Hardness tester and program

Abstract

Hardness tester (100), comprising: an intruder (1); a test force loading unit (11, 12) that applies a test force to the indenter (1) and presses the indenter (1) against a sample; a detector (13) that records a value for the test force applied to the indenter (1) by the test force loading unit (11, 12); and a control unit (19) which, in a state in which a predetermined test force is applied to the indenter (1) by the test force load unit (11, 12), and when the value of the test force detected by the detector (13) exceeds a predetermined permissible tolerance relative to the predetermined test force, executes a predetermined process, where the predetermined process includes at least one of an interruption process that interrupts the currently executed test, and a notification process that notifies a user that the value of the test force has exceeded the permissible tolerance during the execution of the test, characterized in that: when the controller (19) executes the interruption process, and after the interruption process has been executed, the controller (19) controls the test force loading unit (11, 12) and reduces the test force applied to the indenter (1) to a preset predetermined value; and The hardness testing device (100) further comprises: a sample table (15) on which the sample is to be placed; and a sample table lifting device (16) which raises and lowers the sample table (15), wherein, after the test force applied to the indenter (1) reaches the predetermined value, the control unit (19) controls the sample table lifting device (16) to lower the sample table (15).

Description

GENERAL STATE OF THE ART1. Field of the invention

[0001] The present invention relates to a hardness testing device and a program. 2. Description of the state of the art

[0002] A conventional hardness tester is known that applies a test force to the surface of a sample using an indenter and evaluates the sample's hardness based on the indentation. A well-known example of such a hardness tester is a Rockwell hardness tester, which evaluates the hardness of a sample based on the indentation depth (see, for example, Japanese Patent JP 2001-108590A). In this Rockwell hardness tester, a preliminary test force is first applied to a sample placed on a sample stage using an indenter. The test force is then gradually increased and finally maintained for a predetermined time at a point where a predetermined test force (full test force) is applied to the sample. The test force is then gradually reduced back to the preliminary test force, at which point the depth of the indentation formed in the sample is measured.

[0003] With the hardness tester described above, a test will continue even if a fluctuation in the test force increases or decreases while the full test force is being applied. This fluctuation can be caused by any factor, such as unintentional contact by the user with the sample table on which the sample rests, with a support element holding the indenter, or with vibration originating from the environment in which the hardness tester is installed. In such cases, the calculated final hardness value will be incorrect, and the measurement accuracy of the hardness tester will be reduced, without the user being able to detect any of these factors.

[0004] CN 2 05 643 053 U discloses sclerometers with a protective function. DE 11 2014 004 389 T5 describes an overload protection device for a force transducer sensor, in which a sample or device under test is protected if excessive forces are applied by the sensor during material testing. BRIEF SUMMARY OF THE INVENTION

[0005] The present invention was conceived in light of the above circumstances and provides a hardness testing device and a program that make it possible to alert a user that a calculated hardness value is incorrect due to an inappropriate fluctuation in a test force.

[0006] To solve the aforementioned problems, a hardness testing device according to claim 1 is provided according to a first aspect of the present invention. According to a second aspect of the present invention, a material, non-volatile, computer-readable medium according to claim 4 is provided which stores an executable set of instructions for controlling a hardness testing device. Further aspects of the present invention are the subject of the dependent claims, the drawings, and the following description of exemplary embodiments.

[0007] Another aspect of the present invention is the hardness testing device described above, in which, in a state where the predetermined test force is applied to the indenter, and when the value of the test force detected by the detector is greater than the value calculated by adding a predefined threshold value to the value for the predetermined test force, the control system performs at least one predetermined process.

[0008] Another aspect of the present invention is the hardness testing device described above, in which the control system performs the interruption process and carries out the notification process.

[0009] Another aspect of the present invention is a program that causes a computer of a hardness tester, comprising an indenter, a force-loading unit that applies a force to the indenter and presses the indenter against a specimen, and a detector that detects a value for the force applied to the indenter by the force-loading unit, to act as a controller that, in a state where a predetermined force is applied to the indenter by the force-loading unit and when the value of the force detected by the detector exceeds a predefined permissible tolerance relative to the predetermined force, executes a predetermined process, wherein the predetermined process comprises at least one interruption process that interrupts the currently executed test and a notification process that notifies a user thatthat the value of the test force exceeded the permissible tolerance during the execution of the test.

