JPS58109832A - Tensile testing device at low temperature - Google Patents

Abstract

PURPOSE:To realize a tensile test with high reliability, by heat-insulating a test piece at its testing area and jetting a cooled fluid to both holder parts to cool evenly the test piece. CONSTITUTION:A cooled fluid controlled down to a prescribed temperature is jetted through nozzles 12a and 12b, and a test piece 1 is cooled from its holding edge parts 1a and 1b through a testing area 4. Then holder plates 3a and 3b are moved up and down when the temperatures detected by temperature sensors 13a and 13b reach the set value, respectively. As a result, the tensile force is transmitted for a test while chucks 2a and 2b are being held tight. In such a way of test, the holding edge part responding to a tensile holding part A where heat intrudes easily from the outside is cooled. Thus the temperature distribution of the piece 1 can be assuredly equalized. At the same time, no breakdown arises at the holding edge part.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for performing a tensile test on test pieces made of various materials at low temperatures, and in particular, the present invention relates to an apparatus for performing tensile tests on test pieces made of various materials at low temperatures. This relates to a tensile testing device that is capable of conducting high tensile tests. Conventionally, this type of tensile testing device was the first
As shown in the figure, both holding end molecules tla of test piece +11
5 (11b is chuck +21as 121a, 12
1b, 121b and clamping plates (3)a, (3)b, and is held by the tension holding part A%A', and the same piece (
The test part (4) of 1) is immersed in a refrigerant (6) such as alcohol stored in an insulated container (5), and a nozzle (7) is inserted into the refrigerant (6) to remove the test piece ( 1) is provided with low temperature conditions.

The tensile test is carried out, for example, by fixing the clamping plate (3)b and pulling the other clamping plate (3)a upward in the direction of the arrow.
The tapered hole (8) of 1b narrows the chuck (2)a, 121b, and the V-shaped holding groove (9) shown in FIG.
) is formed in the 4-hole (l) which bites into the end of the test piece (1), and in the same figure, the lower holding end of the test piece (1) +1) b is Direct chuck +2
1 b , +21 b without being clamped by the connecting rod I that fits into the bottom of the insulating container (51 and protrudes downward), and the container Oυ is clamped by the chucks [21 b , 121 b In addition, when test 811) penetrates the insulating container (5), it is sealed with clay instead of the connecting rod aυ.

Since the conventional device has such a configuration, the chucks 121 a , 121 a , (2
1b, +21b, etc., and as a result, the upper and lower holding end portions 11a and tllb of the test piece are heated, creating a temperature gradient in the test piece (1), resulting in highly reliable test results. In addition, if the seal part is made of clay as described above, it is difficult to maintain a uniform temperature of the refrigerant (6) because liquid leakage occurs at low temperatures, and it is difficult to control the refrigerant (6) to a predetermined temperature itself. It is also fraught with difficulties.

Further, as shown in Figure 1, the test portion (4) of the test piece (1)
), the test purpose can be achieved by breaking from the part (4), but if the same thickness is used, the upper and lower holding ends are cut as described above. Part 11
1a and (1)b are under high temperature conditions, so they are in a weaker state than the parts under low temperature, and as a result, the retained end molecules il
There were serious defects such as breakage occurring from a, (1) and b, making it impossible to perform the original tensile test.5 The present invention was made to eliminate these drawbacks.
The purpose of the present invention is to provide a tensile testing device that does not create a temperature gradient in the test piece and therefore does not break at the holding end even if the test part and the holding end have the same diameter. The present invention will be explained with reference to an embodiment shown in FIG. 3 and below.
The configurations of the tension holding parts A and A' are exactly the same as those in FIG. Also, in the present invention, the upper and lower holding end portions of the test piece (1) +1
) a, 11) Nozzle (13a,
A cooling injection part B is provided for ejecting a cooling fluid made of a low concentration liquefied gas injected from the mackerel 1, and in the illustrated example, the nozzles 03a and QZb are checked 12) a.
.

