JPH0479530B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a material testing machine that applies torsional load and tensile or compressive load to a test piece.

(B) Prior Art For example, when testing a material on a test piece, a torque actuator applies torque, that is, a torsional load, to the test piece. At the same time, an axial force actuator applies an axial force, ie, a tensile or compressive load, to the specimen, allowing the specimen to be subjected to a combination stress test. The specimen can also be subjected to alternating torques and alternating axial forces. Furthermore, it is also possible to detect the torque and axial force of the test piece using a torque axial force detector, such as a torque axial force cell, and to feedback control the torque actuator and axial force actuator using a closed loop control circuit. be. The feedback control circuit takes out the torque detection output and the axial force detection output of the torque axial force detector and applies them to the torque actuator and the axial force actuator. As a result, the torque actuator and the axial force actuator are feedback-controlled, and torque and axial force are applied according to the setting signal of the function generator.

However, in this case, there is a problem that mutual interference occurs between the torque detection output and the axial force detection output of the torque axial force detector, and this affects the feedback control of the torque actuator and the axial force actuator. For example, even if only an axial force is applied to the test piece, in addition to the axial force detection output of the detector, a considerable torque detection output is generated due to mutual interference. This is applied to the torque actuator.
Therefore, the torque actuator is driven by the closed loop control circuit to apply an alternating torque to the test specimen. Similarly, even if only torque is applied to the test piece, an axial force detection output will be generated on the detector,
An alternating axial force is applied to the specimen. For this reason, it was not possible to accurately test the strength of the test piece against axial force and torque. Furthermore, when alternating torque and alternating axial force are applied to the test piece, it is inevitable that an output error will occur in the torque detection output and the axial force detection output due to mutual interference. Furthermore, mutual interference occurs with respect to this output error, resulting in a double output error. When applying the rated torque and rated axial force, an output error usually occurs on the order of a few percent. Depending on the ratio of torque axial force,
Output errors may occur on the order of 10%. For this reason, it is not possible to accurately control the torque actuator and axial force actuator.
It was not possible to accurately apply alternating torque and alternating axial force.

(C) Purpose Therefore, the present invention provides a method for extracting torque detection output and axial force detection output from a torque axial force detector in a material testing machine that applies torsional load and tensile or compressive load to a test piece. Compensates for mutual interference between the torque detection output and the axial force detection output,
This was done with the aim of solving the above-mentioned conventional problems.

(D) Configuration According to the present invention, a torque actuator that applies a torsional load to a test piece, an axial force actuator that applies a tensile or compressive load to the test piece, and a torque actuator that applies a tensile or compressive load to the test piece, and a A torque axial force detector to be detected, a circuit that extracts the torque detection output and axial force detection output of the torque axial force detector, and a torque detection output that is at the same level as the torque detection output generated in the detector when only axial force is applied. an auxiliary circuit that extracts a signal from the axial force detection output of the detector and supplies it to a torque detection output extraction circuit with a polarity opposite to that of the torque detection output of the detector; A material testing machine includes an auxiliary circuit that extracts a signal at the same level as the force detection output from the torque detection output of the detector and supplies this to an axial force detection output extraction circuit with a polarity opposite to that of the axial force detection output of the detector. provided.

(E) Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In the figure, this circuit is adapted to take out the torque detection output and the axial force detection output of the torque axial force cell 1 of the material testing machine. A torque axial force cell 1 is fixed to a machine frame 2 of a material testing machine. The test piece 3 is connected to the torque axial force cell 1 and the load rod 4. Further, this material testing machine has a torque actuator 5 and an axial force actuator 6, and the axial force actuator 6 is fixed to the machine frame 2. The load rod 4 is common to the torque actuator 5 and the axial force actuator 6.
It is arranged vertically, passes through the axial force actuator 6, and extends to the torque actuator 5. The torque actuator 5 is fitted into a guide rod 7 and guided so as to be movable up and down.

