KR20020025432A - apparatus for correcting load cell - Google Patents

Abstract

PURPOSE: A device for correcting tension tester is provided to execute more accurate correction by impressing tension load on a tested load cell and compression load on a standard load cell. CONSTITUTION: An upper fixing plate(31) has an upper biting jaw to be installed to an upper hydraulic chuck(4) and is connected with multiple first rods(35), penetrating an upper apply plate(32) and having a lower apply plate(34) installed on lower ends thereof. A lower fixing plate(33) has a lower biting jaw to be installed to a lower hydraulic chuck(6) and is connected with multiple second rods(36), penetrating the lower apply plate and having the upper apply plate installed on upper ends thereof. A standard load cell(15) compared with a tested load cell(3) is placed between the upper and the lower apply plates.

Description

Tension Tester Calibration Device {apparatus for correcting load cell}

The present invention relates to a device for calibrating a tensile tester, and more specifically, to a test load shell calibration operation for the reference load shell while applying a compressive load to the reference load cell, the tensile load in the same direction as the specimen tension test operation to the test load cell The present invention relates to a tension tester calibration apparatus capable of performing a more precise calibration by performing a calibration operation.

In general, as shown in Figure 1, the load detection device, which is an important sensor for testing the tension of the test piece 5, is a load shell (3) is coupled to the tensile tester (1) as a load shell (3) during the tensile test Is a detector that detects the mechanical deformation obtained in the N-axis and converts it numerically or so as to display a graph as shown in FIG.

That is, the specimen to be tested is manufactured according to the test standard (KS, JIS, DIN, ASTM), and the specimen 5 is bitten between the upper hydraulic chuck 4 and the lower hydraulic chuck 6 of the tensile tester 1. Then, the tension test is started when the upper crosshead 2 is moved upward with respect to the fixed upper fixing frame 2a by rotating the ball screw 1 by mechanical driving inside the lower frame base 7. Accordingly, deformation occurs in the specimen 5 to initiate a tensile test.

At this time, it should be a structure to bite the specimen (5) by applying a force so that slip does not occur in the bite portion of the specimen (5), typically using a hydraulic force, if the fracture occurs in the specimen (5) during the test The crosshead 2 should stop automatically.

On the other hand, the rod between the upper hydraulic chuck (4) and the upper crosshead (2) holding the upper portion of the specimen (5) in order to know how much force is applied when the upper portion of the specimen (5) is pulled upwards Install the shell (3) and measure the load value.

In other words, when the upper and lower portions of the specimen 5 are bitten, the load value of the load shell 3 appears as a negative value, which is not obtained as data, but by applying a pre-load, the load value is zero. The test will then begin.

When the specimen 5 is slowly pulled at the specified speed according to the test standard, the yield strength value is obtained at the elastic limit point of the specimen 5, and if the tension is continuously continued, the maximum load value of the specimen 5 can be obtained. The equipment is operated to stop the test by measuring the load change when the specimen (5) is broken, and after the test is slightly different depending on the material of the specimen, but in the case of ordinary steel, yield strength (10), yield stretching (11), a graph showing the maximum tensile strength (12) is drawn.

The load cell (3), which is an important sensor used for the specimen tension test, is inspected once a year to meet the accuracy test standard, and if it is not within ± 1%, the accuracy is adjusted to within ± 1% by adjusting it. Should be maintained

Currently, the JIS standard is required to be precise enough that there is a movement to be strictly applied within ± 0.5%, and since the quality of all materials is being advanced day by day, the strict quality management is required and all conditions are the same. Only then can you achieve reliability.

On the other hand, the accuracy test operation for the calibration of the conventional load cell (3), as shown in Figure 3, to perform the compression-type calibration to press the load cell (3) downward to correct the direction opposite to the tensile test direction for the specimen (5) It was.

