JP3266457B2 - Automatic Rockwell hardness tester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic Rockwell hardness tester for performing a hardness test by pressing an indenter against a hardness measuring portion of a test piece.

[0002]

2. Description of the Related Art A Rockwell hardness tester forms an indentation by pressing an indenter with a predetermined test load on a hardness measuring portion of a test piece, and detects the depth of the formed indentation with a displacement meter. To determine the Rockwell hardness of the test piece. Usually, indentations are formed at a plurality of measurement points for one test piece, and the Rockwell hardness is determined from the average value of the depths of the plurality of indentations.

[0003]

However, the conventional Rockwell hardness tester is inferior in test efficiency for the following reasons, and is an automatic test apparatus for automatically performing various hardness tests and tensile tests on test specimens. There is a problem that it is difficult to apply to. (1) The relative movement between the measurement points of the indenter is manually performed visually. (2) The indenter is pressed against the test piece using the weight and the lever, and when changing the pressing load according to the type of the test piece, the operator manually replaces the weight. . (3) The operator manually replaces the indenter according to the test piece. (4) When testing a thin plate-shaped test piece, it is necessary to replace the normal anvil with a small spot anvil in order to minimize the gap between the test piece and the anvil (load receiving member). The operator manually performs the replacement work.

An object of the present invention is to provide an automatic Rockwell hardness tester which can improve test efficiency and can be incorporated in an automatic test apparatus.

[0005]

The present invention is applied to an automatic Rockwell hardness tester for measuring Rockwell hardness by pressing an indenter against a hardness measuring portion of a test piece. Then, an XY stage movable in the X direction and the Y direction perpendicular to each other, an anvil abutting on the back surface of the hardness measurement part of the test piece mounted on the XY stage, and the anvil. A test piece fixing device that fixes the test piece by narrowing the pressure with
A holding member holding a diamond indenter and a steel ball indenter is driven to cause any one of the indenters to face the hardness measurement unit of the test piece, and the indenter facing the hardness measurement unit to move in the X direction. And a Z-direction that is orthogonal to both the Y-direction and a pressing device that presses the indenter against the hardness measurement unit to form an indentation, and measures the depth of the indentation formed in the hardness measurement unit. A displacement meter and an indenter switching device for controlling a test piece fixing device to fix a test piece mounted on the XY stage, and for switching an indenter according to preset test information or plate thickness information of the test piece. XY stage and press to switch the test load according to the test information or plate thickness information, press the indenter against the hardness measurement part with the test load, and form indentations at multiple positions on the hardness measurement part. Control means for controlling the device; ; And a calculating means for calculating a Rockwell hardness from the detection value of the displacement meter for indentation, thereby solving the above problems.

[0006]

The control means controls the test piece fixing device to fix the test piece between the anvil and the test piece fixing device with a narrow pressure, and the indenter according to the preset test information or the test piece thickness information. Switch. Further, the test load is switched according to the test information or the plate thickness information, and the indenter is pressed against the hardness measurement portion by the test load to form indentations at a plurality of positions of the hardness measurement portion. The calculating means calculates Rockwell hardness from the depths of the plurality of indentations detected by the displacement meter.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a side view of an automatic Rockwell hardness tester according to the present invention. The XY stage 2 installed on the base 1
A board 21 connected to the base 1, a step motor 22 for driving in the X direction, a step motor 23 for driving in the Y direction,
A moving plate 24 is provided which is moved in the X direction (the direction orthogonal to the paper surface) and the Y direction by both step motors 22 and 23.

An anvil 31 is fixed to the frame 3 placed on the moving plate 24, and the test piece TP is moved on the anvil 31 so that the hardness measurement part A (FIG. 2) of the test piece TP is located. It is set at a predetermined position on the plate 4. A clamp cylinder 41 is also held on the moving plate 24, and a pressing member 42 for narrowing the test piece TP between the anvil 31 and the piston rod of the cylinder 41 is connected to the piston rod. Presser member 4
As shown in FIG. 2, when the cylinder 41 contracts, the holding member 42 abuts against the right and left portions of the test piece TP in the hardness measurement section A and presses the anvil 31. I do. The crosses in the hardness measurement portion A indicate measurement points where indentations should be formed.