[0010] According to the present invention, a user can be notified that a calculated hardness value is incorrect due to an inappropriate fluctuation in a test force. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present invention is described in more detail below with reference to the specified multitude of drawings by means of non-limiting examples of embodiments of the present invention, in which the same reference numerals in the various views of the drawings consistently represent similar parts, and in which: Fig. Figure 1 is a side view showing a configuration of relevant sections of a hardness testing device according to the present invention; Fig. 2 is a block diagram illustrating the functional structure of the hardness tester according to the present invention; Fig. 3 is a diagram that illustrates an exemplary change in the test force during a normal hardness test; Fig. 4 is a flowchart that illustrates the control sequence of the hardness tester; Fig. 5 is a diagram that illustrates an exemplary change in test force during an interruption process; and Fig. Figure 6 is a diagram showing an example of the change in test force during the interruption process. DETAILED DESCRIPTION OF THE INVENTION

[0012] The details shown here are exemplary and serve only to illustrate the embodiments of the present invention and to provide what is considered the most useful and understandable description of the principles and conceptual aspects of the present invention. In this context, no attempt is made to describe structural details of the present invention in more detail than is necessary for a basic understanding of the invention. The description, together with the drawings, makes it clear to those skilled in the art how the forms of the present invention can be implemented in practice.

[0013] One embodiment of the present invention is described below with reference to the drawings. However, the scope of the invention is not limited to the example shown.

[0014] First, a configuration of a hardness testing device 100 according to the present embodiment is described.

[0015] Fig. Figure 1 is a side view showing a configuration of the relevant sections of the hardness tester 100. Fig. Figure 2 is a block diagram of the functional configuration of the hardness tester 100. As shown in Fig. 1 and Fig. As shown in Figure 2, the hardness testing device 100 is configured to include, for example, an arm 11 and a driver 12 for applying a test force, a spring travel sensor 13 as a detector, an arm position sensor 14, a sample table 15, a sample table height adjuster 16 for raising and lowering the sample table 15, a console 17, a memory 18 and a control unit 19.

[0016] The arm 11 is rotatably mounted on a test instrument base body 100a and is configured so that different types of indenters can be exchanged and mounted on a front end of the arm 11. The different types of indenters that can be attached to the arm 11 can include an indenter 1 that forms an indentation in a sample surface, or a flat indenter (not shown in the drawings) that presses against a predetermined object without damaging the object.

[0017] The driver 12 comprises, for example, a stepper motor, a servo motor, or similar device as a drive source 12a. The power generated by the drive source 12a is transmitted via a disc spring 11a to the arm 11, causing the arm 11 to rotate. This rotation brings the front end of the arm 11 closer to the sample stage 15, pressing the indenter 1 or the flat indenter against a sample placed on the sample stage 15. The driver 12 also causes the arm 11 to rotate away from the sample stage 15 and move into a predetermined retraction position. This retraction position creates a gap between the various indenters and the sample stage 15, allowing the indenter or sample on the sample stage 15 to be exchanged or for a predetermined preparation for measurement or the like to be carried out.

[0018] The spring travel sensor 13 detects the amount of travel of the disc spring 11a in the arm 11. Specifically, the spring travel sensor 13 is configured, for example, by a displacement sensor unit (linear scale) that optically reads a glass scale and can detect the amount of travel of the disc spring 11a when the disc spring 11a transmits a force generated by the drive source 12a of the driver 12 to the arm 11. The amount of travel of the disc spring 11a detected by the spring travel sensor 13 is continuously output to the controller 19. Accordingly, the test force acting on the indenter 1 can be continuously detected.

[0019] An arm position sensor 14 detects a displacement of the arm 11. In particular, the arm position sensor 14 is configured, for example, by a displacement sensor unit (linear scale) that optically reads a glass scale and can detect the displacement of the arm 11. The displacement of the arm 11 detected by the arm position sensor 14 is output to the controller 19.

