JP7414023B2 - test equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a testing device.

BACKGROUND ART Conventionally, a material testing device is known that performs a bending test by applying a test force to a test piece supported by a pair of fulcrums. In such a test device, a load is applied to a test piece by pushing an indenter into the test piece from above. The test force applied to the test piece is detected by a load cell provided in the indenter (see, for example, Patent Document 1).

Additionally, such testing equipment uses a contact-type displacement detector that detects the displacement that occurs in a test piece when an indenter is pushed into the test piece by touching the tip of the probe to the center of the test piece. What is known is known.
Such a probe sandwiches the test piece and abuts against the test piece at a position opposite to the indenter. Additionally, the probe is supported by a spring member that resiliently biases it toward the test specimen.

Japanese Patent Application Publication No. 2012-251901

However, in the conventional configuration, the spring member is compressed by the test force applied by the indenter to the test piece, and repulsive energy is stored in the spring member. For this reason, as the amount of displacement of the test piece increases, there is a possibility that the error included in the detected value of the load cell will increase.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a test device that can detect test force with higher accuracy.

A first aspect of the present invention is a test device that performs a test for detecting the amount of displacement caused by applying a test force to a test piece, in which a cross head that is moved by a loading mechanism is provided with a an indenter for applying a test force to the test piece; a load detector provided on the crosshead for detecting the test force applied to the test piece; a displacement detector that detects the amount of displacement of the test piece caused by the application of a test force from the amount of movement of the probe, and the probe and the indenter; The present invention relates to a test device including a biasing member that biases the probe so that the probe is brought into contact with the probe sandwiched therebetween.

According to the first aspect of the present invention, the probe is supported by the indenter by the biasing member. This suppresses the force that supports the probe from being applied to the load detector.
Therefore, the test force can be detected with higher accuracy.

FIG. 1 is a diagram schematically showing a test device according to the present embodiment. FIG. 3 is a diagram schematically showing the configuration of the inside of a thermostatic chamber and a displacement detection section when starting a test. FIG. 3 is a diagram schematically showing the configuration of a displacement detector.

[1. Configuration of test equipment]
[1-1. Overall configuration of test equipment]
The present embodiment will be described below with reference to the drawings.
FIG. 1 is a diagram schematically showing a test apparatus 1 according to the present embodiment. In addition, in FIG. 1, for convenience of explanation, the constant temperature bath 3 is shown by a chain line.
The test apparatus 1 of this embodiment applies a test force F to the test piece TP and performs a bending test to measure mechanical properties such as bending strength, yield point, and deflection of the sample. The test force F is a pressing force.
The test device 1 includes a test device main body 2 that performs a bending test by applying a test force F to a test piece TP, which is the material to be tested, a constant temperature chamber 3, a control of the bending test operation by the test device main body 2, and a constant temperature bath. 3, a control unit 4 that performs temperature control.

The test device main body 2 includes a table 26, a pair of screw rods 28 and 29 rotatably erected vertically on the table 26, and movable along these screw rods 28 and 29. It includes a crosshead 10, a load mechanism 12 that moves the crosshead 10 to apply a load to the test piece TP, and a load cell 14. The load cell 14 is a sensor that measures a test force F, which is a pressing load applied to the test piece TP, and outputs a test force measurement signal SG1.

The load mechanism 12 includes worm reducers 16 and 17 connected to the lower ends of each screw rod 28 and 29, a servo motor 18 connected to each worm reducer 16 and 17, and a rotary encoder 20. The rotary encoder 20 is a sensor that measures the amount of rotation of the servo motor 18 and outputs to the control unit 4 a rotation measurement signal SG2 with a number of pulses corresponding to the amount of rotation.
The load mechanism 12 transmits the rotation of the servo motor 18 to the pair of screw rods 28 and 29 via the worm reducers 16 and 17, and each screw rod 28 and 29 rotates in synchronization, so that the crosshead 10 moves up and down along the screw rods 28 and 29.

The constant temperature bath 3 is a housing whose sides are covered with heat insulating walls. In this embodiment, the constant temperature bath 3 is arranged between each of the screw rods 28 and 29, and between the crosshead 10 and the table 26. Further, the constant temperature bath 3 is located above the table 26, away from the top surface of the table 26.
The constant temperature bath 3 has a space S in which the test piece TP is housed, and the temperature within the space S can be controlled. Note that the test apparatus 1 is not limited to this, and the test apparatus 1 may be provided with various test tanks such as a constant humidity chamber that can control humidity, a constant temperature and humidity chamber that can control both temperature and humidity. Further, the constant temperature bath 3 may be provided with various temperature testing devices.