A load mechanism 50 is supported on the base 1 via a support member 43. The load mechanism 50 includes a motor 52 for rotating the pulley 51, and a timing belt 53 driven by the rotation of the pulley 51 to rotate the pulley 54.
And a ball screw 55 that rotates integrally with the pulley 54, an elevating member 56 having a nut portion with which the ball screw 55 is screwed and held by a guide GD so as to be able to elevate and lower in the Z direction, and connected to the elevating member 56. And a pressing device 57.
The pressing device 57 includes a load cell 571 connected to the elevating member 56, a rotation drive unit 572 connected to the load cell 571, and a motor 57 held by the rotation drive unit 572.
3 and an indenter holding member 57 rotated by a motor 573
4 and a plurality of indenters 575 (FIG. 3) fixed to the lower surface of the indenter holding member 574.

As shown in FIG. 3, a gear G2 formed on the indenter holding member 574 meshes with a gear G1 connected to the output shaft of the motor 573, and the indenter holding member 574 is driven to rotate by the rotation of the motor 573. It rotates with respect to the part 572. The plurality of indenters 575 are mounted on concentric circles about the rotation axis L of the indenter holding member 574, and one of the indenters is turned by the rotation of the holding member 574 to the test piece T.
It is opposed to the hardness measurement part A of P. Multiple indenters 575
Is, for example, a steel ball indenter or a conical diamond indenter. The rotation drive unit 572 includes a non-contact type sensor 58 for detecting whether the indenter 575 is located at a position facing the hardness measurement unit A, and an indenter 5 for measuring the depth of an indentation.
A displacement gauge 59 (FIG. 1) for detecting the vertical displacement of the sensor 75 is attached.

The above-described actuators such as motors and cylinders are driven and controlled by a control device 101 shown in FIG. Reference numeral 102 in FIG. 4 denotes a personal computer for giving various commands to the control device 101;
Denotes a display device and a printer device for displaying and printing test results and the like, respectively.

The type of indenter and the test load used for the hardness test differ depending on the test conditions and the type of test piece. Control device 1
01 stores a plurality of types of combinations of indenters and test loads according to known test information and plate thickness information of test pieces, and stores any of these combinations according to the test pieces TP to be subjected to the hardness test. Is selected, and the indenter and test load are automatically switched.

An example of the operation of the hardness tester configured as described above will be described below. Moving plate 24 of XY table 2
Is set in advance to the initial position. When information relating to the test piece TP is input by the personal computer 102, the control device 101 selects an indenter 575 and a test load from the above-described table in accordance with the input information, and the motor 573 in order to make the selected indenter 575 face the anvil 31. Drive. The rotation of the motor 573 causes the indenter holding member 574 to rotate via the gears G1 and G2.
75 reaches the position facing the anvil 31 and the sensor 58
Output a signal to that effect, motor 573 is stopped.

The test piece TP is transported by a suction type transport device (not shown) and is placed at a predetermined position on the moving plate 24 of the XY table 2. At this time, the hardness measurement portion A of the test piece TP is located on the anvil 31 and faces the indenter 575. Cylinder 4
1, the holding member 42 is lowered, and both sides of the hardness measurement portion are pressed against the anvil 31 to be fixed.

In this state, the motor 52 is driven to form an indentation at one measurement point (indicated by a cross). The ball screw 55 rotates via the pulley 51, the timing belt 53, and the pulley 54 by the driving force of the motor 52, and the lifting member 56
And the pressing device 57 descends, and the indenter 575 is pressed to the measurement point. First, the load cell 57 is set so that a reference load (smaller than the test load, for example, 10 kg) acts on the measurement point.
The motor 52 is controlled while monitoring the output of “a”. As a result, indentations are formed at the measurement points, and the displacement amount S1 of the indenter 575 from the reference position at this time is measured by the displacement meter 59.

After holding the reference load for several seconds, the motor 52 is driven and controlled, and a test load (for example, 100 kg) is applied to the measurement point by the indenter 575, and the test load is kept as it is for a predetermined time (for example, 2 to 10 seconds). Degree) hold. The test load was applied to the personal computer 102 as described above.
Is a value selected from the table according to the input information input from. After a lapse of a predetermined time, the motor 575 is driven in the reverse direction so that the reference load acts again on the measurement point, and the displacement S2 of the indenter 575 from the reference position at that time is measured. The above S1 and S2 are input to the control device 101, and the difference between them is calculated as the depth D of the indentation.