[0020] The sample table 15 is provided below the various indenters mounted on the arm 11, and a sample against which the various indenters press is placed on the sample table 15.

[0021] The sample table height adjuster 16 comprises a support column 16a, which has an external thread on one of its outer circumferential surfaces, and a handle 16, which has an internal thread on one of its inner circumferential surfaces. The external thread of the support column 16a engages with the internal thread of the handle 16b. By turning the handle 16b, the support column 16a is moved up and down along its longitudinal axis, and the sample table 15, mounted at the top of the support column 16a, is moved up and down, thereby setting the height position of the sample table 15.

[0022] Console 17 comprises a display section 17a and an input section 17b. Display section 17a is configured, for example, by an LCD (Liquid Crystal Display) and displays various screens according to a display signal instruction input from the controller 19. Input section 17b comprises, for example, a touchscreen control panel designed to overlay a display screen of display section 17a and includes various control buttons, such as number keys and a start button. An operator signal based on user input is output to the controller 19.

[0023] Memory 18 is configured by a storage device, such as a non-volatile semiconductor memory or a hard disk, and stores data or the like relating to various processes.

[0024] The controller 19 is configured to include a CPU 19a, a RAM 19b and a ROM 19c and controls various sections of the hardness tester 100.

[0025] The CPU 19a retrieves a processing program stored in ROM 19c, opens and then executes the processing program in RAM 19b, thereby performing the overall control of the hardness tester 100.

[0026] The RAM 19b opens the processing program executed by the CPU 19a in a program memory area within the RAM 19b and stores input data, processing results generated during the execution of the processing program, and the like in a data memory area.

[0027] The ROM 19c stores various types of data, different types of processing programs, and the like, which enable the CPU 19a to perform the overall control of the hardness tester 100. In particular, the ROM 19c stores, for example, a hardness test program 191, a hardness test management program 192, and the like.

[0028] Next, the operating procedures of the hardness tester 100 according to the present embodiment will be described.

[0029] The hardness tester 100 is used to perform a hardness test, whereby the hardness of a sample is assessed based on the depth of an indentation formed in the sample by pressing the indenter 1 against the sample. For example, the user, who enters an execution instruction for the hardness test via the console 17, is treated as a trigger to execute the hardness test in coordination with the hardness test program 191, which the CPU 19a of the controller 19 retrieves from the ROM 19c and, if necessary, opens in the RAM 19b.

[0030] Fig. Figure 3 is a diagram illustrating an example of the change in a test force (F) (test force on indenter 1) applied to the specimen during a normal hardness test. As shown in Fig. As shown in Figure 3, during the hardness test, a preliminary test force (F0) is first applied to the indenter 1, and the indenter 1 is pressed into the surface of the specimen for a predetermined time. The test force on the indenter 1 is then gradually increased until a predetermined test force (total test force (F1)) is reached, at which point the test force is maintained for a predetermined time. After the predetermined time has elapsed, the test force on the indenter 1 is gradually reduced until it returns to the preliminary test force (F0). At this point, the depth of the indentation formed in the surface of the specimen (penetration depth) is measured by the displacement of the arm 11, which is detected by the arm position sensor 14.Then, based on a difference between the penetration depth formed by the preliminary test force (F0) and the penetration depth formed by the total test force (F1), a hardness value of the sample (Rockwell hardness) is calculated using a known formula.

[0031] In this example, in the hardness testing device 100 according to the present embodiment, during the execution of the hardness test described above, in a state in which the total test force (F1) is applied to and maintained on the indenter 1, and if a fluctuation of the test force (F) is detected and this value exceeds a predefined permissible tolerance relative to the total test force (F1), an interruption process and a notification process are executed, wherein the interruption process interrupts the currently performed hardness test and the notification process notifies the user that the value of the test force has exceeded the permissible tolerance during the execution of the test.

[0032] Fig. Figure 4 is a flowchart illustrating the control sequence of the hardness tester 100. The test force (F) applied to the indenter 1, which reaches the total test force (F1), is treated as a trigger to initiate the test in Fig. 4 control sequence shown in coordination with the hardness test program 192, which the CPU 19a of the control 19 retrieves from the ROM 19c and, if necessary, opens in the RAM 19b.