A pair of fulcrums 22 are provided on the bottom wall of the constant temperature bath 3. These fulcrums 22 are formed into columnar shapes extending upward from the bottom wall of the thermostatic chamber 3 . The pair of fulcrums 22 are provided along the longitudinal direction of the crosshead 10 so that the distance between them (the distance between the fulcrums) can be changed.
The test piece TP is placed on the upper ends of the pair of supporting points 22 in the space S. That is, the pair of fulcrums 22 support the test piece TP from the bottom. The longitudinal direction of the test piece TP supported by the pair of fulcrums 22 is arranged along the longitudinal direction of the crosshead 10.

Through holes 23 and 24 are provided in both the top wall and the bottom wall of the constant temperature bath 3. These through holes 23 and 24 are provided at positions facing each other.

As described above, the crosshead 10 is provided with the load cell 14, which is a load detector that detects the test force F applied to the test piece TP, and the indenter 21 that comes into contact with the surface of the test piece TP.
The load cell 14 is formed into a columnar shape having a predetermined length extending downward from the bottom surface of the crosshead 10 along the vertical direction.
In this embodiment, the load cell 14 is inserted into the through hole 23, and the lower end side is arranged in the space S of the thermostatic oven 3. Note that the load cell 14 is not limited to this, and the entire load cell 14 may be placed outside the thermostatic chamber 3.

The indenter 21 is provided at the lower end of the load cell 14. This indenter 21 is a member whose lower end comes into contact with the upper surface (one surface) of the test piece TP when a bending test is performed. In this embodiment, the indenter 21 contacts the longitudinal center of the test piece TP when a bending test is performed. Further, the indenter 21 is inserted into the through hole 23, and at least the lower end thereof is arranged in the space S of the thermostatic oven 3.
This indenter 21 is provided with a connecting member 25 at a location located above the lower end of the indenter 21 . This connecting member 25 is a flat member extending along the longitudinal direction of the crosshead 10.

A support stand 27 is provided on the table 26 at a position facing the load cell 14 . A through hole 39 is provided on the upper surface of this support base 27 . Further, a displacement detection section 30 is provided on the upper surface of the support base 27. This displacement detection section 30 measures the deflection of the central portion of the test piece TP using a contact method.

The control unit 4 takes in test force data from the load cell 14 and data from the displacement detection section 30, and executes data processing. Through processing such as calculation in the control unit 4, the test force F (bending load) on the test piece TP and the deflection on the test piece TP are determined.

The control unit 4 includes a computer having a processor such as a CPU or an MPU, and a memory device such as a ROM or a RAM, and controls each part of the test apparatus main body 2 and the constant temperature oven 3.

The control unit 4 is connected to the test apparatus main body 2 and the thermostatic chamber 3 so as to be able to transmit and receive signals. The signals received from the test device main body 2 include a test force measurement signal SG1 outputted by the load cell 14, a rotation measurement signal SG2 outputted by the rotary encoder 20, an elongation measurement signal SG3 outputted by the displacement sensor 15, and appropriate signals required for control and testing. signals, etc. Further, the signals received from the constant temperature oven 3 are appropriate signals required for controlling and testing the constant temperature oven 3.
The control unit 4 takes in test force data from the load cell 14 and data from the displacement detector 40, and executes data processing.

The control unit 4 accepts user operations such as setting various setting parameters such as test conditions for bending tests, or execution instruction operations, and has the function of outputting to the test apparatus main body 2 and thermostatic chamber 3, and outputting test force measurement values. It has functions such as data analysis.

[1-2. Configuration of displacement detection section]
Next, the configuration of the displacement detection section 30 will be explained.
FIG. 2 is a diagram schematically showing the configuration of the inside of the thermostatic chamber 3 and the displacement detection section 30 when starting a test. In addition, in FIG. 2, for convenience of explanation, the constant temperature bath 3 is shown by a chain line.
As described above, the displacement detection section 30 is attached to the testing apparatus 1 for bending tests, and measures the deflection of the central portion of the test piece TP in a contact manner. As shown in FIG. 2, the displacement detection unit 30 includes a probe 32 that is inserted into the through hole 24 and is provided so as to be movable along the axial direction of the load applied by the indenter 21, and a displacement detector 40 that is connected to the probe 32. Equipped with. The displacement detector 40 is placed outside the thermostatic chamber 3, as shown in FIG.

