the test piece;
A hardness determination unit that determines the hardness of the test piece based on the size of the indentation observed by the observation mechanism;
A pressing step of pressing the indenter against the surface of the test piece by the load mechanism, an observation step of observing the size of the indentation formed on the surface of the test piece by the observation mechanism, and the test piece by the hardness determination unit A control unit that repeatedly executes a hardness measurement operation including a determination step of determining the hardness of the test piece a plurality of times while moving the test piece in the XY direction;
In a hardness tester comprising:
The control unit terminates the hardness measurement operation when the hardness of the test piece determined by the hardness determination unit is equal to or less than a preset set value. Machine. An XY stage for moving the test piece in the XY direction;
An indenter for forming an indentation on the surface of the test piece;
A load mechanism for pressing the indenter against the surface of the test piece;
An observation mechanism for observing the size of the indentation formed on the surface of the test piece;
A hardness determination unit that determines the hardness of the test piece based on the size of the indentation observed by the observation mechanism;
The pressing step of pressing the indenter against the surface of the test piece by the load mechanism, the observation step of observing the size of the indentation formed on the surface of the test piece by the observation mechanism, and the hardness determination unit A control unit that repeatedly performs a hardness measurement operation including a determination step of determining hardness, a plurality of times while moving the test piece in the XY direction;
In a hardness tester comprising:
In the control unit, the difference between the hardness of the test piece determined by the hardness determination unit and the hardness of the test piece determined last time by the hardness determination unit is equal to or less than a preset set value. Sometimes, the hardness tester ends the hardness measurement operation. In the hardness tester according to claim 2,
The control unit is a phenomenon in which a difference between the hardness of the test piece determined by the hardness determination unit and the hardness of the test piece determined last time by the hardness determination unit is equal to or less than a preset set value. A hardness tester that terminates the hardness measurement operation when the occurrence of the occurrence occurs continuously a preset number of times. In the hardness tester according to any one of claims 1 to 3,
The controller presses the indenter once against the surface of the test piece, observes the size of the indentation formed on the surface of the test piece once, and determines the hardness of the test piece once. A hardness tester that repeats operations multiple times. In the hardness tester according to any one of claims 1 to 3,
The controller repeatedly presses the indenter against the surface of the test piece a plurality of times, and repeats a hardness measurement operation that determines the hardness by observing the size of the indentation formed on the surface of the test piece a plurality of times. Hardness testing machine to be executed.

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