SU761875A1 - Apparatus for low-temperature mechanic testing for tension-compression - Google Patents

Description

The invention relates to. Testing equipment, namely, devices for low-temperature mechanical testing "and tensile compression.

A device for low-temperature mechanical tensile-compression tests containing a cryostat with a working chamber, a support tube and a thrust installed coaxially inside it, introduced into the working chamber, and the specimen grips connected to the support th bar [1] are known.

The disadvantage of this device is the high consumption of cryogenic liquid.

The aim of the invention is to reduce the consumption of cryogenic liquid.

This goal is achieved by the fact that the thrust and the support pipe are made of composite lengths, and the device is equipped with shells with vacuumized cavities made of elastic thermally insulating material and fixed on the corresponding parts of the thrust and support pipe in place of their connector, but; In addition, in order to eliminate sample distortions during loading, the ends of the upper parts of the thrust are made with a comic sample, and the ends of the lower part of the thrust and the support tube have a shape corresponding to the sampling form.

The drawing shows a diagram of the proposed device.

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The device contains a housing 1, a working chamber 2 for introducing a liquid refrigerant, a pipe 3 for pouring the latter, 'grips 4 and 5 for sample 6, a radiation screen 7 for cooling of which a nitrogen bath 8 is installed, a yoke 9 to which the body is sealed 1, the cradle and the support tube, made of composite parts of 10, 14 and 12, 43 lengthwise, shells 44 and 15 with evacuated cavities 16 and 17, made of elastic thermally insulating material. The shell 14 is fixed, between the upper 10 and lower 11 parts of the thrust, and the shell 15 between the upper part 12 of the support tube and the sleeve 18, mounted on the lower part 13 of the support tube. The ends of the upper parts 10 and 12 of the thrust and the support pipe are made with a conical sample, and the ends of the lower part 11 of the thrust and sleeve 18 have a shape corresponding to the shape of a conical sample. Cavities 16 and 17 are provided with pipelines 19, 20 and 21.

The device works as follows.

/ When removing the case 1, the test sample 6 is set in grips 4 and 5.

After that, the cross-member 9 is attached to the housing 1, the working chamber 2 of which is pumped out to obtain the necessary vacuum

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761875

. and fill the heat exchange gases. In the van, liquid nitrogen is poured in to cool ради radiation of radiation screen 7 and Preliminary -. cooling of the parts inserted into the working chamber 2. Then, cryogenic “Liquid

(for example, helium), so that test sample 6 was completely immersed in it. At the same time between the sleeve 18 and the upper part 12 of the support pipe; and also between the upper 10 and lower 44 parts of the gap there are gaps communicated with cavities 17 ή 16, pumped out to a high vacuum through pipelines 19, 20 and 21 ......

At the end of the pouring process, all parts introduced into the working chamber 2 are cooled with liquid helium and its vapors to a temperature close to that of liquid helium. Then the motion of the upper part 40 of the thrust begins with the grip 5 upwards. This stretches the spring 22 between (the upper 10 and lower 11 parts of the thrust and reduces the spring 23 between the upper 12 and lower 13 parts of the support pipe. After the sleeve 18 contacts the top part of the support pipe 42, this sleeve is precisely centered on the conical sample of the top 12 ¹ pipe, and the lower part 11 of the thrust is precisely centered on the conical sample of the upper part 10. Thrust is applied to the sample, under the action of which it collapses.

After the sample is destroyed and the cryogenic liquid residues evaporate, the housing 1 is removed and the destroyed sample is removed from it.

Due to the presence of evacuated cavities 16 and 17, the heat influx from the upper part 10 of the thrust of the upper part 12 of the supporting tube into the working chamber 2, which is filled, is almost completely excluded. refrigerant. Due to the practical absence of heat transfer into the working chamber 2, the intrusive evaporation of the refrigerant is eliminated, the sizing process is significantly reduced in time. .meni

Thus, the design of the device “Eubesp'ochiva’? R ^ "" ®Achieve. A definite decrease in the flow rate of cryogenic liquid when pouring it into the working chamber and during the tests.

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Claims (2)

Claim 1. Device for low-temperature mechanical tests for tensile 15 compression, containing a cryostat with a working chamber, a support pipe and a thrust installed coaxially inside it, inserted into the working chamber, and the specimen hinge connected to the support and the supporting pipe differing from 20 I have the fact that, in order to reduce the consumption of cryogenic. liquids, thrust and support pipe are made 'composite in length, and the device is equipped with shells with evacuated ’cavities made of elastically insulated heat-insulating material and fixed to the corresponding parts of the thrust and support pipe at the place of their connector. 2. Device by π. 1, about tl and ch yu eu ;; With the fact that, in order to eliminate the distorted specimen of the sample under loading, the ends of the upper parts of the thrust and the support pipe are made with a conical sample, and the ends of the lower part of the thrust and the support pipe have a shape corresponding to the shape of the samples. ............,. .. . Source .. Information adopted in attention during examination: . _______ I · Vinogradov Η. P. and others. Installation for lowcotem, peratur; Attempted materials in creep modes and. active loading. - “Factory Laboratory”, 1975, No. 4, p. 488-490 (prototype). ''. .-.four.",,. . ^ WORLD * ’* '. * · * · * · *' * ***) · V - · ν ~ -Y-X-g-V, ~ M /„ 761875