JPH0230754Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a test load measuring device for a high-pressure material testing machine.

Material tests can be performed under high pressure by placing a test piece inside a high-pressure container and applying a test load to it.

To apply a test load to a test piece, a load rod such as a push-pull rod is axially displaceably protruded into the high-pressure vessel. Then, one end of the test piece placed inside the high-pressure container may be attached to the inner end of the load rod. Further, in this type of material testing machine, a load cell is generally used to detect the load applied to the test piece. Although it is possible to detect the load on the test piece by installing this load cell on the load rod, in this case, when performing a fatigue test on the test piece, it is necessary to vibrate the load cell together with the load rod, and the influence of the inertial force Therefore, there is a problem that the measurement accuracy of the load cell decreases. To avoid this, a measuring rod is axially displaceably protruded into the high-pressure vessel from the opposite side of the load rod, and the other end of the test piece is attached to the inner end of the measuring rod. Then, the load cell installed on this measuring rod may be fixed to the main body of the testing machine. The test load is transmitted to the load cell by the measuring rod and then to the main body of the testing machine. Therefore, the test load can be detected by the load cell. Since the load cell is fixed to the main body of the testing machine, even if the load rod vibrates, the load cell itself does not vibrate and its measurement accuracy does not deteriorate. however,
When the measuring rod is projected into the interior of the high pressure vessel, the internal pressure of the high pressure vessel acts on the inner end of the measuring rod. This affected the load cell, causing an error in the measured value of the test load. Since the internal pressure of a high-pressure container fluctuates, it is difficult to accurately correct errors in measurement values. Therefore, it was inevitable that the measurement accuracy would decrease.

This invention was made with the aim of eliminating the above-mentioned conventional drawbacks and increasing measurement accuracy in this type of test.

In this device, a load rod that applies a test load to a test piece is protruded into a high-pressure container so that it can be displaced in the axial direction, and one end of the test piece placed inside this high-pressure container is attached to the inner end of the high-pressure rod. In the lower material testing machine, a measuring rod is axially displaceably protruded into the high pressure vessel from the opposite side of the load rod, and the other end of the test piece is attached to the inner end of the measuring rod. At the same time, a load cell equipped on the measuring rod is fixed to the main body of the testing machine, and a cylinder is provided to house the outer end of the measuring rod so as to be displaceable in the axial direction, and an internal pressure of the high pressure container is applied to the cylinder. The internal pressure of the high pressure container acting on the inner end of the measuring rod is offset by the internal pressure of the cylinder acting on the outer end of the measuring rod. This is characterized by eliminating the influence of the internal pressure of the high-pressure container.

Embodiments of this invention will be described below with reference to the drawings.

In the figure, a test piece 1 is a sealed high-pressure container 2
is located inside. The high-pressure container 2 consists of a main body 3 and a lid plate 4. The main body 3 and the cover plate 4 are connected by bolts 5, and the gap between them is sealed by a sealing edge 6 of the main body 3.

A test load is applied to the test piece 1 by a push-pull rod 7. The push-pull rod 7 protrudes from the bottom surface of the main body 3 into the interior of the high-pressure vessel 2 so as to be able to be displaced in the axial direction. The space between the push pull rod 7 and the main body 3 is sealed by a high-performance gasket 8.

The measuring rod 9 connects the lid plate 4 to the high pressure container 2.
It protrudes into the inside of the shaft so that it can be displaced in the axial direction. The space between the measuring rod 9 and the cover plate 4 is similarly sealed by a high-performance packing 8. Both ends of the test piece 1 are attached to the inner ends of a push-pull rod 7 and a measuring rod 9 by means of fixtures 10, respectively.

The measuring rod 9 is connected to a load cell 11. As the load cell 11, for example, a flat shear type is used which converts the load transmitted by the measuring rod 9 into shear force and measures this electrically.

The outer end of the measuring rod 9 is accommodated in a cylinder 12 so as to be axially displaceable. The gap between the measuring rod 9 and the cylinder 12 is also sealed by a high-performance packing 8. The cylinder 12 and load cell 11 are attached to the cover plate 4 with bolts 13. In this embodiment, a flow path 14 is formed inside the measuring rod 9 for guiding the internal pressure of the high pressure container 2 to the cylinder 12.

In the high-pressure material testing machine configured as described above, when the push-pull rod 7 is reciprocated in the axial direction, that is, in the vertical direction, by a suitable drive mechanism, a tensile and compressive cyclic load is applied to the test piece 1. . Since the measuring rod 9 protrudes into the high-pressure vessel 2 so as to be displaceable in the axial direction, that is, in the vertical direction, the tensile repetitive load applied to the test piece 1 is transmitted to the load cell 11 by the measuring rod 9. The load cell 11 electrically measures the repeated tension/compression load. The reaction force of the load cell 11 is supported by the cover plate 4.

At this time, the internal pressure of the high-pressure container 2 acts on the inner end of the measuring rod 9, and an upward force is applied to the measuring rod 9. Measuring rod 9
When the outer diameter of the inner end of the rod is d ₁ and the internal pressure of the high-pressure vessel 2 is P, the upward force F ₁ applied to the measuring rod 9 is expressed by the formula F ₁ =P×πd ₁ ² /4. It can be done.

