JP3202545U - Internal pressure loading mechanism on tubular specimen - Google Patents

Abstract

In order to obtain the internal pressure strength characteristics of a tubular test piece having radioactivity from a remote test in a cell, the test piece is constructed by a small and simple mechanism and can be assembled and operated easily in a narrow space. Provided is an internal pressure loading mechanism for a tubular test piece that enables a high-pressure internal pressure load that enables testing and does not require a length restriction of the tubular test piece. SOLUTION: Inside a tubular test piece 1, an O-ring 4 is inserted and arranged at both ends of the tubular spacer 5 and two end plugs 2 having a screw structure and an end plug 2 having a pressure medium introduction hole. A mechanism for compressing the O-ring 4 and occluding the gap between the inner wall of the tube and the end plug by mechanically connecting the end plug of the tube with a screw structure. An internal pressure load mechanism is configured. [Selection] Figure 1

Description

  In the present invention, a tubular test piece is produced from a radioactive cladding tube used in a nuclear reactor, and the tube is formed by a high-pressure internal pressure loading method in a narrow space having a radiation shielding function called a cell. The present invention relates to an internal pressure loading mechanism to a tubular test piece when measuring the strength characteristics of the tube.

  In the case of fuel cladding tubes for reactors made of zirconium alloy, the tensile force in the circumferential direction (circumferential tensile stress) generated in the tube during use is dominant, and the deformation characteristics Because of its strong anisotropy, the pipe strength and deformation characteristics data when directly loaded only in the pipe circumferential direction are not used in the longitudinal direction uniaxial tensile test of the fuel cladding tube or the internal pressure burst test with both ends closed. It was important.

  In addition, as the data acquisition method is work in a narrow cell, the test apparatus is small and can be loaded with high reliability up to high pressure, and it is easy to operate for remote testing in the cell. Is required.

  Therefore, as shown in Patent Document 1 in the prior art, there is an open-end type internal pressure load test method in which only a uniaxial stress in the circumferential direction is generated without generating a tensile force in the longitudinal direction on the cladding tube.

  Further, as an internal pressure sealing technique for an end portion of a pipe, there is a technique for pressing a plastic sealing material against a pipe inner wall with a screw type as shown in Patent Document 2.

  Further, Patent Document 3 discloses a technique in which a sealing material is sandwiched between both ends of a tubular test piece and a sealing flange is compressed and sealed onto a test target tube, and the end of the test tube material is flared (expanded). A technique for mechanically sandwiching the inner pressure together with a sealing material to seal the internal pressure is disclosed in Patent Document 4, and other techniques for sealing the internal pressure using various shapes of O-rings are disclosed in Patent Document 5 and Patent Document 6.

  In the prior art of Patent Document 1, which is an open-end type internal pressure load test method, an O-ring (10) inserted inside a test piece (1) is connected to a tubular spacer (13) and both end plugs (11) (12). Since the structure (14) for applying a compressive force that balances with the internal pressure is essential, the testing machine is increased in size. In addition, since the structure supports the end plug, the length of the test piece is limited. Further, because the space around the test piece is limited due to the structure, there is a problem that it is difficult to incorporate a heating member and a measurement part.

  In the technique of Patent Document 2, a plastic sealing material (20) is arranged inside the test piece (1), and the sealing material is mechanically tightened between the end plug (21) and the seal compression tube (22). Since the internal pressure is sealed by the frictional force generated between the inner surface of the test piece and the internal pressure higher than the frictional force, sealing becomes impossible and there is a problem in terms of reliability.

  In patent document 3, since the test piece was compressed from both ends, there was a problem that compressive stress was generated in the test piece and the apparatus was large.

  In the technique of Patent Document 4, it is necessary to plastically deform the end of the test piece, which cannot be applied to a material with poor elongation, and has a problem that it is a large-sized apparatus and the procedure is complicated.

  In addition, in Patent Documents 5 and 6, a technique using an O-ring is disclosed, but it cannot be applied to the technical problem.

JP 2007-256164 A Japanese Utility Model Publication No. 56-043041 Japanese Patent Laid-Open No. 55-035282 JP 59-208434 A Japanese Patent No. 2636195 Japanese Patent No. 2630634

  In view of the above-mentioned deficiencies in the prior art, the present invention is composed of a small and simple structure, which makes it easy to assemble test pieces, enables test operations in a narrow space, and is a test tube. Is intended to provide an internal pressure load mechanism that can load a high internal pressure without a length limitation.

  As a means for achieving the above object, a tubular spacer and an O-ring are inserted and arranged at both ends of the tubular test piece, and the end plug for sealing and the end plug with an internal pressure introducing hole are used together. An internal pressure load mechanism that enables high internal pressure sealing is provided by compressing an O-ring with a screw mechanism provided on the end plug to close the gap between the tube inner wall and the end plug.

  As is clear from the above description, the effects listed below can be obtained according to the present invention.

  (1) A tubular spacer and an O-ring are inserted and arranged at both ends of the tubular test piece, and the O-ring is provided on the end plug with two end plugs: a sealing end plug and an end plug with an internal pressure introducing hole. It is a mechanism with high internal pressure sealability by closing the gap between the inner wall of the tube and the end plug by compressing with the screw mechanism, and in the present invention, the both end plugs are mechanically coupled with the screw mechanism. There is no need for an external end plug compression mechanism, and there is an effect that it is small and has excellent operability.