Torque axial force cell 1 has a pair of strain gauges 8
It has A and 8B. The strain gauge 8A is for detecting the torque of the test piece 3, and is connected to the torque amplifier 10A of the closed loop control circuit 9A. The amplifier 10A is connected to the amplifier range switching device 11A and the amplifier 12A, and the amplifier 12A is connected to the servo valve 1 of the torque actuator 5.
Connected to 3A. Furthermore, the function generator 14 is connected to the amplifier 12A and the servo valve 13.
It is connected between A. The strain gauge 8B is for detecting the axial force of the test piece 3, and is connected to the axial force amplifier 10B of the closed loop control circuit 9B. The amplifier 10B is connected to the amplifier range switching device 11B and the amplifier 12B, and the amplifier 12B is connected to the servo valve 13 of the axial force actuator 6.
Connected to B. Then, the function generator 14 connects the amplifier 12B and the servo valve 13.
It is connected between B.

Furthermore, this circuit has a pair of auxiliary circuits 15A, 1
It has 5B. And each auxiliary circuit 15A, 15
Adjusters 16A and 16B are provided at B, respectively.
The regulators 16A and 16B are connected to the amplifier 10A of the closed loop control circuit 9A and the amplifier range switching device 1.
1A and between the amplifier 10B of the closed loop control circuit 9B and the amplifier range cutting device 11B. The operation of these auxiliary circuits 15A, 15B and their regulators 16A, 16B will be described later.

In the material testing machine configured as described above,
When hydraulic pressure is supplied to the torque actuator 5, torque can be applied to the test piece 3 by the torque actuator 5 and the load rod 4. At the same time, if hydraulic pressure is supplied to the axial force actuator 6, an axial force can be applied to the test piece 3. Therefore, the test pieces 3 can be subjected to a combined stress test. It is also possible to apply alternating torque and alternating axial force to the test piece 3.

Furthermore, when a torque is applied to the test piece 3, the strain gauge 8A of the torque axial force detection cell 1 detects the torque of the test piece 3. The torque detection output is given to the torque amplifier 10A of the closed loop control circuit 9A, passes through the amplifier range switching device 11A, and is given to the amplifier 12A. The signal is then compared with the setting signal of the function generator 14 and applied to the servo valve 13A of the torque actuator 5. Therefore, the torque actuator 5 is feedback-controlled by the closed-loop control circuit 9A and the servo valve 13A, and torque is applied to the test piece 3 in accordance with the setting signal of the function generator 14. Also,
When an axial force is applied to the test piece 3, the strain gauge 8B of the torque axial force detection cell 1
The axial force of is detected. The axial force detection output is given to the torque amplifier 10B of the closed loop control circuit 9B, passes through the amplifier range switching device 11B,
The signal is applied to amplifier 12B. The signal is then compared with the setting signal of the function generator 14 and applied to the servo valve 13B of the axial force actuator 6. Therefore, the closed loop control circuit 9B
The axial force actuator 6 is feedback-controlled by the servo valve 13B, and an axial force is applied to the test piece 3 in accordance with the setting signal of the function generator 14.

However, as described above, in the past, mutual interference occurred between the torque detection output and the axial force detection output of the torque axial force cell 1, and this affected the feedback control of the torque actuator 5 and the axial force actuator 6. . This circuit can compensate for mutual interference between the torque detection output and the axial force detection output, and can accurately control the torque actuator 5 and the axial force actuator 6. For example, when the axial force detection output of the torque axial force cell 1 is extracted by the closed loop control circuit 9B, a signal is extracted from the axial force detection output of the torque axial force cell 1 by the auxiliary circuit 15A. moreover,
The level of the signal of the auxiliary circuit 15A is adjusted by the regulator 16A. Then, a signal having the same level as the torque detection output generated in the torque axial force cell 1 when only axial force is applied to the test piece 3, that is, the torque detection output generated due to mutual interference, is extracted. The magnitude of the torque detection output generated in the torque axial force cell 1 when only axial force is applied is proportional to the axial force detection output of the torque axial force cell 1. Therefore, it is easy to extract a signal having the same level as the torque detection output from the axial force detection output of the torque axial force cell 1. This can be accomplished with regulator 16A alone. This signal is then given to the closed loop control circuit 9A with the opposite polarity to the torque detection output of the torque axial force cell 1. Therefore, the torque detection outputs caused by mutual interference are canceled out. This compensates for mutual interference, and only the torque detection output corresponding to the torque of the test piece 3 is output from the amplifier range switching device 11A.
and is applied to amplifier 12A. Therefore, the torque actuator 5 can be accurately controlled.

