JP2012247388A - Hardness testing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hardness testing machine with which hardness tests of different testing methods can be executed by the same testing machine.SOLUTION: A load transmission shaft 36 is supported through a leaf spring 61 to a turret 20. Furthermore, the load transmission shaft 36 is made movable vertically in accordance with a testing force applied by a load mechanism, by a Roberval mechanism fixing upper and lower leaf springs 61 through a support member 62 to a shaft cylinder 27 of the turret 20. A displacement detector 60 which detects a moving amount of the load transmission shaft 36 corresponding to the testing force applied by the load mechanism is connected to the load transmission shaft 36. Namely, the displacement detector 60 detects the moving amount of the load transmission shaft 36 to measure the amount (recessed depth) of an indenter 21 which is connected to a distal end of the load transmission shaft 36, being pushed in with a test piece 100 by applying the testing force.

Description

  The present invention relates to a hardness tester for measuring the hardness of a test piece.

  Test methods for measuring the hardness of a test piece are defined in Japanese Industrial Standards (JIS), International Organization for Standardization (ISO Standards), and the like, and various test machines corresponding to these test methods exist. As a tester for measuring the hardness of such a test piece, a Vickers hardness tester (JIS B7725) used for a Vickers hardness test (JIS Z2244), an ultra-micro load hardness test (JIS Z2255), and instrumentation. An indentation hardness tester used for an indentation hardness test (ISO 14577-1) is known.

  In the Vickers hardness test, the hardness is calculated by measuring the size of the indentation from the diagonal length of the indentation formed by pressing the indenter into the test piece with a predetermined test force. For this reason, in the Vickers testing machine, a test force is applied to the test piece to form an indentation on the surface thereof, a pyramid indenter, a mounting table on which the test piece is mounted, a mounting table on which the test piece is placed An XY stage for sequentially moving a test piece to form an indentation at a plurality of measurement points, a plurality of objective lenses for observing the test piece, and any one of these objective lenses and indenters is a measurement point. And a turret that is switched so as to face each other. Then, the impression formed on the test piece is enlarged through the objective lens, and is observed by an operator using an eyepiece lens or a magnified image display monitor, and the size thereof is measured. As described above, in the Vickers tester, the load axis of the load system that applies the test force to the test piece and the impression formed on the test piece are applied so that the test force can be applied smoothly to the test piece and the indentation is measured. The optical axis of the optical system for observation is coaxial, and the indentation is measured by switching the load system and the optical system by moving the indenter and objective lens with the turret without moving the test piece on which the indentation is formed. It has a configuration (see Patent Document 1).

  On the other hand, in the indentation hardness tester that performs ultra-small load hardness test and instrumented indentation hardness test, the penetration depth of the indenter into the test piece (indentation) when the indenter is pushed into the test piece with a predetermined test force Quantity) is measured and the hardness is calculated. For this reason, in the indentation hardness tester, a test force is applied to the test piece and the triangular pyramid indenter that is pushed into the test piece from its surface, a mounting table on which the test piece is mounted, and a mounting table. An XY stage for moving the test piece and a displacement detector for detecting the displacement amount of the indenter position are provided. In the testing machine described in Patent Document 2, an optical monitor device including an objective lens, an eyepiece, and the like is provided as an auxiliary device, and a position at which the test piece is opposed to the indenter by a XY stage. By moving to the position, the operator can observe the test piece.

Japanese Patent Laid-Open No. 9-15128 JP-A-9-79963

  By the way, in the indentation hardness tester, since the hardness of the test piece is obtained from the indentation amount of the indenter into the test piece as described above, the indenter test corresponding to the test force applied to the test piece by the load system is performed. It is required that the amount of pushing into the piece can be accurately measured. In this type of indentation hardness tester, the optical system is an auxiliary function for observing the test piece as in the tester described in Patent Document 2, and the load is applied as in the Vickers hardness tester. Since the load axis of the system and the optical axis of the optical system are not coaxial, when the operator wants to observe the indentation formed on the test piece, the test piece is moved to the position where the objective lens is disposed. Etc. will be observed. Therefore, when a Vickers hardness tester is attached to a indentation hardness tester and a Vickers hardness test is performed, the XY stage that moves the test piece is changed according to the size of the test piece. It is necessary to change the specifications of the device. In addition, there is a problem that the size of the test piece that can be tested is limited due to the movable range of the XY stage that moves the test piece.

  This invention was made in order to solve the said subject, and it aims at providing the hardness testing machine which can perform the hardness test from which a test method differs with the same testing machine.

