JPH068781B2 - Displacement measuring device for test piece of material testing machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a material testing machine for testing a material of a test piece, and particularly to a test piece displacement amount measurement for measuring a displacement amount of the test piece. It relates to the device.

(B) Conventional technology For example, in order to perform a material test on a test piece under high temperature and high pressure, the test piece (T.
P.) must be accommodated. Then, while applying a load to the test piece (TP), measure the displacement amount of the test piece (TP),
It is necessary to material test the test piece (TP) inside the high temperature and high pressure vessel (1). In the case of the tensile test, it is usually required to generate a displacement between the gauge marks of the test piece (TP) and measure the displacement amount between the gauge marks.

For this reason, conventionally, a pair of protrusions (2) were provided on the outer periphery of the test piece (TP) at an interval corresponding to the gauge length of the test piece (TP). Then, the pair of arms (3) is fitted into the protrusion (2) and fixed to the test piece (TP). Further, the detection rod (4) and the detection tube (5) were engaged with each arm (3). Therefore, when displacement occurs between the reference points of the test piece (TP), each arm (3) is displaced integrally with the test piece (TP). The detection rod (4) and the detection tube (5) follow the test piece and the arm (2) and are relatively displaced. By this, the displacement amount of the test piece (TP) is taken out. Therefore, when the displacement amount of the detection rod (4) and the detection tube (5) is detected outside the high temperature and high pressure container (1), the displacement amount of the test piece (TP) can be measured.

However, in this test piece displacement amount measuring device, each arm (3) is integrally displaced with the test piece (TP) so that the detection rod (4) and the detection tube (5) follow each arm (3). Requires that each arm (3) be firmly fixed to the test piece (TP). For this reason, it was necessary to make the protrusion (2) of the test piece (TP) large. Increasing the protrusion (2) allows each arm (3)
Although it can be firmly fixed to the test piece (TP),
It is unavoidable that (2) affects the displacement of the test piece (TP). For this reason, there is a problem that the amount of displacement between gauge marks cannot be accurately measured.

(C) Purpose Therefore, the present invention is a material testing machine for material testing a test piece inside a sealed container such as a high temperature and high pressure container, and it is not necessary to increase the projection of the test piece, and the displacement of the test piece can be accurately measured. It is intended to be measured.

(D) Structure According to the present invention, the test piece is housed inside the sealed container,
While applying a load to the test piece, the displacement amount of the test piece is measured, and in the material testing machine configured to test the material of the test piece inside the sealed container, a pair of arms inside the sealed container. One end is engaged with the test piece, an arm connecting member is provided between both ends of each arm, the arms are connected to each other by the connecting member, and the outer surface of the hermetic container is communicated with the inside of the hermetic container. A chamber is provided so as to project, the wall surface of the chamber is formed in a direction parallel to the load direction of the test piece, and a pair of magnetic bodies are housed inside the chamber, and each magnetic body is connected to the other end of each arm. , A pair of detection units for detecting the position of each magnetic body is provided outside the chamber, and each detection unit is opposed to each magnetic body via a wall surface of the chamber,
When the displacement of the test piece occurs, the arms are relatively swung with the connecting member as a fulcrum, and the swing amounts of the arms are detected by the detection units. A displacement measuring device is provided.

(E) Example An example of the present invention will be described below. FIG. 1 shows an embodiment of the present invention. The test piece (TP) is housed inside the high-temperature high-pressure container (6) and arranged vertically. High temperature and high pressure container
(6) is inserted inside the heating furnace (7). This tester is designed to perform a tensile test on a test piece (TP) inside a high temperature and high pressure container (6), and the test piece (TP) is chucked by a pair of upper and lower pull rods (not shown). Therefore, a tensile load can be applied to the test piece (TP) by the pull rod to cause a displacement between the gauge points of the test piece (TP).

This test piece has a pair of upper and lower arms (8H) and (8L), and the arms (8H) and (8L) are arranged horizontally and in parallel on the right side of the test piece (TP). The test piece (TP) consists of a pair of upper and lower protrusions (9
H) and (9L), and the protrusions (9H) and (9L) are provided on the outer periphery of the test piece (TP) at intervals corresponding to the gauge length of the test piece (TP). Then, inside the high-temperature high-pressure container (6), one end of each arm (8H), (8L) is fitted into the projections (9H), (9L) and engaged with the test piece (TP). Further, an elongated arm accommodating sleeve (10) is formed as a part of the high temperature and high pressure container (6),
The sleeve (10) penetrates the wall of the heating furnace (7), and the arm (8H),
(8L) is housed inside this sleeve (10). Further, a leaf spring (11) is provided between both ends of the arms (8H) and (8L), and the arms (8H) and (8L) are connected to each other by the leaf spring (11). The upper arm (8H) is connected to the inner surface of the sleeve (10) by the coil spring (12). The coil spring (12) is for supporting the own weight of each arm (8H), (8L), and is provided at the same position as the leaf spring (11).