The probe 32 includes a shaft portion 34, a tip portion 36, and a connecting member 38.
The shaft portion 34 is a rod-shaped member that extends along the axial direction of the load applied by the indenter 21 . This shaft portion 34 is inserted into the through hole 24. Further, the lower end of the shaft portion 34 is inserted into the through hole 39 of the support base 27 .
The tip portion 36 is provided at the upper end of the shaft portion 34 . This tip portion 36 is a columnar member with a larger diameter than the shaft portion 34 .
The connecting member 38, like the connecting member 25, is a flat member extending along the longitudinal direction of the crosshead 10. A through hole 39 having a larger diameter than the shaft portion 34 and a smaller diameter than the tip portion 36 is provided in the center of the flat plate portion of the connecting member 38 .
In the probe 32, the upper end of the shaft portion 34 is inserted into the through hole 39, and the lower end of the tip portion 36 comes into contact with the flat plate portion of the connecting member 38.

In the test apparatus 1 of this embodiment, the connecting member 25 and the connecting member 38 are connected by a plurality of spring members 50.
These spring members 50 are an example of a biasing member, and the spring members 50 are so-called tension springs. Each of these spring members 50 has one end connected to the lower surface of the flat plate portion of the connecting member 25 and the other end connected to the upper surface of the flat plate portion of the connecting member 38.
In this embodiment, the spring members 50 are provided one on each side of the indenter 21 along the longitudinal direction of the crosshead 10, and one on each side of the indenter 21 along the width direction of the crosshead 10. There will be a total of four locations.
As a result, the probe 32 is suspended from the indenter 21 via each spring member 50. In other words, the probe 32 is supported by the indenter 21.

Further, as described above, since each spring member 50 is a tension spring, the probe 32 is biased toward the indenter 21. When the test piece TP is not placed on the fulcrum 22, the tip of the tip portion 36 of the probe 32 comes into contact with the lower end of the indenter 21 due to the urging force of these spring members 50.

When the test piece TP is placed on the fulcrum 22, each spring member 50 is expanded to separate the tip of the tip 36 of the probe 32 and the lower end of the indenter 21, and be placed between. Thereafter, the probe 32 is pulled up by the biasing force of each spring member 50, the lower end of the indenter 21 contacts the upper surface of the test piece TP, and the upper end of the tip 36 contacts the lower surface (other surface) of the test piece TP. .
Thereby, the test piece TP is supported by the fulcrum 22 and held between the indenter 21 and the probe 32.

[1-2. Configuration of displacement detector]
Next, the configuration of the displacement detector 40 will be explained.
FIG. 3 is a diagram schematically showing the configuration of the displacement detector 40.
As shown in FIG. 3, the displacement detector 40 includes a displacement detector main body 42, a spindle 44, and a moving body 47.

The displacement detector main body 42 is provided with an insertion hole 46, into which a spindle 44, which is a columnar member having a predetermined length, is inserted. This insertion hole 46 extends along the moving direction of the shaft portion 34, that is, the load axis direction of the indenter 21, and the lower end side of the insertion hole 46 is open.

The spindle 44 is inserted into the insertion hole 46 from an opening on the lower end side of the insertion hole 46 . This spindle 44 is movable up and down along the insertion hole 46.
The displacement detector main body 42 is equipped with a linear scale. The displacement detector main body 42 detects the amount of movement of the spindle 44 moving inside the insertion hole 46 using this linear scale.
The displacement detector main body 42 outputs the detected movement amount to the control unit 4 as data.
Note that as the displacement detection means for the spindle 44 included in the displacement detector main body 42, other methods such as a differential transformer method may be adopted, for example.
This displacement detector main body 42 is supported by, for example, a support base 27.

The lower end of the spindle 44 is supported by a moving body 47.
This moving body 47 is provided integrally with the shaft portion 34 and moves together with the shaft portion 34 .
The spindle 44 is supported by this moving body 47 from the lower end.

[2. Effect]
Next, the operation of this embodiment will be explained.
When starting a test using the test apparatus 1, the test piece TP is supported by the fulcrum 22 and held between the indenter 21 and the probe 32.
In this state, zero point adjustment is performed on the load cell 14 and the displacement detector main body 42.
Thereafter, by lowering the crosshead 10, a test force F (bending load) is applied to the test piece TP. In this case, the test force F acting on the test piece TP is detected by the load cell 14 and input to the control unit 4.

When the crosshead 10 is lowered, the test piece TP is bent, and the probe 32 is lowered along the axial direction of the load applied by the indenter 21 while maintaining a distance from the lower end of the indenter 21.
As described above, since the probe 32 is supported by the indenter 21 by being suspended from the indenter 21, the force for supporting the probe 32 is suppressed from being applied to the load cell 14. Therefore, the test device 1 can detect the test force F acting on the test piece TP with higher accuracy.