That is, the upper calibration plate 14 is mounted on the upper hydraulic chuck 4, and the lower calibration plate 16 corresponding thereto is mounted on the lower hydraulic chuck 6 so that the upper and lower calibration plates 14 and 16 are mounted. The load value measured in the reference rod shell 15 and the upper hydraulic chuck 4 are lowered by lowering the upper crosshead 2 to the lower side as opposed to the specimen tension test with the calibration reference rod shell 15 disposed therebetween. ) And the degree of the test load shell 3 was calibrated to meet the reference value while comparing the load values measured in the test load shell 3 disposed between the top crosshead 12 and the top crosshead 12.

At this time, the data measured by the conventional calibration method is shown in Table 1 below.

Standard capacity Actual load (KG.F) Measured value (KG.F) error(%) 0.2 tons 40.00 40.31 0.77 80.00 80.63 0.78 120.00 120.83 0.68 0.5 tons 100.00 100.64 0.65 200.00 201.35 0.67 300.00 301.95 0.65 1.0 ton 200.00 201.56 0.61 400.00 402.56 0.64 600.00 603.28 0.54 2.0 tons 400.00 402.35 0.58 800.00 804.46 0.55 1200.00 1207.81 0.65

However, as shown in Table 1, the transfer process of the load applied to the load shell 3 during the tensile test and the transfer direction of the load applied during compression extend in the opposite direction to the load shell 3. When the test rod shell 3 is calibrated with respect to the reference rod shell 15, the error exceeds the range of ± 0.5, and the reliability thereof decreases, and accurate test data cannot be obtained, so that precise calibration cannot be performed. there was.

Accordingly, the present invention has been made in view of such a conventional problem, and an object thereof is to apply a tensile load to a test load shell in the same direction as a specimen tension test operation for calibrating a test load shell with respect to a reference load shell. At the same time, to provide a tension tester calibration device that can perform a more precise calibration by performing a calibration operation while applying a compressive load to the reference load cell.

1 is a schematic view showing a typical specimen tensile tester,

2 is a graph showing the values obtained using a typical specimen tensile tester,

3 is a schematic diagram showing the operation of calibrating the tensile tester according to the prior art,

Figure 4 is an exploded perspective view showing a tension tester calibration apparatus according to the present invention,

5 is an overall perspective view showing a tension tester calibration apparatus according to the present invention.

Explanation of symbols on the main parts of the drawings

2 .... Upper crosshead 3 .... Test load shell

4 .... Upper hydraulic chuck 5 .... Specimen

6 .... Lower hydraulic chuck 7 .... Lower frame

8 .... Ball screw 15 ... Standard load shell

31 ... upper fixing plate 32 ... upper applying plate

33 ... lower mounting plate 34 ... lower mounting plate

35 ... First Load 36 ... Second Load

As a technical configuration for achieving the above object, the present invention,

An upper cross head which is lowered and lowered in accordance with the rotation direction of a plurality of ball screws vertically installed on the lower frame base, upper and lower hydraulic chucks each of which is fixed by biting the upper and lower ends of the specimen, and between the upper hydraulic chuck and the upper cross head. In a facility having a test rod shell disposed therein for performing a tensile test on a specimen,

The upper fixing plate having an upper chuck jaw to be mounted on the upper hydraulic chuck is connected to a plurality of first rods equipped with a lower applying plate at the lower end passing through the upper applying plate, and the lower bite can be mounted on the lower hydraulic chuck. The lower fixing plate having the jaw is connected to a plurality of second rods in which the upper applying plate is mounted at the upper end passing through the lower applying plate, while the reference rod is compared with the test rod shell between the upper and lower applying plates. By providing a calibration apparatus for accredited testers characterized in that the load shell is provided.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

Figure 4 is an exploded perspective view showing a tension tester calibration apparatus according to the present invention, Figure 5 is a full perspective view showing a tension tester calibration apparatus according to the present invention.