In addition, this tester has a pair of upper and lower differential transformers (13H), (13H).
L). The differential transformers (13H) and (13L) are composed of a coil (14) and a core (15). Therefore, in this embodiment, the cores (15) of the differential transformers (13H) and (13L) are used as the pair of magnetic bodies, and the differential transformers (13H) and (13L) are used as the pair of detection units.
L) coil (14) is used and coil (1
4) is provided outside the high temperature and high pressure container (6) and is arranged above and below the arm housing sleeve (10). Also,
A water cooling jacket (16) is provided on the outer circumference of the arm housing sleeve (10), and the coil (14) is attached to the outer surface of the water cooling jacket (16) and is connected to a computing device (17). further,
Pipe-shaped chambers (18) are provided above and below the arm housing sleeve (10), and each differential transformer (13H), (13L)
The core (15) of each is housed inside each chamber (18)
(14) are arranged around each chamber (18). The chamber (18) is a part of the high temperature and high pressure vessel (6) and communicates with the inside of the high temperature and high pressure vessel (6) and the arm housing sleeve (10).
The core (15) is connected to the other ends of the arms (8H) and (8L). Therefore, the coil (14) of each differential transformer (13H), (13L) is connected to the core (15) of each arm (8H), (8L) via the peripheral surface of the chamber (18), that is, the wall surface of the high temperature and high pressure container. It is the one facing.

In the test piece displacement amount measuring device configured as described above, when displacement occurs between the reference points of the test piece (TP), each arm
(8H) and (8L) follow the protrusions (9H) and (9L) of the test piece (TP).
Then, the arms (8H) and (8L) relatively swing about the leaf spring 11 as a fulcrum. By this, the displacement amount of the test piece (TP) is taken out. Further, the cores (15) of the differential transformers (13H) and (13L) follow the arms (8H) and (8L) and are displaced relative to the coil (14). Therefore, each differential transformer (13
H) and (13L) detect the swing amount of each arm (8H) and (8L). The detection output is sent to the arithmetic unit (17), and the arithmetic unit
(17) adds the detection outputs of the differential transformers (13H) and (13L). By this, the amount of displacement of the test piece (TP) is measured.

Therefore, unlike the above-mentioned conventional device, this device has an arm (8
It is not necessary to firmly fix H) and (8L) to the test piece (TP).
Each arm (8H), (8L) follows the projections (9H), (9L) of the test piece (TP) and can be relatively swung, and each arm (8H), (8L) can be lightly moved. It suffices to fit one end of each into the protrusions (9H) and (9L). Therefore, it is not necessary to increase the protrusions (9H) and (9L) of the test piece (TP). The protrusions (9H) and (9L) can be made small, and the protrusions (9H) and (9L) hardly affect the displacement of the test piece (TP). Therefore, the amount of displacement between the gauge marks can be accurately measured.

Further, the arms (8H) and (8L) act as levers for enlarging or reducing the displacement amount of the test piece (TP). The lever ratio can be arbitrarily selected depending on the position of the fulcrum of the arms (8H) and (8L), that is, the position of the leaf spring (11). Also, the core (15) of the differential transformer (13H), (13L)
Since there is only a single wall surface of the chamber (18) between the coil and the coil (14), the differential transformers (13H) and (13L) have high sensitivity. Therefore, the swing amount of the arms (8H) and (8L) can be accurately detected. Further, most of the arms (8H) and (8L) are housed in the arm housing sleeve (10), not in the main body of the high temperature and high pressure container (6). Therefore, the main body of the high temperature and high pressure container (6) does not need to be large and can be made compact.

Various modifications of the present invention are possible. For example, not only on the right side of the test piece (TP), but also on the left side
If similar mechanisms such as (8H), (8L) and differential transformers (13H), (13L) are provided, the displacement between gauge points can be measured on the left side of the test piece (TP). Therefore, it is possible to obtain the average value of the displacement amount between the reference points.