  The invention according to claim 1 is a mounting table on which a test piece is placed, an indenter for forming an indentation on the surface of the test piece, a load transmission member having the indenter disposed at a tip, and the load transmission member A load mechanism for applying a test force to the test piece by moving the indenter up and down via an objective lens, an objective lens for observing an indentation formed on the surface of the test piece from above, and the objective lens By supporting and rotating the indentation measuring means for measuring the size of the indentation, the load transmission member and the objective lens, either the indenter or the objective lens is placed on the mounting table. A rotating member that is moved to a position facing the test piece, and an indentation amount detecting means that is disposed on the rotating member and that is connected to the load transmission member and detects the indentation amount of the indenter into the test piece. The above An indentation analyzing means for calculating the hardness of the test piece from the size of the indentation measured by the indentation measuring means, and an indentation amount analyzing means for calculating the hardness of the test piece from the indentation amount detected by the indentation amount detecting means, It is characterized by providing.

  According to a second aspect of the present invention, in the first aspect of the invention, the rotating member is a test indenter for calculating the hardness of the test piece from the size of the indentation and / or the test piece from the indentation amount. A plurality of load transmitting members provided with test indenters for calculating the hardness of the load are supported.

  The invention according to claim 3 is the invention according to claim 2, wherein the test indenter for calculating the hardness of the test piece from the size of the indentation is a quadrangular pyramid indenter, and the test piece is obtained from the indentation amount. The test indenter for calculating the hardness of the is a triangular pyramid indenter.

  According to the first aspect of the present invention, the indentation amount detecting means is disposed on the rotating member, and the indentation analyzing means and the indentation amount analyzing means are provided, so that the hardness of the test piece is determined from the size of the indentation. Hardness tests with different test methods, such as the test to calculate and the test to calculate the hardness of the specimen from the amount of indentation, are easily performed with the same testing machine without changing the specifications of the equipment such as replacing the XY stage. It becomes possible.

  According to the second aspect of the present invention, since the rotating member is provided with the plurality of load transmitting members, the switching of the indenter can be performed smoothly.

  According to the third aspect of the present invention, the plurality of load transmitting members are provided with a quadrangular pyramid-shaped indenter and a triangular pyramid-shaped indenter, respectively, so that a test for determining Vickers hardness and a test for determining Martens hardness Can be easily switched.

1 is a schematic diagram of a hardness tester according to the present invention. FIG. 3 is an explanatory diagram showing the arrangement of objective lenses and the like supported by a turret 20. It is a schematic diagram of a load mechanism for applying a test force to the indenter 21 and an optical system for observing the indentation. It is a block diagram which shows the main electrical structures of the hardness tester which concerns on this invention. It is explanatory drawing which shows typically a mode that an indentation is formed in the test piece 100 with the indenter 21. FIG. 3 is a plan view showing indentations formed on a test piece 100. FIG.

  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 an explanatory view showing the arrangement of the objective lens 22 and the like supported by the turret 20.

  The hardness tester includes a table 11 and an XY stage 12 as a mounting table that is placed on the table 11 and on which a test piece 100 is mounted. The XY stage 12 is for moving the test piece 100 in the X direction (left-right direction in FIG. 1) and the Y direction (direction perpendicular to the paper surface in FIG. 1). The XY stage 12 is provided with a micrometer 13 for moving the test piece 100 in the X direction and a micrometer 14 for moving the test piece 100 in the Y direction. The XY stage 12 is configured to move up and down by the action of the lifting handle 15.

  The hardness tester includes an eyepiece 16 for visually observing the test piece 100, a camera 17 for photographing the test piece 100, and a CRT for displaying an image of the surface of the test piece 100. Rotating member for supporting a display unit 18, an input unit 19 such as a keyboard for inputting various data, a load transmission shaft 36 as a load transmission member having an indenter 21 disposed at a tip, which will be described later, and an objective lens 22 And the turret 20.

  The turret 20 includes load transmission shafts 36 and 46 each having an indenter 21 to be pushed into a test piece 100 placed on the XY stage 12 by a load mechanism, which will be described later, and a 60 × objective lens 22 and 40 ×. Objective lens 23, 20 × objective lens 24, and 10 × objective lens 25. Note that the magnification and the number of the objective lenses 22, 23, 24, and 25 are not limited thereto.

  FIG. 3 is a schematic diagram of a load mechanism for applying a test force to the indenter 21 and an optical system for observing the indentation.