When the probe 32 descends, the movable body 47 descends together with the probe 32. That is, the movable body 47 supporting the spindle 44 is lowered, and the spindle 44 moves vertically downward together with the movable body.
The displacement detector body 42 detects the amount of movement of the spindle 44, and the detected amount of movement is detected as the deflection of the test piece TP. The displacement detector main body 42 outputs the detected deflection to the control unit 4 as data.

In this way, the spindle 44 is supported by the movable body 47 and is configured to move vertically downward together with the movable body 47, which is moved by the bending of the test piece TP. This prevents the force that supports the spindle 44 from being applied to the displacement detector main body 42. Therefore, the test apparatus 1 can detect the deflection occurring in the test piece TP with higher accuracy.

As described above, the displacement detector 40 is placed outside the thermostatic chamber 3. As a result, the displacement detector 40 is not affected by the temperature control of the constant temperature bath 3, and a decrease in accuracy due to temperature drift or the like is suppressed. Therefore, the displacement detector 40 can be used in the test apparatus 1, for example, without improving heat resistance.

Furthermore, since the displacement detector 40 is placed outside the constant temperature bath 3, a predetermined distance is provided between the displacement detector 40 and the test piece TP placed inside the constant temperature bath 3. For this reason, in the test apparatus 1 of this embodiment, the length dimension of the shaft portion 34 of the probe 32 becomes long. That is, in the test apparatus 1, the number of heavier probes 32 increases.

Even in such a case, since the probe 32 is supported by the indenter 21 by being suspended from the indenter 21, the force for supporting the probe 32 is suppressed from being applied to the load cell 14. As a result, the test device 1 can detect the test force F acting on the test piece TP with high accuracy even when using the displacement detector 40 equipped with the probe 32 having a long length dimension. .

Furthermore, since the displacement detector 40 is a contact type, even when installed with a predetermined distance between it and the test piece TP, it is more effective than using a non-contact type displacement detector, for example. The test force F acting on the test piece TP can be detected with high accuracy.
As described above, the testing device 1 of the present embodiment is suitable for determining the plastic bending properties specified in JIS_K7161, and the extensometer verification method used in the axial test specified in JIS_B7741 grade 1. The test force F acting on the test piece TP can be detected with an accuracy that satisfies Class 1.

The control unit 4 takes in test force data from the load cell 14 and data from the displacement detector main body 42, and executes data processing. Through processing such as calculation in the control unit 4, the test force F (bending load) on the test piece TP and the deflection on the test piece TP are determined in the test apparatus 1.

[3. effect]
As described above, according to the present embodiment, the testing apparatus 1 performs a test to detect the amount of displacement caused by applying the test force F to the test piece TP. The test apparatus 1 includes an indenter 21 that is provided on a crosshead 10 that is moved by a load mechanism 12 and applies a test force F to one surface of the test piece TP, and an indenter 21 that is provided on the crosshead 10 and applies a test force F to one side of the test piece TP. A load cell 14 for detecting F is provided. The test apparatus 1 also includes a probe 32 disposed at a position facing the indenter 21 with the test piece TP in between, and a displacement of the test piece TP caused by applying a test force F from the movement amount of the probe 32. It may also include a displacement detector 40 that detects the amount, and a spring member 50 that connects the probe 32 and the indenter 21 and urges the probe 32 to come into contact with the indenter 21 across the test piece TP. .

According to this, since the probe 32 is supported by the indenter 21 by being suspended from the indenter 21, the force for supporting the probe 32 is suppressed from being applied to the load cell 14. Therefore, the test device 1 can detect the test force F acting on the test piece TP with higher accuracy.

Further, according to the present embodiment, the displacement detector 40 includes a spindle 44 that moves with the movement of the probe 32, and the amount of the test piece TP generated by applying the test force F from the amount of movement of the spindle 44. Detect the amount of displacement. Then, when the test force F is applied to the test piece TP, the spindle 44 may move vertically downward.

According to this, the force that supports the spindle 44 is suppressed from being applied to the displacement detector main body 42. Therefore, the test apparatus 1 can detect the deflection occurring in the test piece TP with higher accuracy.

Further, according to the present embodiment, the thermostatic chamber 3 in which the test piece TP, the indenter 21, and the probe 32 are stored may be provided, and the displacement detector 40 may be provided outside the thermostatic chamber 3.

According to this, it is possible to suppress the temperature of the constant temperature bath 3 from acting on the displacement detector 40. Therefore, the test apparatus 1 can detect the deflection occurring in the test piece TP with higher accuracy.