At the same time, the internal pressure of the high-pressure vessel 2 is led to the cylinder 12 by the channel 14 of the measuring rod 9. Therefore, the internal pressure of the cylinder 12 acts on the outer end of the measuring rod 9, and a downward force is applied to the measuring rod 9. The internal pressure of the cylinder 12 is the same as the internal pressure of the high pressure vessel 2. If the outer diameter of the outer end of the measuring rod 9 is d ₂ , the downward force applied to the measuring rod 9 is expressed by the formula F ₂ =P×πd ₂ ² /4.

Here, if the diameters d ₁ and d ₂ of the inner and outer ends of the measuring rod 9 are the same, then P×πd ₁ ² /4=P×πd ₂ ² /4 Therefore, F ₁ =F ₂ Therefore, the upward force F ₁ and the downward force F ₂ can be made the same. Even if the internal pressure P of the high-pressure container 2 fluctuates, the upward force F ₁ and the downward force F ₂ are kept the same regardless of this. Therefore, the upward force F ₁ and the downward force F ₂ applied to the measuring rod 9 are always balanced and are not transmitted to the load cell 11. In other words, the influence of the internal pressure of the high-pressure container 2 acting on the inner end of the measuring rod 9 on the load cell 11 can be offset by the internal pressure of the cylinder 12 acting on the outer end of the measuring rod 9. It is something. Therefore, no error occurs in the measured value of the test load, and measurement accuracy can be improved.

In the above embodiment, the push-pull rod 7 is projected from below and the measuring rod 9 is projected from above into the high-pressure vessel 2, but on the contrary, the push-pull rod 7 is projected from above. Alternatively, the measuring rod 9 may protrude from below. Furthermore, the measuring rod 9 may protrude from the main body 3 of the high-pressure vessel 2 instead of from the cover plate 4. When the inside of the high-pressure container 2 is heated to a high temperature, it can be used as is as a so-called autoclave system.

As explained above, this invention is based on the high pressure vessel 2.
One end of the test piece 1 placed inside the load rod 7
The measuring rod 9 is attached to the inner end of the measuring rod 9, and the measuring rod 9 protrudes from the opposite side of the load rod 7 into the high pressure vessel 2 so as to be displaceable in the axial direction, and the other end of the test piece 1 is attached to the inner end of the measuring rod 9. Install. Since the load cell 11 equipped on the measuring rod 9 is fixed to the main body of the testing machine, for example, the lid plate 4 of the high pressure vessel 2, the test load is transmitted to the load cell 11 by the measuring rod 9, and the load cell 11
can be transmitted to the main body 4 of the testing machine via. The body 4 receives and supports the transmitted test load. Therefore, the test load can be detected by the load cell 11. Load cell 1
1 is installed not in the load rod 7 but in the measuring rod 9, and is fixed to the main body 4 of the testing machine. Therefore, when performing a fatigue test on the test piece 1 by applying repeated loads to the test piece 1, for example, the load rod Even if 7 vibrates, the load cell 11 itself does not vibrate and is not affected by it. Therefore, the measurement accuracy of the load cell 11 does not decrease. Furthermore, in this invention, the outer end of the measuring rod 9 is accommodated in the cylinder 12 so as to be displaceable in the axial direction, and the internal pressure of the high-pressure vessel 2 is guided to the cylinder 12 through a suitable flow path 14, so that the measuring rod 9 can be moved easily in the cylinder 12. The internal pressure of the high-pressure vessel 2 acting on the inner end of the rod 9 can be offset by the internal pressure of the cylinder 12 acting on the outer end of the measuring rod 9. Therefore, the load cell 11 is not affected by the internal pressure of the high pressure container 2. As a result, the test load can be measured accurately and the measurement accuracy can be improved.

[Brief explanation of the drawing]

The drawing is a sectional view showing one embodiment of this invention. DESCRIPTION OF SYMBOLS 1... Test piece, 2... High pressure container, 9... Measuring rod, 11... Load cell, 12... Cylinder, 14... Channel.

Claims (1)

[Scope of utility model registration request] A high-pressure material test in which a load rod that applies a test load to a test piece is protruded into a high-pressure container so that it can be displaced in the axial direction, and one end of the test piece placed inside the high-pressure container is attached to the inner end of the load rod. In the machine, a measuring rod is axially displaceably protruded into the high pressure vessel from the opposite side of the load rod, the other end of the test piece is attached to the inner end of the measuring rod, and the A load cell equipped on the measuring rod is fixed to the main body of the testing machine, and a cylinder is provided to accommodate the outer end of the measuring rod so as to be displaceable in the axial direction, and a cylinder for guiding the internal pressure of the high pressure container to the cylinder. a flow path is provided, and the internal pressure of the high-pressure container acting on the inner end of the measuring rod is offset by the internal pressure of the cylinder acting on the outer end of the measuring rod, and the high-pressure container with respect to the load cell is A test load measuring device characterized in that the influence of internal pressure is removed.