  This hardness tester includes a load mechanism that applies a test force for pushing the indenter 21 disposed at the tip of the load transmission shafts 36 and 46 into the test piece 100, and the test piece 100 placed on the XY stage 12. An optical system for illuminating and observing the indentation is provided.

  As shown in FIG. 3, the turret 20 has a shaft cylinder 27 connected to a shaft 28 via a bearing 29, and rotates around a shaft 28 facing in the vertical direction by operating the knob 26. In FIG. 3, when the test force is applied to the indenter 21 through the load transmission shaft 36 by the rotation of the turret 20, that is, the indenter 21 is disposed at a position facing the test piece 100 shown in FIG. Shows the case.

  The load mechanism includes a lever 32 that can swing around a shaft 31. 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 controls the test force applied to the test piece 100 by the indenter 21 disposed at the tip of the load transmission shaft 36 by controlling the current flowing through the electromagnetic coil 34. Is possible.

  The load transmission shaft 36 is supported by the turret 20 via a leaf spring 61. Further, as shown in FIG. 3, the load transmission shaft 36 has a robust structure in which the upper and lower leaf springs 61 are fixed to the shaft cylinder 27 of the turret 20 via the support member 62 according to the test force applied by the load mechanism. Can be moved up and down. The load transmission shaft 36 is connected to a displacement detector 60 that detects the amount of movement of the load transmission shaft 36 according to the test force applied by the load mechanism.

  The displacement detector 60 is a differential transformer type displacement detector and functions as a push-in amount detecting means of the present invention. That is, the displacement detector 60 detects the amount of movement of the load transmission shaft 36 so that the indenter 21 connected to the tip of the load transmission shaft 36 is pushed into the test piece 100 when a test force is applied. The amount of indentation (indentation depth) is measured. 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. In this embodiment, the load transmission shafts 36 and 46 are disposed on the turret 20, but the displacement detector 60 does not necessarily have to be connected to both the load transmission shafts 36 and 46, respectively. In other words, the displacement detector 60 is any load in which the indenter 21 used for performing a test for obtaining a material parameter obtained from a data set of at least a load / indentation depth such as Martens hardness is disposed. What is necessary is just to be arrange | positioned in the turret 20 in the state connected to the transmission shaft.

  The optical system includes a light source 41, a light tube 42 that guides light from the light source 41 in the horizontal direction, and light guided by the light tube 42 in the hollow portion of the pressing portion 35 in order to illuminate the test piece 100 from above. The half mirror 43 that guides light and transmits the reflected light from the surface of the test piece 100 to the camera 17 side, and the reflected light from the surface of the test piece 100 that has passed through the half mirror 43 is divided into the eyepiece 16 and the camera 17. Half mirror 44. When the objective lens 22 is disposed at the position of the load transmission shaft 36 in FIG. 3, that is, at the observation position of the indentation formed on the test piece 100, the reflected light from the surface of the test piece 100 is pressed by the pressing portion 35. , And enters the eyepiece 16 and the camera 17 through the objective lens 22 and the half mirrors 43 and 44. Accordingly, an enlarged image of the test piece 100 can be observed with the eyepiece 16 and an enlarged image taken by the camera 17 can be displayed on the display unit 18.

  FIG. 4 is a block diagram showing the main electrical configuration of the hardness tester according to the present invention.

  The hardness tester includes a control unit 50 that includes a RAM and a ROM as storage devices and a CPU as a calculation device, and controls the entire device. The control unit 50 is connected to the camera 17, the display unit 18, the input unit 19, the electromagnetic coil 34 of the load mechanism, and the displacement detector 60 described above. Further, the control unit 50 acquires indentation image information obtained by the camera 17 and calculates the hardness of the test piece 100 from the size of the indentation, etc. And an indentation amount analyzing unit 52 as an indentation amount analyzing means for calculating the indentation amount from the displacement amount (depth of penetration of the indenter into the test piece) detected by the vessel 60 and calculating the hardness of the test piece 100.

  FIG. 5 is an explanatory view schematically showing how the indentation 21 forms an indentation on the test piece 100, and FIG. 6 is a plan view showing the indentation formed on the test piece 100. FIG. 6A shows an indentation formed by a quadrangular pyramid indenter, and FIG. 6B shows an indentation formed by a triangular pyramid indenter.