Further, according to the present embodiment, the indenter 21 and the probe 32 may be connected by the spring member 50.

According to this, in the test apparatus 1, the indenter 21 and the probe 32 can be easily separated from each other, and the test piece TP can be held between them. Moreover, the test apparatus 1 can easily hold various test pieces TP having different thicknesses.

[4. Other embodiments]
The embodiment described above is an example of one aspect of the present invention, and can be arbitrarily modified and applied without departing from the spirit of the present invention.

In the embodiment described above, the connection member 25 is provided on the indenter 21, but the connection member 25 is not limited to this, and the connection member 25 may be provided on the load cell 14.

Further, in the embodiment described above, the spring member 50 is used as the biasing member, but the present invention is not limited to this, and other members such as a linearly formed rubber member or a belt-like member equipped with a belt mechanism may be used. There may be.

It will be understood by those skilled in the art that the exemplary embodiments and variations described above are specific examples of the following aspects.

(Section 1)
A test device according to one embodiment is a test device that performs a test to detect the amount of displacement caused by applying a test force to a test piece, and is provided on a crosshead that moves by a loading mechanism, and is provided on a crosshead that moves by a loading mechanism, and is provided on a crosshead that moves by a loading mechanism. an indenter that applies a test force, a load detector that is provided on the crosshead and that detects the test force applied to the test piece, and a load detector that is placed at a position facing the indenter with the test piece in between. A probe, a displacement detector that detects the amount of displacement of the test piece caused by applying a test force from the amount of movement of the probe, and the probe and the indenter are connected, and the test piece is connected to the indenter. and a biasing member that biases the probe so as to sandwich and abut the probe.

According to the test device described in item 1, the probe is supported by the indenter by being suspended from the indenter, so that the force for supporting the probe is suppressed from being applied to the load cell. Therefore, the test device can detect the test force acting on the test piece with higher accuracy.

(Section 2)
In the test device according to item 1, the displacement detector includes a spindle that moves with the movement of the probe, and the displacement of the test piece caused by applying a test force from the amount of movement of the spindle. The spindle may move vertically downward when a test force is applied to the test piece.

According to the test device described in item 2, the probe is supported by the indenter by being suspended from the indenter, so that the force for supporting the probe is suppressed from being applied to the load cell. Therefore, the test device can detect the test force acting on the test piece with higher accuracy.

(Section 3)
The test apparatus according to item 1 or 2, further comprising a thermostatic chamber in which the test piece, the indenter, and the probe are housed, and the displacement detector may be provided outside the thermostatic chamber. good.

According to the test device described in item 3, it is possible to suppress the temperature of the constant temperature bath from acting on the displacement detector. Therefore, the test device can detect deflection occurring in the test piece with higher accuracy.

(Section 4)
In the test device according to items 1 to 3, the biasing member may be a spring member.

According to the test device described in item 4, the indenter and the probe can be easily separated from each other, and the test piece can be held between them. Further, the test device can easily hold various test pieces having different thicknesses.

1 Test device 2 Test device main body 3 Constant temperature chamber 10 Crosshead 12 Load mechanism 14 Load cell (load detector)
15 Displacement sensor 21 Indenter 30 Displacement detection part 32 Probe 34 Shaft part 36 Tip part 38 Connection member 40 Displacement detector 42 Displacement detector main body 44 Spindle 47 Moving body 50 Spring member F Test force TP Test piece

Claims (4)

In a test device that performs a test to detect the amount of displacement caused by applying a test force to a test piece,
an indenter provided on a crosshead that is moved by a load mechanism and applies a test force to one side of the test piece; a load detector provided on the crosshead and configured to detect the test force applied to the test piece;
a probe disposed at a position facing the indenter with the test piece sandwiched therebetween;
a displacement detector that detects the amount of displacement of the test piece caused by the application of a test force from the amount of movement of the probe; and a displacement detector that connects the probe and the indenter, sandwiching the test piece with respect to the indenter. a biasing member that biases the probe so as to come into contact with the probe;
Test equipment. The displacement detector includes a spindle that moves with the movement of the probe, and detects the amount of displacement of the test piece caused by applying a test force from the amount of movement of the spindle,
The spindle moves vertically downward when a test force is applied to the test piece.
The test device according to claim 1. comprising a thermostatic chamber in which the test piece, the indenter, and the probe are housed;
The displacement detector is provided outside the thermostatic chamber,
The test device according to claim 1 or claim 2. The biasing member is a spring member.
A test device according to any one of claims 1 to 3.

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