4 and 5, the calibration device 100 of the present invention, the upper and lowered in accordance with the rotational direction of the lower hydraulic chuck 6 and the ball screw 8 fixed to the lower frame base (7) The test load cell 3 and the reference load shell 15 are placed between the crosshead 2 and the upper hydraulic chuck 4 which is moved and apply a load in the same direction as the operating direction of the tensile test of the specimen 5. As a calibration to improve the accuracy of the test rod shell (3) used in the tensile test in comparison, such a calibration device 100 is fixed to the upper, the application plate 31, 32, the lower fixing, the application plate 33 ( 34 and first and second rods 35 and 36.

That is, the upper fixing plate 31 is a rectangular plate member which is replaceably mounted as a bolt member not shown in the upper chuck 31a at the center of the upper surface so that it can be firmly mounted on the upper hydraulic chuck (4), Opposite diagonal edges of the upper fixing plate 31 are integrally connected with upper ends of the plurality of first rods 35 passing through the diagonal edges of the upper application plate 32 and integrally connected to the lower edges thereof. The diagonal edges of the lower application plate 34 are each integrally connected.

In addition, the lower fixing plate 33 is a rectangular plate member having a lower chuck 33a at the center of the lower surface so as to be fixed to the lower hydraulic chuck 6 so as to be replaced as a bolt member not shown. Opposing diagonal edges of the lower fixing plate 33 connect lower ends of the plurality of second rods 36 passing through the remaining diagonal edges of the lower application plate 34 on which the first rod 35 is not disposed. The upper end plate 32 is integrally connected to the upper end portion thereof.

Accordingly, the upper hydraulic pressure relative to the lower fixing plate 33, the second rod 36, and the upper applying plate 32, which are connected to the lower hydraulic chuck 6, which is positioned when the upper hydraulic chuck 4 rises. As the upper fixing plate 31, the second rod 35, and the lower applying plate 34 connected to the chuck 4 are raised, the interval between the upper and lower applying plates 32 and 34 is narrowed. .

In addition, between the upper and lower application plates 32 and 34, a reference load can be compared with the test load shell 3 disposed between the upper crosshead 2 and the upper hydraulic chuck 4 and the measured load value. The load shell 15 is provided and comprised.

Here, the first and second rods 35 and 36 are preferably provided with chrome plated rod members so as to prevent bending or deformation during the calibration operation to transmit the compression and tensile loads. ) Slides vertically in the through hole (not shown) of the upper application plate 32 through which the second connection 36 is connected, and the through hole (not shown) of the lower application plate 34 through which the second rod 36 is connected. A sliding member such as a bushing member may be provided so as to smoothly accomplish this.

The operation and effects of the present invention as described above will be described.

First, the upper and lower chuck 31a of the upper fixing plate 31 is attached to the upper and lower hydraulic chucks 4 and 6 while the specimen 5 between the upper and lower hydraulic chucks 4 and 6 is removed. And, after arranging the lower bleeding jaw (33a) of the lower fixing plate 33, respectively, and then applying the hydraulic pressure through the hydraulic pipe (4a), the upper and lower fixing plates 31, 33 are firmly mounted.

In this state, the lower applying plate 34 connected through the upper fixing plate 31 and the first rod 35 and the upper connecting plate via the lower fixing plate 33 and the second rod 36. By placing the reference rod shell 15 between the application plates 32 and then operating the motor member (not shown) in the lower frame base 7 in the same manner as in the tensile test on the specimen 5, the power transmission means ( When the ball screw 8 is rotated in the forward direction through the ball screw 8, the upper cross head 2 assembled to the ball screw 8 is proportional to the rotation amount of the ball screw 8 along the guide rod 8 a. To move upward.

And, as the upper crosshead 2 rises and the upper hydraulic chuck 4 connected thereto is also raised, the upper fixing plate 31 mounted thereon is moved up and down, thus being mounted and fixed on the lower hydraulic chuck 6 The upper fixing plate 31, the first rod 35, and the lower applying plate 34 by moving the lower fixing plate 33, the second rod 36, and the upper applying plate 32 up to the reference. The gap between the upper and lower application plates 32 and 34 on which the load shell 15 is disposed is narrowed. Accordingly, the reference rod shell 15 measures the load value to which the compressive load is transmitted and applied when its upper end is in contact with the lower surface of the upper application plate 32.