When D is calculated for one measurement point,
The indenter 575 is once raised, and the motor 22 or 23 of the XY table 2 moves the moving plate 24, that is, the test piece TP, to X or Y until the next measurement point faces the indenter 575.
Drive in the direction. Next, an indentation is formed by performing the same operation as described above, and the depth D is calculated. When D is obtained for all measurement points by repeating these operations,
The average value DAV of D is calculated, and the Rockwell hardness of the test piece TP is calculated from this DAV. The average value of the remaining data may be obtained by excluding the maximum value and the minimum value of D, and the Rockwell hardness may be calculated from the average value.
Information such as the calculated Rockwell hardness and the depth of each indentation can be displayed on the display device 103 or printed by the printer device 104.

As described above, in this embodiment, the operation of exchanging the indenter 575 in accordance with the test piece TP and the operation of moving the test piece TP in the XY directions to change the measurement point are automatically performed. The test load is automatically controlled according to the type of the test piece. In addition, since the test piece TP is narrowed between the anvil 3 and the test piece TP by the holding member 42, a gap is formed between the test piece and the anvil 31 even if the test piece has a thin plate shape, a warp, or a twist. This does not occur, and the measurement error can be reduced to a minimum.

In the configuration of the above embodiment, the pressing member 4
2 and the cylinder 41 serve as a test piece fixing device,
Reference numeral 3 denotes an indenter switching device, the load mechanism 50 constitutes a pressing device, and the control device 101 constitutes control means and calculation means.

The configurations of the test piece fixing device, the indenter switching device, and the pressing device are not limited to those in the embodiment.

[0021]

Since the present invention is constructed as described above, the operation of sequentially moving the test piece with respect to the indenter to change the measurement point, the operation of changing the pressing load according to the type of the test piece, and The work of exchanging the indenter according to the test piece is fully automated, and the provision of the test piece fixing device eliminates the need to replace the indenter with a spot anvil when testing a thin plate-shaped test piece. Therefore, the test efficiency is greatly improved, and the present invention can be applied to an automatic test apparatus that automatically performs various hardness tests and tensile tests on test specimens.

[Brief description of the drawings]

FIG. 1 is a side view showing the entire configuration of an automatic Rockwell hardness tester according to one embodiment of the present invention.

FIG. 2 is a plan view showing a positional relationship between a holding member and a hardness measurement section of a test piece.

FIG. 3 is a sectional view showing details of an indenter switching device.

FIG. 4 is a schematic diagram showing a configuration of a control system.

[Explanation of symbols]

 2 XY table 31 Anvil 41 Cylinder 42 Holding member 50 Load mechanism 57 Pressing device 101 Control device 571 Load cell 573 Motor 574 Indenter holding member 575 Indenter A Hardness measurement unit TP Test piece

Continuation of the front page (56) References JP-A-5-133865 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 3/44 JICST file (JOIS)

Claims (1)

(57) [Claims] 1. An automatic Rockwell hardness tester for measuring a Rockwell hardness by pressing an indenter against a hardness measuring portion of a test piece, comprising: an XY stage movable in an X direction and a Y direction orthogonal to each other. An anvil that is in contact with the back surface of the hardness measuring portion of the test piece placed on the XY stage, a test piece fixing device that narrows and fixes the test piece between the anvil, and a diamond indenter And an indenter switching device that drives a holding member holding the steel ball indenter to cause any one of the indenters to face the hardness measurement unit of the test piece, and the indenter that faces the hardness measurement unit to the X. A pressing device that moves the indenter against the hardness measurement unit to form an indentation by moving the indenter in the Z direction orthogonal to both the direction and the Y direction, and a depth of the indentation formed in the hardness measurement unit. And an XY stage for measuring displacement Controlling the test piece fixing device to fix the test piece placed thereon, controlling the indenter switching device to switch the indenter according to preset test information or plate thickness information of the test piece, An XY stage and a pressing device for switching the test load according to the information or the thickness information, pressing the indenter against the hardness measurement unit with the test load, and forming the indentations at a plurality of positions of the hardness measurement unit. An automatic Rockwell hardness tester, comprising: control means for controlling the pressure, and arithmetic means for calculating Rockwell hardness from the detected values of the displacement meter with respect to the plurality of indentations.