  (2) A tubular spacer and an O-ring are inserted and arranged at both ends of the tubular test piece, and the O-ring is provided on the end plug with two end plugs: a sealing end plug and an end plug with an internal pressure introducing hole. By compressing with a screw mechanism, the gap between the inner wall of the tube and the end plug is closed, thereby providing a high internal pressure sealing property, and no end plug compression mechanism from the outside is required, and the entire test piece is rod-shaped. Because of this feature, the high-temperature test does not require the production of a dedicated electric furnace and has the effect that the test can be performed by inserting it into an existing small-diameter electric furnace.

  (3) In the present invention described in the above (2), the assembled test piece is in the shape of a small bar, and since there is no structure that absorbs heat, it is possible to perform a test at a uniform test piece temperature. There is a great effect.

  (4) A tubular spacer and an O-ring are inserted and arranged at both ends of the spacer inside the tubular test piece, and the O-ring is provided at the end plug with two end plugs: a sealing end plug and an end plug with an internal pressure introducing hole. This is a mechanism with high internal pressure sealing performance by closing the gap between the inner wall of the tube and the end plug by compressing with a screw mechanism. In the present invention, the end plug and screw mechanism are housed inside the tubular test piece. Since all the structures having a means for enabling loading are accommodated in the test tube, there is an excellent effect that the length of the tubular test piece is not limited.

It is a longitudinal cross-sectional view of the internal pressure load mechanism comprised from the tubular test piece which concerns on one Embodiment of this invention, O-ring, a tubular spacer, and an end plug with a screw structure. It is a longitudinal cross-sectional view of the internal pressure loading mechanism comprised from the structure which loads a tubular test piece, an O-ring, a tubular spacer, an end plug, and an end plug restraint force in a prior art. It is a longitudinal cross-sectional view of the load mechanism which shows the end plug with a test piece, the plastic sealing material inserted in the pipe | tube inside, and a sealing material clamping | tightening function in a prior art.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same reference numerals are assigned to the same components.

  FIG. 1 is a cross-sectional view of an embodiment of the present invention, in which a tubular spacer 5 is disposed inside a tubular test piece 1 and two O-rings 4 for sealing are disposed at both ends of the spacer. The O-ring 4 is compressed by a sealing end plug 3 provided with a step-like groove that matches the size of the O-ring and an end plug 2 with a pressure medium introduction hole provided with the groove. The compressive force is generated by a screw structure provided at each end plug.

  The test piece assembly operation at the time of the test is that the O-ring 4 and the tubular spacer 5 are first loosely coupled to the end plug 2 and the end plug 3, and the outer diameter of the both end plugs is smaller than the inner diameter of the test piece tube material. These members can be inserted inside.

  After all the members are inserted, the end plugs are rotated with respect to each other, the screws are tightened, and the O-ring is compressed and deformed to close the gap between the inner wall of the test piece and the outer diameter of the end plug, thereby obtaining a high internal pressure sealed state.

  With such a structure, the high pressure medium 6 generated by a high pressure generator (not shown) is introduced into the inner surface of the test piece via the end plug 2 with the introduction hole.

  The test piece in the region sandwiched between the left and right O-rings is expanded by the pressure acting on the inner surface of the test piece, but the test piece region where the internal pressure does not act outside the O-ring position does not expand, so that the internal pressure sealing continues. The internal pressure until the end of the test is monitored with a pressure gauge (not shown), and the correspondence between the magnitude of the internal pressure and the deformation state of the test piece after loading is observed and evaluated.

  Since the appearance of the entire test piece assembled using the proposed internal pressure load mechanism is rod-shaped as shown in Fig. 1, the test piece is inserted into a small electric furnace or hot pot (not shown) during the high temperature test. did.

  In addition, this invention is not limited to said Example, For example, the O-ring cross-sectional shape in the said Example is not limited to a round shape, Other shapes may be sufficient. The same effect can be obtained even if the tubular spacer has an elastic deformation function.

  The present invention can be applied to a material strength test of an industrial steel pipe in addition to a tubular test piece such as a nuclear fuel-coated tube material having radioactivity for nuclear power generation.

1 ... tubular specimen,
2… End plug with pressure medium introduction hole,
3 ... end plug for sealing,
4 ... O-ring,
5 ... tubular spacer,
6 ... pressure medium,
10 ... O-ring,
11 ... End plug with pressure medium introduction hole,
12 ... End plug for sealing,
13 ... Tubular spacer,
14: External force load structure,
20 ... sealing material,
21 ... End plug with pressure medium introduction hole,
22 ... Seal compression pipe

Claims (1)

  Inside the tubular test piece, an O-ring is inserted and arranged at both ends of the tubular spacer, and two end plugs, a sealing end plug with a screw structure and an end plug with an internal pressure introducing hole, are mechanically formed with a screw structure. An internal pressure loading mechanism for a tubular test piece, characterized by comprising a mechanism that exerts a function of compressing the O-ring to close the gap between the inner wall of the tube and the end plug.

Images