JPS588463B2 - Deformation measurement device under high pressure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a measuring device for measuring the amount of displacement between test piece gauges in a pressure vessel.

Conventionally, stress corrosion test chambers under high-temperature heating have been known (for example, Utility Model Publication No. 1973-008958),
When using this test chamber or applying stress to the test piece in some way within a pressure vessel, it was extremely difficult to measure the amount of displacement between the test piece gauges due to the high temperature and pressure.

In addition, in other conventional measuring instruments, the movement of the pull rod is converted into the movement of the test piece, so the strain due to heat, tension, compression, shearing, bending, etc. of the chuck of the test piece and the pull rod is also synthesized. Because of the detected value, accurate elongation measurements were not possible.

SUMMARY OF THE INVENTION An object of the present invention is to provide an elongation measuring instrument that can obtain accurate data for measuring the amount of deformation between specimen gauges under high temperature and/or high pressure.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

The figure shows an embodiment of a measuring device according to the present invention, and the measuring device in this figure detects the elongation of a test piece when tensile stress is applied.

By deforming the structure that applies force to the test piece, a person concerned can easily create a structure that detects the amount of deformation when compressive stress, shear stress, bending force, etc. are applied.

The test piece 12 is supported by a known support device in a pressure vessel 9 consisting of a pressure vessel main body 9a and a pressure vessel lid 9b, and is sealed by a pressure vessel lid plate 9b.

A shoulder 1 and a shoulder 2 are attached to the test piece gauges a and b, and the detection end 3a of the detection tube 3 is attached to the shoulder 1.
The end 4a of the detection rod 4 contacts the shoulder 2.The detection tube 3 is slidably provided inside the extensometer pressure vessel 5,
The detection rod 4 is slidably provided inside the extensometer pressure vessel 5 and inside the detection tube 3.

The lower end of the test specimen 12 is fixed to the lid 9b via the load column 10, and the tensile force W is applied to the upper end by a pull rod 8 passing through the pull rod guide 6 and sealing nut 7.

The extensometer pressure vessel 5 consists of a main body 5a that is attached to a pressure vessel lid 9b and has an inner hole 5b in the center thereof, and a lid part 5h, and the inner hole 5b slidably receives the detection tube main body part 3b. .

An inner hole 5c with a larger diameter is provided at the upper part of the inner hole 5b, and an inner hole 5b with an even larger diameter is provided at the upper part.

The upper large diameter portion 3h of the detection tube 3 passes through the inner hole 5c, and the upper flange 31 of the detection tube 3 is located in the inner hole 5d.

The flange portion 31 is biased downward by a spring 3g installed between it and the lower part of the extensometer pressure vessel lid 5h, thereby causing the detection end 3a provided at the lower end of the detection tube 3 to be biased toward the shoulder 1. Ensure contact.

A differential transformer holder rod 3c is fixedly attached to the flange portion 31, and the rod extends upwardly through the lid 5h to adjust the differential transformer through the differential transformer holder 3d and the differential transformer adjustment nut. It is connected to the dynamic transformer 3f.

The penetrating portion is sealed with an O-ring or the like.

On the other hand, the detection rod 4 extends upward inside the detection tube and is biased downward by a spring 4d through a spring receiver 4c in the inner hole 5d, so that the detector 4a provided at the lower end of the detection rod is securely attached to the shoulder 2. bring into contact.

The detection rod extends further upward into the inner hole 5j in the protrusion 51 provided at the center of the lid 5h, and the core 4b is fixed to the upper end thereof.

The core 4b is located at a position corresponding to the transformer 3f, and is known in the art.
A change in the relative position of the core 4b and the transformer 3f is electrically detected by the method.

As is clear from the drawing, the inside of the detection tube 3, the lower part of the inner hole 5b, the upper part of 5c, and the insides of 5d and 5j are pressure vessels 9.
These interiors are kept at the same pressure as the interior of the pressure vessel 9.

Therefore, the detection rods 4 and 4b as a whole exist within the high pressure section, and the resultant force of pressure forces is O, so that they are not affected by pressure.