Similarly, when the closed loop control circuit 9A takes out the torque detection output of the torque axial force cell 1, the auxiliary circuit 15B takes out a signal from the torque detection output of the torque axial force cell 1. Further, the level of the signal from the auxiliary circuit 15B is adjusted by the regulator 16B, and a signal having the same level as the axial force detection output generated in the torque axial force cell 1 when only torque is applied to the test piece 3 is extracted. Then, the signal is given to the closed loop control circuit 9B with the opposite polarity to the axial force detection output of the torque axial force cell 1. This compensates for mutual interference and
Only the axial force detection signal corresponding to the axial force passes through the amplifier range switching device 11B and is applied to the amplifier 12B. Therefore, the axial force actuator 6 can be accurately controlled.

Therefore, when only the axial force is applied to the test piece 3 by the shaft actuator 6, the problem of alternating torque being applied to the test piece 3 as in the prior art does not occur. When only torque is applied to the test piece 3 by the torque actuator 5, no alternating axial force is applied to the test piece 3. Furthermore, when alternating torque and alternating axial force are applied to the test piece 3, mutual interference between the torque detection output and the axial force detection output is compensated, and the output error is corrected. Therefore, the torque actuator 5 and the axial force actuator 6 can be accurately controlled, and alternating torque and alternating axial force can be accurately applied.

(F) Effect As explained above, according to the present invention, torque is applied to the test piece 3 by the torque actuator 5, and a tensile or compressive load is applied to the test piece 3 by the axial force actuator 6. The torque and axial force of the test piece 3 are detected by the torque axial force detector 1, and the torque detection output and axial force detection output of the torque axial force detector 1 are extracted by the output extraction circuit. Furthermore, by the auxiliary circuit 15A,
A signal with the same level as the torque detection output generated in detector 1 when only axial force is applied is extracted from the axial force detection output of detector 1, and this signal has the opposite polarity to the torque detection output of detector 1 and is sent to the torque detection output extraction circuit. given to. Similarly, the auxiliary circuit 15B extracts a signal from the torque detection output of the detector 1 that is at the same level as the axial force detection output generated in the detector 1 when only torque is applied, and this signal is used as the axial force detection output of the detector 1. The reverse polarity is given to the axial force detection output extraction circuit. Thereby, mutual interference between the torque detection output and the axial force detection output can be compensated for, and the torque actuator 5 and the axial force actuator 6 can be accurately controlled. Therefore, test piece 3
It is possible to accurately test materials and achieve the intended purpose.

[Brief explanation of the drawing]

The drawing is a circuit diagram showing an embodiment of the present invention. 1...Torque axial force cell, 9A, 9B...Closed loop control circuit, 15A, 15B...Auxiliary circuit, 16A, 16B...Adjuster.

Claims (1)

[Claims] 1. A torque actuator that applies a torsional load to the test piece, an axial force actuator that applies a tensile or compressive load to the test piece, and a torque axial force detector that detects the torque and axial force applied to the test piece. A circuit configured to extract the torque detection output and the axial force detection output of the torque axial force detector, and a circuit configured to extract the torque detection output and the axial force detection output of the torque axial force detector, and a signal having the same level as the torque detection output generated in the detector when only axial force is applied to the axial force of the detector. an auxiliary circuit that extracts the detection output and supplies it to a torque detection output extraction circuit with a polarity opposite to that of the torque detection output of the detector, and a signal that is at the same level as the axial force detection output generated in the detector when only torque is applied A material testing machine comprising an auxiliary circuit that extracts the torque detection output of the detector and supplies it to an axial force detection output receiving circuit with a polarity opposite to that of the axial force detection output of the detector.