JPS6035009B2 - Sample deformation measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sample deformation measuring device for determining the deformation that occurs in a sample during a durability test of a cylindrical material such as a metal pipe or other sample.

In the durability test mentioned above, there is a pressure difference between the test and the atmosphere.
Moreover, it is generally carried out at high temperatures and in a special atmosphere filled with corrosive gas.

At this time, if a displacement detector that measures the amount of deformation occurring in the sample is installed in the same atmosphere, the detector will not be able to withstand long-term use. For this reason, it is generally considered to measure the amount of deformation caused in a sample by applying pressure with a pressurizing device in a chamber maintained in a special atmosphere using a detector provided outside the chamber. In this case, in order to maintain airtightness inside and outside the chamber and to transmit the deformation of the sample to the detector, the displacement transmitting section is inserted through the closed opening in the chamber, and the gap between the opening and the member is closed with a bellows. However, if this is done simply, the displacement force caused by the bellows, which is deformed by the pressure difference inside and outside the chamber, may be applied as an undesirable force to the sample or detector via the transmission member. become.

Therefore, various methods have been devised to counteract this undesirable force generated in the transmission member.

One of them is shown in Japanese Patent Publication No. 40-510y, which is a system between each hole and a displacement transmitter inserted into one of the holes in the corresponding position of the opposite wall of the vacuum chamber. By providing a bellows that closes the hole, the bellows is deformed due to the pressure difference between the inside and outside of the chamber, and the forces transmitted to the transmission member tend to act in opposite directions, thereby preventing undesirable displacement force on the transmission member due to the pressure difference. I try not to work. However, this conventional method cannot completely reduce the displacement force to zero if there is any variation in the pair of bellows.
Furthermore, if the indoor atmosphere is kept at a high temperature, the length of the transmission member changes due to linear thermal expansion depending on the temperature, which poses a problem in that it adversely affects accurate measurement of the amount of deformation of the sample. The present invention has been made in order to solve the above-mentioned conventional problems, and its purpose is to provide a sample deformation amount measuring device that can accurately measure the amount of deformation of a sample under a special atmosphere. is to provide.

Hereinafter, an example of measuring the amount of deformation in a pressure test of a metal pipe at a temperature of 12,000 to 13,000, below atmospheric pressure, and in an atmosphere filled with corrosive gas will be described with reference to the drawings.

1 is a metal pipe that is a sample, and inside it is a ○ ring 2.
The pressurizing device 3 is iron-inserted through the pressurizing device 3.
A circumferential groove 3a is formed on the outer periphery, and the outer periphery of the circumferential groove 3a is sealed from the outside with a sealing material 4.

3b is a flow path into which a pressure fluid such as oil flows in from the direction of the arrow.

Therefore, with these configurations, if pressure is applied by flowing pressure fluid into the flow path 3b, the outer peripheral side of the sealing material 4 will become metal/
It begins to press on the inner part of Guipoo. 3c is a threaded member 35 that protects the displacement detection bar 5 whose temperature expansion coefficient is close to zero, and a protective tube 6 whose temperature expansion coefficient is close to zero.
It is held through the arm.

The above components are kept at a temperature of 120°C to 130qo.
, placed in a chamber 7 in an atmosphere below atmospheric pressure and filled with corrosive gas. Reference numeral 8 denotes a furnace wall constituting the outside of this chamber 7.

Reference numeral 9 denotes a measurement chamber in which air is removed from the pipe 10 and the inside pressure is maintained at the same pressure as that of the chamber 7. It's hanging.

Inside this measurement chamber 9, a displacement detector 12 such as a Magnescale for measuring the expansion/contraction distance of the rattan 12a which is extended by an internal spring in the direction of the arrow is provided in a state where it is cooled by a water jacket 36. is brought into contact with the cap 13 of the detection bar 5 by the internal spring at a desired pressure of, for example, 45 mm. 14 absorbs the relative displacement between the protection tube 6 and the detection bar 5, and also prevents the corrosive gas and temperature in the chamber 7 from having an adverse effect on the displacement detector 12 in the measurement chamber 9. A bellows is provided between the protective tube 6 and the cap 13.

The inner periphery of a flange 15 is attached to the protective tube 6 in an airtight manner, and the flange 15 is pressed against the outer wall of the measuring chamber 9 via a ring 17 by bolts 16, 16.

