JPH0868738A - Hardness meter - Google Patents

Abstract

PURPOSE: To provide a hardness meter which can move a warped test without contacting a spot anvil. CONSTITUTION: A spot anvil 5 is provided at a placement stand 4 for placing a test piece while the placement stand 4 is laid out opposite to an indenter 6. The hardness meter is provided with an upper press member 31 which is driven by a cylinder device 32 and holds and clamps the test piece to the placement stand 4 from an upper part and a lower press member 33 which is driven by a cylinder device 34 and clamps the test piece from a lower part between itself and the upper press member 31. The thrust of the cylinder device 32 is reduced as compared with that of the cylinder device 34. Therefore, while the test piece is clamped by the upper press member 31 against the placement stand 4, the lower press member 33 is driven upward by the cylinder device 34 and the test piece is clamped by the upper/lower press members 32 and 33, thus retreating the test piece upward from the spot anvil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to form an indentation on a test piece so as to sandwich the test piece between an indenter and a load receiving base, and move the test piece to measure a plurality of measurement points on the test piece. The present invention relates to a hardness meter typified by an automatic Rockwell hardness meter that can measure hardness.

[0002]

2. Description of the Related Art Conventionally known automatic Rockwell hardness testers include an indenter for applying a test load to a test piece to form an indentation on the surface thereof, and a mounting table on which the test piece is placed so as to face the indenter. And the spot anvil (load receiving part) provided on this mounting table and receiving the load from the indenter on the back side of the measurement point of the test piece, and the test piece in order to form the indentation at multiple measurement points on the test piece. And an XY stage (moving mechanism) that moves to.

When the hardness of a thin plate test piece is measured at a plurality of measuring points by using such a conventional automatic Rockwell hardness meter, the test piece is positioned so that the measuring points are located between the indenter and the spot anvil. Is placed on a test piece mounting table, the test piece is sandwiched between the upper pressing member and the mounting table, and the hardness is measured by pressing the measurement point of the test piece with an indenter. When the measurement at one location is completed, the upper pressing member is released, the test piece is moved on the XY stage, and a plurality of measurement points are sequentially opposed to the indenter, and the hardness is measured at each point.

[0004]

However, in the case of a test piece having a warp such as a test piece cut out from a thin plate material wound into a roll, the warp portion is spotted when moved on the XY stage. You may not be able to move smoothly by touching the anvil.

An object of the present invention is to provide a hardness tester capable of moving a test piece without contacting a load receiving portion called a spot anvil.

[0006]

According to the present invention, an indenter for applying a test load to a test piece to form an indentation on the surface of the test piece, and a mounting table on which the test piece is mounted so as to face the indenter, A load receiving portion provided on the mounting table and receiving a load from the indenter on the back surface of the measurement point of the test piece, and the test piece is sequentially moved to form indentations at a plurality of measurement points on the test piece. It is applied to a hardness meter having a moving mechanism. And the above-mentioned object is to press the test piece against the mounting table from above and clamp the upper pressing member, and between the upper pressing member, the lower pressing member that clamps the test piece from below, A first driving device that drives the pressing member to press it against the mounting table, and an upper pressing member that is driven by the first driving device so as to sandwich the test piece between the pressing member and the mounting table. And a second drive device which is driven in the opposite direction to the driving direction by the lower pressing member via the test piece to separate the test piece sandwiched between the upper and lower pressing members from the mounting table. Achieved by

[0007]

When changing the measurement point, when the lower pressing member is driven upward by the second drive device while the test piece is held between the upper pressing member and the mounting table, the lower pressing member becomes the upper pressing member. The test piece is sandwiched between and the test piece is lifted upward from the mounting table and the load receiving portion. In this state, the test piece is moved by the moving mechanism.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an automatic Rockwell hardness meter will be described with reference to FIGS. FIG. 1 shows the entire structure of an automatic Rockwell hardness tester, which comprises a main body 1 and an XY stage (moving mechanism) 2 installed on the main body 1.
And the test piece holder 3 mounted on the XY stage 2, and X
A test piece mounting table 4 fixedly installed on the main body 1 separately from the Y stage 2, a spot anvil (load receiving portion) 5 provided on the mounting table 4, and a plurality of indenters for forming indentations on the test piece from above. 6, an indenter switching section 7 for mounting any one of the indenters 6 against the test piece, a load detector 8 for measuring a load acting on the indenter 6, and an indenter 6 provided in the main body 1.
And an indenter drive device (not shown) for moving up and down. The plurality of indenters are, for example, steel ball indenters and conical diamond indenters.

2 to 4 are enlarged views of the peripheral portion of the XY stage 2. The XY stage 2 is a substrate 2 connected to the main body 1.
1, a step motor 22 for driving in the X direction, a step motor 23 for driving in the Y direction, both step motors 22,
23, and a moving plate 24 that moves in the XY directions. The mounting table 4 is erected on the substrate 21. A groove 4a having a rectangular cross section in a direction orthogonal to the paper surface of FIG. 3 is formed at the upper end of the mounting table 4, and a disc 5a having a spot anvil 5 protruding therefrom is fitted in the groove 4a. The spot anvil 5 receives the load of the indenter on the back surface of the test piece and prevents the test piece from being deformed.

On the moving plate 24, the cylinder device 3 of the upper pressing member 31 for sandwiching the test piece with the upper end surface of the mounting table 4.
2 and the cylinder device 34 of the lower pressing member 33 for sandwiching the test piece between the upper pressing member 31 and the upper pressing member 31. The upper presser member 31 has two presser arms 31a projecting from the main body part connected to the cylinder device 32, and the indenter 6 passes through a space 31b formed between the pair of presser arms 31a for testing. Separate and contact the measurement point on one side. The presser arm 31a holds the test piece with the mounting table 4. The lower presser member 33 has two presser arms 33a protruding from a main body portion connected to the cylinder device 34, and holds the test piece between the upper presser arm 31a and the lower presser arm 33a.