(2) 3% (designed to be charged from the gaps 21b and 121b).

In this case, as the above-mentioned cooling fluid, for example, liquid nitrogen or nitrogen gas obtained by vaporizing it is preferably used.
), temperature sensors α3a and Q3b are attached to detect the temperature of the test piece +11, and the nozzle Ha%Q3
In order to automatically control the concentration of the cooling fluid from b, as shown in Fig. 5, the liquefied gas cylinder αη is connected to the nozzle α, 7J a sα via a heat exchanger using an electric heater, etc.
2b, the detection signal of the temperature sensor asa%03b is introduced into the temperature controller O, and the output of the temperature controller a9 is connected to p.
The current supplied to the electric heater of the heat exchanger (g) is controlled so that nitrogen gas or the like at the desired temperature set by the temperature controller a9 can be ejected as a cooling fluid from the nozzle α'Jasα7Jb. O Next, the above test part (4) is surrounded by a heat insulating part C, and the shown heat insulating part C is a heat insulating member Q41 that covers the test part (4), a heat insulating box a surrounding it, and both Q4.
It is composed of a heat insulating space (to) defined between 115 and 10. And in Fig.
1). In this case, the test area (4) inside the insulation box + 1!9 should be completely covered with the insulation material (141). If only part (4) of the specimen has a small diameter, apply a heat insulating material only to that part (4).
13a s Q3 b The end opening of the test part (
4) It is desirable to rub it so that it is placed in the vicinity of point 4).

Therefore, in order to conduct a test using the above device (well, first, a cooling fluid controlled to a predetermined temperature is injected from the nozzle (12a1azb), thereby cooling the test piece fil ii from its holding end portion +1la1ifllb to the test portion (4). 0 Then, when the temperature sensed by the temperature sensor (13'a, Q3b reaches the set value), the clamping plate (31a 5(
3) By moving b vertically, chuck +21
a, +21 b are narrowed as described above to obtain a test piece tl.
Hold the + holding end part [11a s ttl b firmly and rub it so that the tension force is transmitted from the force S Vh
As described above, according to the present invention, the test portion of the test piece is insulated and cooling fluid is injected into both holding end portions to cool the tensile holding portion, which is susceptible to heat intrusion from the outside. The holding end portion corresponding to A is cooled, which ensures uniform temperature distribution of the test piece, and the holding end portion does not become hotter than the test portion, so the specimen breaks from the holding end portion. This does not occur, and since the temperature of the test piece can be controlled by the temperature control of low-temperature liquefied gas, it is extremely easy to provide accurate temperature conditions.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view showing a conventional tensile test device, Fig. 2 is a perspective view of a chuck, Fig. 3 is a longitudinal sectional front view showing an embodiment of the device according to the present invention, and Fig. 4 is a longitudinal sectional front view showing another test device. FIG. 5 is a longitudinal sectional front view of the same main part in the case where a piece is used, and FIG. 5 is a circuit explanatory diagram showing the temperature side m system of low temperature liquefied gas attached to the cooling injection part of the apparatus. [11...Test piece (1) a, (11b... Ri holding part (4)
...Test tuna part 03a, α3b...Injection nozzle α3a, α3
b...Temperature sensor Q slope...Insulation member αω...Insulation box (A)...Insulation space A%A'...Tensile holding part B... ...Cooling injection part C...Insulation part Patent applicant representative Patent attorney Makoto Ito

Claims (1)

[Claims] +11 A tension holding part that holds both holding end portions of the test piece and applies tensile strength to the test piece, a heat insulating part that insulates the test portion of the test piece, and both holding end portions of the test piece. 1. A low-temperature tensile test device comprising: a cooling injection section that injects a cooling fluid of a predetermined temperature using low-temperature liquefied gas to the cooling injection section; (2) The low temperature according to claim 1, characterized in that the heat insulating part consists of a heat insulating member covering the test portion of the test piece and a heat insulating box surrounding the heat insulating member via a heat insulating space. Tensile test equipment.