JPH10281957A - Water pressure maintaining device for pipe tensile testing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain water pressure in a pipe by auxiliary-feeding pressurized water to the inside of the pipe so as to meet an increase in the inner volume of the pipe when tensile load is applied to the pipe. SOLUTION: A water pressure lid 2 on the fixed side is connected to one end of a sample pipe 1, and a water pressure lid 3 is 'connected to the other end. A power transmission member 17 is bridged between the water pressure lid 3 and a piston supporting part 14 for connecting respectively, and the sample pipe 1 is filled with water 18 for water pressure load. For tensile testing by applying tensile force to the water pressure lid 3, the sample pipe 1 extends so as to meet tensile load, and its elongation, or the travel amount of the water pressure lid 3 is transmitted to the piston supporting part 14 through a power transmission member 17. The piston supporting part 14, a piston 7, and a piston head 8 move by the same traveling amount, and a part of water 18 in a cylinder 4 is fed into the sample pipe 1 through a hose 5. The inside diameter of the cylinder 4 is equal to that of the sample pipe 1, therefore, the water 18 of the amount equivalent to the increment of the volume of the pipe based on the elongation of the sample pipe 1 by tensile strength is fed into the sample pipe 1, thereby permitting the water pressure in the sample pipe 1 to be maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for maintaining water pressure during a tensile test on a pipe.

[0002]

2. Description of the Related Art One pipe or a pipe connecting a plurality of pipes (herein, these are collectively referred to as "pipe") is closed and pressurized water is supplied to the inside thereof to reduce water pressure. A test may be performed in which the tube is subjected to a tensile load in the axial direction of the tube while being loaded.

[0003]

However, in such a case, the pipe expands by applying a tensile load to increase the internal volume thereof, and accordingly, the water pressure in the pipe decreases to maintain the expected water pressure. There is a problem that it is difficult to do.

Accordingly, an object of the present invention is to solve such a problem and to maintain the water pressure in the pipe even when a tensile load is applied to the pipe.

[0005]

According to the present invention, there is provided an apparatus for performing a tensile test on a pipe in a pipe axial direction while closing an end of the pipe and applying a water pressure to the inside thereof. In response to an increase in the volume in the pipe when a tensile load is applied to the pipe, means for supplementarily supplying pressurized water to the pipe is provided.

With such a configuration, when a tensile load is applied to the pipe in the axial direction while the end of the pipe is closed and water pressure is applied to the inside thereof, the volume in the pipe increases due to the tensile load. However, since the pressurized water can be supplementarily supplied into the pipe in response thereto, the water pressure in the pipe can be maintained at a desired value.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 denotes a test tube, which is constituted by a single tube or a conduit connecting a plurality of tubes. One end of the test tube 1 has a hydraulic cover 2.
And the other end is closed by the hydraulic lid 3. One hydraulic lid 2 is firmly fixed to the ground or the like. The test tube 1 is connected to the hydraulic lid 2 without being fixed to the ground or the like, and the hydraulic lid 3 is connected to the test tube 2 without being similarly fixed to the ground or the like. Then, a tensile force F in the pipe axis direction can be applied to the hydraulic lid 3 which is not fixed to the ground or the like.

[0008] A cylinder 4 is provided at a position opposite to the side to which the tensile force F is applied, in a direction of an axis coincident with the axis of the test tube 1. The cylinder 4 has an inner diameter equal to the inner diameter of the test tube 1. In addition, cylinder 4
Is firmly fixed to the ground or the like, like the hydraulic cover 2. The inside of the cylinder 4 and the inside of the test tube 1
The water transmission hoses 5 communicate with each other. The hydraulic lid 2 has a communication hole 6 formed therein.

A piston 7 is slidably provided inside the cylinder 4. As shown in FIG. 2, an O-ring 9 for sealing is provided around the piston head 8. The piston rod 10 slidably penetrates a cover plate 11 at the end of the cylinder remote from the test tube 1. It is fixed to the end flange 12 by welding or the like.

The distal end 13 of the piston rod 10 is connected to a piston support 14. As shown in FIG.
The piston support 14 includes a support block 15 and a cylindrical piston receiver 16 protruding from the support block 15.
And are integrally provided. Tip 13 of piston rod 10
Is positioned by being inserted into the piston receiver 16 of the piston support portion 14 and is received by the support block 15.

The support block 15 of the piston support 14
A power transmission member 17 is provided between the power transmission member 17 and the hydraulic lid 3. The power transmission member 17 is composed of a plurality of rods or plates provided along the periphery of the test tube 1 and the cylinder 4, one end of which is connected to the support block 15, and the other end of which is a hydraulic cover. By connecting to the test tube 1, the distance between the hydraulic pressure lid 3 and the piston support 14 along the axial direction of the test tube 1 and the cylinder 4 can be changed.

In this state, the test tube 1, the cylinder 4, and the hose 5 are filled with pressurized water 18 for applying a water pressure to the test tube 1.

In such a configuration, when a tensile test is performed on the test tube 1 in a state where a water pressure is applied to the inside of the test tube 1, the test tube 1 is loaded into a test location shown in the drawing, and one end thereof. Is connected to the hydraulic cover 2 on the fixed side, and the hydraulic cover 3 is connected to the other end. Then, the power transmission member 17 is moved between the hydraulic cover 3 and the piston support portion 14 to perform connection. After that, pressurized water 18 for hydraulic load is injected and filled into the test tube 1 and the like.

If a tensile force F is applied to the hydraulic lid 3 in this state, the test tube 1 can be subjected to a tensile test in the tube axis direction while applying a hydraulic pressure to the inside of the test tube 1. At this time, the test tube 1 elongates in response to the tensile load, and the amount of the elongation, that is, the amount of movement of the hydraulic lid 3 is transmitted to the piston support 14 via the power transmission member 17. Then, the piston support portion 17 and the piston 7 move by the same amount as the above-described movement amount, and the movement of the piston head 8 causes a part of the water 18 in the cylinder 4 to pass through the hose 5 to the inside of the test tube 1. Supplied immediately.

At this time, since the inner diameter of the cylinder 4 is equal to the inner diameter of the test tube 1 as described above, the internal volume of the test tube 1 increases due to the elongation of the test tube 1 due to the tensile force F. A supplementary supply of pressurized water 18 in an amount equal to? As a result, even though the test tube 1 is elongated by the tensile force F, the water pressure inside the test tube 1 can be maintained at an expected value.

[0016]

As described above, according to the present invention, in a device for performing a tensile test on a pipe in the axial direction while closing the end of the pipe and applying a water pressure to the inside thereof, a tensile load is applied to the pipe. A means for supplementally supplying pressurized water to the pipe is provided in response to the increase in the volume of the pipe when given, so that the water pressure in the pipe is maintained at an expected value regardless of such an increase in the volume. Can be.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a water pressure maintaining device during a tensile test of a pipe according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of the cylinder in FIG.

FIG. 3 is an enlarged view of a piston support portion in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Test tube 2 Hydraulic lid 3 Hydraulic lid 4 Cylinder 5 Water transmission hose 7 Piston 14 Piston support part 17 Power transmission member F Tensile force

Claims (1)

[Claims] 1. An apparatus for performing a tensile test on a pipe in a pipe axial direction while closing the end of the pipe and applying a water pressure to the inside of the pipe, and increasing the volume in the pipe when a tensile load is applied to the pipe. 2. A device for maintaining a water pressure at the time of a tensile test on a pipe, wherein a means for supplementarily supplying pressurized water to the pipe is provided.