This is because the first rod 35 facing in the diagonal direction is assembled so as to be movable through the upper applying plate 32, and the second rod 36 facing in the diagonal direction is the lower applying plate 34. It is possible because the upper part of the reference rod shell 15 can be brought into close contact with the upper application plate 32 so as to be assembled therethrough.

In addition, the compressive load is transmitted to the reference rod shell 15 and the test rod shell 3 disposed between the upper hydraulic chuck 4 and the upper cross head 2 is similar to the tensile test of the specimen 5. The tensile load is transmitted to measure the applied load value.

Therefore, the test rod shell obtained by applying the tensile load, such as when performing a tensile test on the specimen and the load value of the reference rod shell 15 obtained by applying a compressive load as when the test in the standard engine ( The test load shell 3 can be calibrated to be within the reference value while comparing the load values of 3) with each other.

Here, Table 2 shows the data obtained during the operation of applying the tensile load to the test load shell in the present invention to calibrate.

Standard capacity Actual load (KG.F) Measured value (KG.F) error(%) 0.2 tons 40.00 40.12 0.30 80.00 80.32 0.40 120.00 120.43 0.35 0.5 tons 100.00 100.45 0.45 200.00 200.84 0.42 300.00 301.45 0.48 1.0 ton 200.00 200.79 0.39 400.00 401.39 0.34 600.00 602.62 0.43 2.0 tons 400.00 401.27 0.31 800.00 802.89 0.36 1200.00 1204.93 0.41

As shown in Table 2, it can be seen that the error range comparing the actual load and the measured load value can be within ± 0.5 range, so that more accurate calibration can be performed by comparing with Table 1 obtained by the conventional calibration.

According to the present invention having the configuration as described above, in the calibration operation of the test load shell used for the tensile test, the reference load shell applies the compressive load in the same manner as when the standard engine is tested, and the test load shell is As it is possible to perform the calibration work by applying the tensile load in the same way as the specimen tension test, accurate and reliable data can be obtained, and the rod shell can be calibrated with higher precision than the conventional one. The effect that can be performed is obtained.

While the invention has been shown and described with respect to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit or scope of the invention as set forth in the claims below. I would like to clarify that knowledge is easy to know.

Claims (2)

Upper and lower crossheads 2 and 2 and the upper and lower ends of the test piece 5 which are vertically lowered in accordance with the rotational direction of the plurality of ball screws 8 installed perpendicular to the lower frame base 7 are fixed. In a facility for performing a tensile test on the specimen (5) having a hydraulic chuck (4) (6) and a test rod shell (3) disposed between the upper hydraulic chuck (4) and the upper crosshead (2) , The upper fixing plate 31 having the upper chuck 31a so as to be mounted on the upper hydraulic chuck 4 includes a plurality of first rods on which a lower applying plate 34 is mounted at a lower end of the upper applying plate 32. The lower fixing plate 32 having a lower engagement jaw 32a so as to be connected to the lower hydraulic chuck 6 and configured to be connected to the lower hydraulic chuck 6 is the upper application plate at an upper end portion passing through the lower application plate 34. A reference rod shell 15 which is configured to be connected to a plurality of second rods 36 equipped with 23 and is compared with the test rod shell 3 between the upper and lower application plates 32 and 34. Accredited tester calibration device characterized in that the configuration. The method of claim 1, The first rod 35 is arranged in pairs at the corners of the upper fixing plate 31 in the diagonal direction, and the second rod 36 is in the diagonal direction of the lower fixing plate 32 crossing the diagonal direction. Accreditation tester calibration device, characterized in that arranged in pairs at the corner.