An O-ring 2 is attached to the flange 21 attached to the furnace wall 8.
2, another flange 23 is attached with bolts 24, 24, and this flange 23 is provided with bolts 25 for temporary fixing when the flange 5 and measurement chamber 9 are suspended from the mounting body 11, and for guiding horizontal movement. is installed. Then, flanges 15 and 2 on the outer side of the protection tube 6
3, a second bellows 37 is installed so as to absorb the influence of thermal expansion and contraction of the furnace wall 8 on the measurement chamber 9 and to keep the chamber 7 airtight. on the other hand,
A hydraulically driven actuator 26 controls the pressure of the pressurizing device 3 by controlling the pressurizing piston 28 by the servo valve 27 to change the pressure of oil in the pressure chamber 26a. This control adds the setting signal from the pressure setting signal source 29 to the point 3
The actual pressure in the pressurizing chamber 26a is detected by the pressure detector 32 and sent to the summing point 3 via the amplifier 33.
Since the river is returned, the entire system is servo-controlled, so that the set pressure can be accurately applied to the pressurizing portion of the cylinder 3a of the pressurizing device 3. In the above configuration, in order to perform a pressurization test, first wait until the temperature of the chamber 7 stabilizes and the deformation of each part due to thermal expansion settles down to a constant state.
After reaching this state, the displacement reference of the displacement detector 12 is determined, for example, by setting it to zero. At this time, the detection bar 6 is moved by a slight pressure of the shaft 12a of the displacement detector 12.
The right end thereof is in contact with the outside of the metal pipe 1 corresponding to the internal pressurized portion. Next, in this state, the pressurizing device 3
When pressure fluid is supplied to the flow path 3b by the actuator 26, the pressure in the pressurized part consisting of the circumferential groove 3a and the sealing material 4 increases, and this pressure is applied only to the part of the metal pipe 1 that is in contact with the sealing material 4. It becomes like this. For this reason, the inside of the metal/guipoo is locally pressurized. When the metal pipe 1 is deformed by this pressurization, the detection bar 5 is pushed to the left, and the shaft 12a of the displacement detector 12 is pushed to the left via the cap 13, causing the movement of this shaft 12a. An electric signal corresponding to the amount is output from the displacement detector 12. At this time, the pressure of the chamber 7 is applied to the inside of the first bellows 14, but since the inside of the measurement chamber 9 is kept at the same pressure as the chamber 7, no pressure difference is created there, and no adverse effects appear. Furthermore, the presence of the first bellows 14 completely separates the inside of the measurement chamber 9 from the inside of the chamber 7, and there is no fear that corrosive gas or temperature inside the chamber 7 will have an adverse effect on the displacement detector 12. In addition, in order to perform a deformation test on the pipe 2, the pressure setting signal source 29 should be replaced with a displacement setting signal source, the switch 34 should be switched to the dashed line side, and the signal from the displacement detector 12 should be fed back negatively. good.

Further, the pipe 2 is not necessarily limited to metal, and the test object can be cylindrical materials made of various other materials, and is not limited to cylindrical materials. Furthermore, the pressurized fluid to be applied to the pressurizing section of the pressurizing device 3 is not limited to oil, but may be water, air, or other fluids. As described above, the device according to the present invention includes a tube that is inserted into an opening □ raised in the wall of a chamber maintained in a special atmosphere and has one end fixed to a fixed point inside the chamber, and A measurement chamber provided at the other end, the interior of which is maintained at the same pressure as the inside of the chamber, a displacement detector housed and fixed within the measurement chamber, and formed of a material having approximately the same coefficient of thermal expansion as the tube. A detection bar is inserted into the tube and has one end attached to the outer side of the sample in the chamber and the other end attached to the axis of the displacement detector in the measurement chamber, and a connection between the tube and the detection bar. A first bellows that blocks a gap between the chamber and a second bellows that blocks a gap between the chamber and the tube.

Therefore, due to the action of the first bellows and the measurement chamber, which is kept at the same pressure as the inside of the chamber, the undesirable displacement force acting on the detection bar is canceled out, and since it is a single bellows, it is not possible to There is no problem caused by imbalance between the bellows.

In addition, the effect that the change in length due to thermal linear expansion of the detection bar has on the detector is due to the thermal linear expansion of the tube made of materials with approximately the same coefficient of thermal expansion and under approximately the same conditions. This is canceled out by displacing the entire chamber in the same direction, making it possible to accurately measure the deformation of a sample in a special atmosphere without being affected by the special atmosphere outside the special atmosphere. become able to.

[Brief explanation of the drawing]

The figure is a sectional view of a device showing an embodiment of the present invention. 0 1... Metal pipe, 3... Pressure device, 3a... Circumferential groove, 4... Seal material, 5...
Detection bar, 12... Displacement detector.

Claims (1)

[Claims] 1 A device that measures the amount of deformation caused in a sample by pressurizing it with a pressurizing device outside the chamber, which is maintained in a special atmosphere with a pressure difference between the chamber and the atmosphere and a temperature higher than room temperature. a tube inserted into an opening made in the wall of the chamber and having one end fixed to a fixed point inside the chamber; and a tube provided at the other end of the tube outside the chamber, the inside of which is at the same pressure as the inside of the chamber. a measurement chamber kept at a temperature of A detection bar whose other end is in contact with the shaft of the displacement detector in the measurement chamber, a first bellows for blocking a gap between the tube and the detection bar, and an opening of the chamber are disposed on the outer side. and a second bellows that blocks a gap between the tube and the tube.