Also, instead of the leaf spring (11), such as a pin or pivot,
Other connecting members may be used to connect the arms (8H) and (8L) to each other by the connecting member. Furthermore, the arms (8H) and (8L) do not necessarily have to be arranged in parallel.
Depending on the case, the arms (8H) and (8L) may be crossed. In Fig. 2, a pair of arms (8H) and (8L) are crossed with each other, and each arm (8H), (8
L) is connected to each other. When displacement occurs between the gauge points of the test piece (TP), each arm (8H), (8L) relatively swings around the pin or pivot (19) as a fulcrum, and the differential transformer
The swing amount of each arm (8H), (8L) is detected by (13H), (13L). Therefore, the amount of displacement of the test piece (TP) can be similarly measured.

Further, it is not always necessary to provide the protrusions (9H) and (9L) on the outer periphery of the test piece (TP). For example, arm (8H), (8L) and test piece
(TP) may be provided with a pin on one side and a pin hole on the other side, and the pin may be inserted into the pin hole. The ends of the arms (8H) and (8L) may be pressed against the test piece (TP) by a coil spring. In short, the arms (8H) and (8L) should swing so that each arm (8H) and (8L) swings when displacement occurs between the gauge marks of the test piece (TP).
It suffices to engage one end of the test piece (TP).
In addition, a test piece (TP) is provided by one end of each arm (8H), (8L).
By sandwiching in the diametrical direction, the amount of displacement in the diametrical direction can be measured. Further, the apparatus can be used for material tests other than the tensile test, for example, bending test or shear test, and the displacement of the test piece can be measured.

This device can also measure the displacement of a test piece inside a sealed container other than the high temperature and high pressure container, for example, a vacuum chamber.

(F) Effect As described above, according to the present invention, the sealed container (6)
Inside of, a pair of arms (8H), one end of (8L) engages the test piece (TP), each arm (8H), (8L) is provided with an arm connecting member (11) between both ends, The arms (8H) and (8L) are connected to each other by the connecting member (11). Furthermore, a sealed container
Chamber (18) communicating with the inside of the sealed container (6) on the outer surface of (6)
, The wall of the chamber (18) is formed in a direction parallel to the load direction of the test piece (TP), a pair of magnetic bodies (15) are housed inside the chamber (18), and each magnetic body ( 15) each arm (8
H) and (8L) are connected to the other end. Furthermore, a pair of detection units (14) for detecting the position of each magnetic body (15) is provided outside the chamber (18), and each detection unit (14) is provided via the wall surface of the chamber (18).
Face each magnetic body (15). Therefore, the test piece (TP)
When the displacement occurs, each arm (8H), (8L) swings relative to the connecting member (11) as a fulcrum, and each detection unit (14) swings each arm (8H), (8L). The momentum is detected. This makes it possible to measure the amount of displacement of the test piece (TP).

Therefore, according to the present invention, even with the test piece (TP) inside the sealed container (6), the displacement amount of the test piece (TP) can be measured by the external detection unit (14). Moreover,
It is not necessary to firmly fix the arms (8H) and (8L) to the test piece (TP). Each arm (8H), (8L) with the connecting member (11) as a fulcrum
It is only necessary to make each arm swing relatively, and each arm (8
It is only necessary to engage one end of H) and (8L) with the test piece (TP). Therefore, it is not necessary to provide the test piece (TP) with a large protrusion. Small protrusions (9H) and (9L) should be provided.
(9H) and (9L) hardly affect the displacement of the test piece (TP). Therefore, the amount of displacement between the gauge marks can be accurately measured.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is an explanatory view showing a modification of FIG. 1, and FIG. 3 is an explanatory view showing a conventional test piece displacement amount measuring device. (TP) …… Test piece (6) …… High temperature and pressure vessel (8H), (8L) …… Arm (11) …… Flat spring (13H), (13L) …… Differential transformer

Claims (1)

[Claims] 1. A test piece is housed in a sealed container, a load is applied to the test piece, a displacement amount of the test piece is measured, and a material test of the test piece is performed inside the sealed container. In the material testing machine described above, one end of a pair of arms is engaged with the test piece inside the sealed container, arm connecting members are provided between both ends of each arm, and the arms are connected to each other by the connecting member. Further, a chamber that communicates with the inside of the hermetic container is provided on the outer surface of the hermetic container, and a wall surface of the chamber is formed in a direction parallel to the load direction of the test piece, and a pair of magnetic members is provided inside the chamber. A body is housed, each of the magnetic bodies is connected to the other end of each of the arms, and a pair of detection units for detecting the position of each of the magnetic bodies is provided outside the chamber. detection So as to face the respective magnetic bodies, and when the displacement of the test piece occurs, the respective arms are relatively swung with the connecting member as a fulcrum, and the swing amounts of the respective arms are detected by the respective detection units. A test piece displacement amount measuring device characterized in that