[0033] If, as in Fig. As shown in Figure 4, when the test force (F) applied to the indenter 1 reaches the total test force (F1) (START), the controller 19 determines, based on a value determined by the spring displacement sensor 13 (step S1), whether the test force (F) applied to the indenter 1 exceeds a predetermined threshold value (Fth). In other words, the controller 19 determines whether the value of the test force (F) applied to the indenter 1 is greater than a value calculated by adding the threshold value (Fth) to the value for the total test force (F1). This allows the system to detect when the test force (F) has become too high, while maintaining the total test force (F1). The threshold value (Fth) is a predefined value relative to the total test force (F1), but can be defined and changed by the user if necessary.

[0034] If the test force (F) does not exceed the threshold (Fth) (step S1: NO), the controller 19 determines, based on a value detected by the spring deflection sensor 13 (step S2), whether the test force (F) applied to the indenter 1 falls below the predefined threshold (Fth). In other words, the controller 19 determines whether the value of the test force (F) applied to the indenter 1 is less than a value calculated by subtracting the threshold (Fth) from the total test force (F1). This allows the system to detect when the test force (F) has become too low, while maintaining the total test force (F1).

[0035] If the test force (F) is not below the threshold (Fth) (step S2: NO), the controller 19 also determines whether a time period during which the total test force (F1) is maintained has elapsed (step S3). If the time has not elapsed (step S3: NO), the process returns to step S1 and repeats the process from that point onward, whereas if the time has elapsed (step S3: YES), the process ends (END). If there is no excessive fluctuation in the test force (F) while maintaining the total test force (F1), the Fig. 3. Normal hardness test continued.

[0036] Furthermore, if the test force (F) applied to indenter 1 exceeds the threshold value (Fth) in step S1 (step S1: YES), or if the test force (F) applied to indenter 1 falls below the threshold value (Fth) in step S2 (step S2: YES), i.e., if the predefined permissible tolerance based on the total test force (F1) is exceeded, the controller 19 interrupts the currently executed hardness test (interruption process: step S4) and informs the user that the test force value exceeds the permissible tolerance (notification process: step S5). Specifically, "interrupts the currently executed hardness test" refers to a controller that stops the driver 12, stops a counter (not shown in the drawings) that counts the time duration, or the like.Furthermore, “informs the user that the value for the test force exceeds the permissible tolerance” can refer to a control that, for example, displays a message on display section 17a, but can also refer to a control that, for example, outputs a voice or a warning tone.

[0037] Next, the controller 19 controls the driver 12 and initiates the lifting of the arm 11 in a vertical direction (step S6). This gradually reduces the test force (F).

[0038] Next, the controller 19 determines, based on a value detected by the spring travel sensor 13 (step S7), whether the test force (F) has reached a predetermined value (F2). If the test force (F) has not reached the predetermined value (F2) (step S7: NO), the process of step S7 is repeated. The predetermined value (F2) refers to a force acting on the sample table 15 in a state where the handle 16b can be easily rotated and is set, for example, to a value of approximately 1 / 10 of the pre-test force (F0).

[0039] When the test force (F) reaches the specified value (F2) (step S7: YES), the controller 19 controls the driver 12 and stops the lifting of the arm 11 in the vertical direction (step S8), and the process ends (END). Accordingly, the test force (F) applied to the indenter 1 is completely reduced and the test is interrupted, whereupon the user can slightly rotate the handle 16b and slightly lower the sample table 15.

[0040] Fig. Figure 5 shows a diagram of an example of a change in the test force (F) for a case where the test force (F) exceeds the threshold (Fth) (step S1: YES), while the total test force (F1) is maintained. If, as in Fig. As shown in Figure 5, if the test force (F) exceeds the threshold value (Fth), the test is interrupted at that time (P1) and the test force (F) is then reduced in conjunction with the lifting of the arm 11. Furthermore, at the time (P2) when the test force (F) reaches the predetermined value (F2), the lifting of the arm 11 is stopped and the test force (F) then remains constant at the predetermined value (F2).