The pressure receiving area of the cylinder device 32 is made smaller than the pressure receiving area of the cylinder device 34, and the thrust of the cylinder device 34 is set to be large when receiving compressed air from the same pneumatic pressure supply source. . As a result, with the upper presser arm 31a pressing the test piece against the mounting table 4, the lower presser member 3 is pressed.
3 is moved upward by the cylinder device 34,
The test piece can be separated upward from the mounting table 4, that is, the spot anvil 5 while being held between the upper pressing arm 31a and the lower pressing arm 33a.

As best shown in FIGS. 2 and 4,
A displacement meter 41 for measuring the position of the indenter 6 to measure the depth of the indentation is attached to the side surface of the mounting table 4, and a probe 41a of the displacement meter 41 is provided upright in the space 31b. As shown in FIG. 1A, a dog 42 is provided so as to project from the lower surface of the indenter switching unit 7 so as to face the probe 41a.

The operation of the automatic Rockwell hardness tester thus constructed will be described. For example, when measuring hardness at a plurality of measurement points (indicated by crosses in FIG. 2) of a dumbbell-shaped thin plate test piece TP1, first, the test piece TP1 is conveyed by the suction type conveyance device 51 shown in FIG. The test piece TP1 is placed horizontally between the test piece holding base 3 and the mounting base 4 so that the test piece TP1 is located between the indenter 6 and the spot anvil 5. Cylinder device 3
2 is contracted and the test piece TP1 is placed on the mounting table 4 by the upper pressing member 31.
Then, the indenter 6 is pressed against the measurement point of the test piece TP1 in this state to form an indentation.

In measurement, the load is changed at one measurement point to form an indentation with the indenter 6. For example, a diamond indenter is used to measure the depth of an indentation when a load of 10 kg is applied, then the same indenter is used to apply a load of up to 100 kg, and finally a load of 10 kg is applied. Measure the depth of the indentation. Then, the Rockwell hardness is calculated by obtaining the difference between the first depth and the third depth. The load is measured by the load detector 8 and the depth is measured by the displacement meter 41.

When the Rockwell hardness at one point is obtained in this manner, the cylinder device 34 is extended to raise the lower pressing member 33, and the test piece TP1 is moved to the upper and lower pressing arms 31a, 31a.
It is clamped by 33a and retracted above the spot anvil 5 as it is. After that, the test piece TP1 held between the upper and lower presser arms 31a and 33a is moved by the XY stage 2 so that the next measurement point faces the indenter. And the cylinder device 3
4 to contract the test piece TP1 to the upper pressing member 31 and the mounting table 4
A hardness test similar to that described above is carried out in a state of being sandwiched between and. TP2 indicates a long test piece.

Since the test piece TP1 is moved after being retracted above the spot anvil 5 as described above, the test piece TP1 does not come into contact with the spot anvil 5 even if the test piece TP1 is warped. Can be moved to the correct position. Further, since the measurement points can be accurately positioned, the polishing area of the measurement points can be small, and the test preparation work time can be shortened. Furthermore, the entire process from the loading of test pieces to the measurement of multi-point hardness can be fully automated.

In the above description, the automatic Rockwell hardness meter has been described as an example. However, if the hardness meter measures the hardness by pressing the test piece between the indenter and its load receiving portion to form an indentation, it is particularly preferable. It is not limited to the Rockwell hardness tester. Further, the shape of the pressing member is not limited to the embodiment.

[0018]

As described above, according to the present invention, the test piece is clamped by the upper and lower pressing members, and the test piece is moved after the test piece is retracted above the indenter and the load receiving portion arranged in the orientation. Therefore, even a warped test piece can be moved to an accurate position without coming into contact with the load receiving portion, and a multipoint continuous automatic test becomes possible. Further, in the case of a test piece whose measurement points need to be polished, the positioning of the measurement points becomes accurate, so that the polishing area can be reduced and the pre-test preparation time can be shortened.

[Brief description of drawings]

FIG. 1 is a view showing an embodiment in which the present invention is applied to an automatic Rockwell hardness meter, (a) is a front view and (b) is a side view.

FIG. 2 is a plan view showing details around the XY stage of the automatic Rockwell hardness meter shown in FIG.

FIG. 3 is a front view of FIG. 2;

FIG. 4 is a side view of FIG.

[Explanation of symbols]

 1 main body 2 XY stage 4 mounting table 5 spot anvil 6 indenter 7 indenter switching unit 8 load detector 31 upper presser member 31a upper presser arm 32 cylinder device 33 lower presser member 33a lower presser arm 34 cylinder device 41 displacement meter 51 transfer device

Claims (1)

[Claims] 1. An indenter for applying a test load to a test piece to form an indentation on the surface thereof, a mounting table facing the indenter for mounting the test piece, and the test table provided on the mounting table. In a hardness meter having a load receiving portion that receives a load from the indenter on the back surface of the measurement point of the piece, and a moving mechanism that sequentially moves the test piece to form indentations at a plurality of measurement points on the test piece. , An upper pressing member that presses and clamps the test piece against the mounting table from above, a lower pressing member that clamps the test piece from below between the upper pressing member, and the upper pressing member. First to drive to press
Drive device and the upper pressing member driven by the first drive device so as to sandwich the test piece between the test piece and the mounting table in the direction opposite to the driving direction. And a second drive device that is driven by the lower pressing member to separate the test piece sandwiched between the upper and lower pressing members from the mounting table described above.