  When executing a Vickers hardness test as a hardness test, an indenter 21 whose tip is a quadrangular pyramid is attached to the tip of a load transmission shaft 36 with a screw 38, and the surface of the test piece 100 is operated by the action of the load mechanism shown in FIG. Is pushed by a depth h (see FIG. 5). Thereafter, the test force is released, the knob 26 shown in FIG. 1 is operated, the turret 20 is rotated, and the objective lens having a desired magnification is moved to face the test piece 100. The diagonal length d (= (dx + dy) / 2) of the indentation (indentation) is measured from the image of the indentation (indentation) formed on the surface of the test piece 100 obtained through the objective lens and the camera 17 (FIG. 6 (a)). 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. In the indentation analysis unit 51 of the control unit 50, the Vickers hardness is calculated from the surface area of the indentation and the test force obtained from the diagonal length d of the indentation (indentation), and the value is displayed as necessary. Is displayed.

  When performing an indentation hardness test as a hardness test, an indenter 21 whose tip is a triangular pyramid is attached to the tip of a load transmission shaft 36 with a screw 38, and the surface of the test piece 100 is applied by the action of the load mechanism shown in FIG. The displacement detector 60 detects the displacement (= depth h) of the position of the indenter 21 when the indenter 21 enters the test piece from the surface of the test piece with the test force applied. In addition, the triangular pyramid indenter in which the impression shown in FIG. 6B is formed is an indenter used when obtaining Martens hardness derived from the relationship between the push-in amount and the test force. In the indentation amount analysis unit 52 of the control unit 50, the Martens hardness is calculated from the indentation amount and the test force, and the value is displayed on the display unit 18 as necessary.

  As described above, in the hardness tester according to the present invention, not only the test for calculating the hardness of the test piece from the size of the indentation as in the Vickers hardness test, but also the indentation amount as in the Martens hardness. The test for calculating the hardness of the test piece can be performed without changing the specification of the apparatus such as replacement of the XY stage.

  Further, since the hardness tester according to the present invention includes the load transmission shafts 36 and 46, for example, the load transmission shaft 36 has a triangular pyramid indenter for Martens hardness test, and the load transmission shaft 46 has a Vickers indenter. A quadrangular pyramid indenter for hardness testing can be provided. Thus, by arranging indenters having different shapes for each load transmission shaft in advance, different test methods are required depending on the material of the test piece 100, or for a plurality of test pieces 100 having different properties. Even when the tests are performed sequentially, it is possible to easily switch to an indenter suitable for the test method simply by rotating the turret 20.

11 Table 12 XY Stage 13 Motor 14 Motor 15 Lifting Handle 16 Eyepiece 17 Camera 18 Display Unit 20 Turret 21 Indenter 22 Objective Lens 23 Objective Lens 24 Objective Lens 25 Objective Lens 26 Knob 27 Axle Tube 28 Axis 29 Bearing 31 Axis 32 Lever 33 Permanent magnet 34 Electromagnetic coil 35 Press part 36 Load transmission shaft 38 Screw 41 Light source 42 Light tube 43 Half mirror 44 Half mirror 50 Control part 51 Indentation analysis part 52 Push-in amount analysis part 60 Displacement detector 61 Plate spring 62 Support member 63 Support member 100 test pieces

Claims (3)

A mounting table for mounting the test piece;
An indenter for forming an indentation on the surface of the test piece;
A load transmission member having the indenter disposed at the tip;
A load mechanism for applying a test force to the test piece by raising and lowering the indenter via the load transmission member;
An objective lens for observing the indentation formed on the surface of the test piece from above;
An indentation measuring means for measuring the size of the indentation via the objective lens;
A rotating member that moves the indenter or the objective lens to a position facing the test piece placed on the mounting table by supporting and rotating the load transmitting member and the objective lens;
An indentation amount detecting means disposed on the rotating member and connected to the load transmission member for detecting the indentation amount of the indenter into the test piece;
Indentation analysis means for calculating the hardness of the test piece from the size of the indentation measured by the indentation measurement means,
An indentation amount analyzing means for calculating the hardness of the test piece from the indentation amount detected by the indentation amount detecting means;
A hardness tester comprising: The hardness tester according to claim 1,
The rotating member includes a plurality of loads provided with a test indenter for calculating the hardness of the test piece from the size of the indentation and / or a test indenter for calculating the hardness of the test piece from the amount of pressing. Hardness tester that supports the transmission member. The hardness tester according to claim 2, wherein
The test indenter for calculating the hardness of the test piece from the size of the indentation is a quadrangular pyramid indenter, and the test indenter for calculating the hardness of the test piece from the indentation amount is a triangular pyramid indenter. testing machine.

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