[0041] Furthermore, it shows Fig. 6. A diagram illustrating an example of a change in the test force (F) in the case where the test force (F) falls below the threshold (Fth) (step S2: YES) while the total test force (F1) is maintained. If, as in Fig.As shown in Figure 6, if the test force (F) falls below the threshold value (Fth), the test is interrupted at this point (P3) and the test force (F) is then reduced in conjunction with the lifting of the arm 11. Furthermore, at the point (P4) when the test force (F) reaches the predetermined value (F2), the lifting of the arm 11 is stopped and the test force (F) then remains constant at the predetermined value (F2).

[0042] As stated above, the hardness testing device 100 according to the present embodiment comprises the indenter 1, the arm 11 and the driver 12, which apply the test force to the indenter 1 and press the indenter 1 against the specimen, the spring displacement sensor 13, which detects a value for the test force applied to the indenter 1, and the control unit 19.In a state where a predetermined test force (the total test force (F1)) is applied to the indenter 1 by the driver 12, and if the test force value detected by the spring deflection sensor 13 exceeds a predefined permissible tolerance relative to the predetermined test force, the controller 19 executes predetermined processes. These processes include an interruption process that pauses the currently executed test and a notification process that informs the user that the test force value has exceeded the permissible tolerance during the execution of the test. Thus, if for any reason an increase or decrease in the test force (F) occurs while the total test force (F1) is being applied, the currently executed test is interrupted, and the user is notified that an increase or decrease has occurred that exceeds the permissible tolerance for the test force (F).Consequently, the user may be notified that the calculated hardness value is incorrect due to an unreasonable fluctuation in the test force. Furthermore, the calculation of a hardness value that is incorrect due to an unreasonable fluctuation in the test force may be interrupted.

[0043] Furthermore, the controller 19 executes a predetermined operation when the predetermined test force (total test force (F1)) is applied to the indenter 1, and if the test force (F) detected by the spring deflection sensor 13 exceeds the value calculated by adding the predetermined threshold (Fth) to the total test force (F1). Therefore, during the application of the total test force (F1), and particularly if the test force (F) exceeds the threshold (Fth), the currently executed test can be interrupted and the user notified. Consequently, the user can be alerted that a hardness value lower than the actual hardness is being calculated inadvertently, and the calculation of this value can be interrupted.

[0044] According to the present embodiment, when the controller 19 executes the interruption process, and after the interruption process has been executed, the controller 19 also controls the driver 12 and reduces the test force applied to the indenter 1 to the preset predetermined value (F2). This prevents a situation in which the full test force (F1) is exerted on the sample table 15 and the user cannot rotate the handle 16b, and after the interruption of the currently performed test, operational procedures that lead to the resumption of the test can be carried out with only a small load.

[0045] In the embodiment described above, an example configuration is described in which, as soon as the test force (F) reaches the predetermined value (F2), the lifting of the arm 11 in the vertical direction is stopped and the user manually lowers the sample table 15. However, a configuration is also possible in which, as soon as the test force (F) reaches the predetermined value (F2), the controller 19 controls the sample table height adjuster 16 and automatically lowers the sample table 15.

[0046] Furthermore, the embodiment described above provides an example of a control sequence in which the notification process is executed after the interruption process. However, the interruption process can also be executed after the notification process. In other words, if a fluctuation occurs that exceeds the permissible tolerance of the test force (F) while the total test force (F1) is being applied, the notification process can be executed immediately, for example by displaying a message on display section 17a, after which the interruption process is executed to stop the driver 12 or similar device.

[0047] Furthermore, the notification process can be executed without the interruption process. In other words, if a fluctuation in the test force (F) occurs that exceeds the permissible tolerance while the total test force (F1) is being applied, the notification process can be executed, for example, by displaying a message on display section 17a, while the currently executed test continues to its conclusion. The notification process can also be executed immediately after detecting a fluctuation that exceeds the permissible tolerance of the test force (F) or after the test has finished. Even with such control sequences, the user can be alerted that the calculated hardness value is incorrect due to the inappropriate fluctuation in the test force.Furthermore, these control sequences allow the user to check the sample after being notified that the calculated hardness value is incorrect and to determine whether to use the value when evaluating the sample.