On the other hand, for the detection tube 3, the differential transformer holder rod 3
Since c extends through the pressure section to the transformer 3f in the atmospheric section, the resultant force due to the pressure is not zero, but receives a force pushing upward in the drawing.

In order to cancel this force, in the illustrated device, the extensometer pressure vessel main body 5a is provided with a hole 3j that communicates a part of the inner hole 5c with the atmosphere, and the atmospheric pressure is detected at the portion where the diameter of the detection tube 3 changes, that is, the portion 3h. In order for the resultant force of the pressure acting on the lower step to be 0, is there an upward force? It is necessary to make the downward force equal, which means that the cross-sectional area of each part is (S2-S)'
This is satisfied by setting XP=(S3-s, -S,)xP.

Here S1: Cross-sectional area of the inner diameter of the detection tube.

S2: Cross-sectional area of the outer diameter part of the detection tube.

S3: Cross-sectional area of the outer diameter part of the large diameter part (3h) at the top of the detection tube.

S4: Total cross-sectional area of the penetrating portion of the differential transformer holder rod.

P: Pressure inside the pressure vessel That is, it may be set to S4-83-82.

As a result, neither the detection rod 4 nor the detection tube 3 is affected by pressure, and it is ensured that the detection ends 3a and 4a are always in constant contact with the shoulders 1 and 2.

In this way, the amount of displacement between gauge points on the test piece can be accurately converted into relative displacement between the differential transformer and the core, and the effects of deformation of the pull rod and threaded portion of the test piece can be ignored regardless of the pressure value. Accurate displacement measurement between gauge points a and b can be performed without any interference.

Note that a suitable seal, such as an O-ring, is provided between the detection tube 3 and the vessel 5 to prevent communication between the inside of the pressure vessel and the atmosphere through the hole 3j.

Further, the outer diameter portion of the differential transformer holder 3d integrated with the differential transformer holder rod 3c is threaded, and the position of the core 4b and the differential transformer 3f can be adjusted using a differential transformer adjusting nut 3e.

Furthermore, when elongation is measured by keeping the pressure vessel at a high temperature in a heating furnace 11 having a heater 13 or the like, a cooling chamber 14 may be provided at the bottom of the extensometer pressure vessel 5 to prevent and protect the O-ring from heating. good.

In the present invention, the elongation amount is measured when a tensile force W is applied to the sample, but instead of the tensile force, compression, shearing,
The present invention is similarly applicable to cases such as bending.

[Brief explanation of the drawing]

The attached figure shows a cross-sectional view of an embodiment of the measuring device according to the invention. Explanation of symbols of main parts, Pressure vessel...9, Deformation measurement pressure vessel...5, Magnetic core...
4b, Detection rod...4, Detection tube...3,
Transformer...3f, Support member...3c
o

Claims (1)

[Claims] 1. A pressure vessel for receiving a test piece: A pressure vessel for measuring deformation communicating with the pressure vessel; movable in response to displacement of one point of the test piece, and having a magnetic core at the top. and a detection rod entirely disposed within the test piece pressure vessel and the deformation measurement pressure vessel; at least a portion of the detection rod is enclosed;
a detection tube movable in response to the displacement of other gauge points of the test piece; a transformer provided in the atmosphere near the magnetic core; one end attached to the transformer, and a pressure vessel for measuring the amount of displacement. and a support member having the other end attached to the detection tube, and in order to eliminate pressure imbalance on the detection tube caused by the penetration of the support member, a portion of the detection tube is exposed to the atmosphere. A deformation measurement device under high pressure that is in contact with the 2. In the measuring instrument according to claim 1, the detection tube has a portion having a diameter that is a dog at the top thereof, the portion where the diameter changes is made to be in contact with the atmosphere, and the portion through which the support member penetrates. A deformation measurement device under high pressure in which the sum of the cross-sectional areas of is equal to the difference between the area of the large diameter portion and the cross-sectional area of the outer diameter portion of the detection tube.