[0048] Furthermore, it is possible that the notification process will not be executed during the interruption process. In other words, if a fluctuation occurs in the test force (F) that exceeds the permissible tolerance while the total test force (F1) is applied, only the interruption process is executed to stop the driver 12 or similar device. Even with such a control sequence, the fact that the test was interrupted can alert the user that the calculated hardness value is incorrect due to the inappropriate fluctuation in the test force.

[0049] In the embodiment described above, an example using a Rockwell hardness tester as hardness tester 100 is also described. However, the present invention can also be applied to other hardness testers, such as a Vickers hardness tester.

[0050] It is pointed out that the preceding examples have been provided for illustrative purposes only and are in no way to be construed as limiting the present invention. Although the present invention has been described with reference to exemplary embodiments, it is understood that the words used herein are descriptive and explanatory, and not limitative. Amendments may be made within the scope of the attached claims in their respective valid versions without altering the scope of protection and the fundamental concept of the present invention in any aspect.Although the present invention has been described herein with reference to certain structures, materials and embodiments, the present invention is not to be limited to the details disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and applications as they fall within the scope of protection of the attached claims.

[0051] The present invention is not limited to the embodiments described above, and various variants and modifications are possible without deviating from the scope of protection of the present invention.

Claims

[1] Hardness tester (100), comprising: an intruder (1); a test force loading unit (11, 12) that applies a test force to the indenter (1) and presses the indenter (1) against a sample; a detector (13) that records a value for the test force applied to the indenter (1) by the test force loading unit (11, 12); and a control unit (19) which, in a state in which a predetermined test force is applied to the indenter (1) by the test force load unit (11, 12), and when the value of the test force detected by the detector (13) exceeds a predetermined permissible tolerance relative to the predetermined test force, executes a predetermined process, where the predetermined process includes at least one of an interruption process that interrupts the currently executed test, and a notification process that informs a user that the test force value has exceeded the permissible tolerance during the execution of the test, characterized by , that: when the controller (19) executes the interruption process, and after the interruption process has been executed, the controller (19) controls the test force loading unit (11, 12) and reduces the test force applied to the indenter (1) to a preset predetermined value; and The hardness testing device (100) further comprises: a sample table (15) on which the sample is to be placed; and a sample table lifting device (16) which raises and lowers the sample table (15), wherein, after the test force applied to the indenter (1) reaches the predetermined value, the control unit (19) controls the sample table lifting device (16) to lower the sample table (15). [2] Hardness testing device (100) according to claim 1, wherein in the state in which the predetermined test force is applied to the indenter (1) and when the value of the test force detected by the detector (13) is greater than the value calculated by adding a predefined threshold value to the value for the predetermined test force, the control (19) performs the at least one predetermined process. [3] Hardness tester (100) according to claim 1 or 2, wherein the control (19) performs both the interruption process and the notification process. [4] At least one material, non-volatile, computer-readable medium storing an executable set of instructions for controlling (19) a hardness tester (100), the hardness tester (100) comprising an indenter (1), a test force loading unit (11, 12) which applies a test force to the indenter (1) and presses the indenter (1) against a specimen, wherein the set of instructions, when executed by a computer processor, causes the computer processor to perform operations which include: Determining a value for the test force applied to the indenter (1) by the test force loading unit (11, 12); and in a state in which a predetermined test force is applied to the indenter (1) by the test force load unit (11, 12), and if the value of the detected test force exceeds a predefined permissible tolerance relative to the predetermined test force, execute a predetermined process which includes at least one interruption process that interrupts the currently executed test and a notification process that notifies a user that the value of the test force has exceeded the permissible tolerance during the execution of the test, characterized by , that: when the controller (19) executes the interruption process, and after the interruption process has been executed, the controller (19) controls the test force loading unit (11, 12) and reduces the test force applied to the indenter (1) to a preset predetermined value; and The hardness testing device (100) further comprises: a sample table (15) on which the sample is to be placed; and a sample table lifting device (16) which raises and lowers the sample table (15), wherein, after the test force applied to the indenter (1) reaches the predetermined value, the control unit (19) controls the sample table lifting device (16) to lower the sample table (15).

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