JPH01216227A - Weight load type creep testing machine - Google Patents

Abstract

PURPOSE:To preclude a decrease in the accuracy of a test result due to variation in load by automating the unloading or loading operation of a weight and suppressing accompanying load variation. CONSTITUTION:A loading mechanism A is provided inside a lower frame 1, a test piece clamping mechanism B is provided inside an upper frame 2, and an impact preventing mechanism C is provided on the upper frame 2. An atmosphere chamber 4 is fixed inside the upper frame 2 at the position of the test piece clamping mechanism B through a bracket 3, and a test piece 8 whose upper and lower ends are clamped by an upper pull rod 5 and a lower pull rod 6 is mounted therein. A load is placed on the test piece 8 and its elongation is measured by optical tensometers 9a and 9b. At the position of the impact preventing mechanism C, a screw rod 12 is moved up and down through a worm gear 15 which is driven by a motor 16 to interpose an annular spring type scrimeter 18 between the worm gear 15 and upper frame 2, thereby absorbing an impact due to load variation when the test piece 8 is applied with the load.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an FFI weight loading type creep testing machine, and in particular automates the unloading or loading of the weight to suppress the accompanying load fluctuations and This invention relates to a weight loading type creep tester that suppresses a decrease in the accuracy of test results caused by fluctuations.

[Conventional technology]

In general, creep tests using variable loads require that a very stable constant load be applied to the specimen in stages, increasing the load in stages. A weight-loading type testing machine that divides the load into two parts is often used.

This type of creep test machine prepares in advance a plurality of weights with slightly different amounts of ffi, and combines these weights to create various loads. The test specimen is subjected to a load that increases as the load increases.

[Problem to be solved by the invention]

However, in conventional creep testing machines, the work of changing the weights to create various loads must be done manually, which is a problem in that the work is complicated and labor-intensive. In addition, since the work of changing the weight is carried out during the creep test, there is a problem in that changes in load and impact caused by changing the weight cause disturbance to the test piece, which adversely affects the test results.

That is, the weight is changed in stages as shown in FIG. 3, and at the points pHP2 and P3 where the load is changed, various fluctuations occur as shown by dotted lines.

To explain using the position of point PI as an example, load il! When changing from ID to load E, two methods are used: -load ff1rF is removed and then load F+G is added, or -load iiG+H is added and load H is removed. In any case, there is a problem in that a large variation in load occurs, and this variation adversely affects the test results as described above.

Furthermore, with this type of testing machine, the position at which the weight is hung lowers as the test piece stretches; however, in order to obtain accurate test results, it is necessary to change the position at which the weight is hung to the neutral position during the test. It is necessary to return it to its position. When performing this work, conventional methods have the same problems as above in that they require labor and are accompanied by load fluctuations.

An object of the present invention is to provide a weight-loading type creep tester that solves the problems of the conventional techniques described above, allows easy work of loading a weight, and causes less load fluctuation during the load-loading operation. It is in.

[Means to solve the problem]

In order to achieve the above object, the present invention connects a hanging rod to the lower end of a test piece, and unloads or loads a plurality of FFI weights onto a plurality of weights attached to the hanging rod while performing the test. In a weight loading type creep tester designed to perform a creep test on a piece, a threaded rod is connected to the upper end of the test piece,
This threaded rod is supported so as to be able to move up and down via an annular spring-shaped force meter, and each of the plurality of weights is supported at the end of a lever that swings due to the rotation of a cam. The present invention is characterized in that the weight can be automatically unloaded or loaded onto the weight plate.

[For production]

According to the present invention, the lever swings by rotating the cam, and as the lever swings, the weight supported at the end of the lever is dynamically unloaded or loaded from the weight plate. . The variation in load that occurs when the weight is unloaded or loaded is absorbed by the annular spring type force meter.

〔Example〕

Hereinafter, one embodiment of the weight loading type creep tester according to the present invention will be described with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 indicates a lower frame, and an upper frame 2 is fixedly installed on the lower frame 1. As shown in FIG.

Then, inside the lower frame 1, a load applying mechanism A is installed.
Further, a test piece holding mechanism B is provided inside the upper frame 2, and a shock prevention mechanism C is further provided on the upper frame 2.

At the middle test piece holding mechanism B, an atmosphere chamber 4 is fixed to the inside of the upper frame 2 via a bracket 3, and inside this atmosphere chamber 4, an upper pull rod 5 and a lower pull rod 6 hold the upper and lower ends. Test piece 8
is installed.

A load is applied to this test piece 8, but its elongation is measured by optical extensometers 9a arranged in pairs on both sides of the chamber 4.
It is designed to be measured at s 9b. Incidentally, bellows 10 and 11 are attached to the top and bottom of the chamber 4 to seal the inside of the atmosphere chamber 4 and the atmosphere.

In addition, in the upper impact prevention mechanism C, a threaded rod 12 extending through the upper frame 2 is connected to the upper end of the upper pull rod 5 via a load cell 13.
A worm gear 15 is screwed into the upper end of the threaded rod 12. This worm gear 15 has a pulse motor 16
are connected to each other, and when the motor 16 is driven, the threaded rod 12 is moved up and down via the worm gear 15.

An annular spring-shaped power testing needle 18 is interposed between the worm gear 15 and the upper frame 2, and this power testing needle 18 bends when the upper pull rod 5 is pulled up, and then a load is applied to the test piece 8. When the upper pull rod 5 is pulled down, the power detection needle 18 absorbs the shock caused by the load fluctuation at that time.

On the other hand, in the lower load loading mechanism A, a hanging rod 2 is connected to the lower end of the lower pull rod 6 via a connecting frame 20.
1 is connected, and to this hanging rod 21, as is clear from FIG. 2, 11 stages of weight devices 23 are connected. A pair of weights 25 are disposed above the weight device 23, and the weights become progressively heavier as they move towards the C stage.One end of a lever 27 is connected to the weight 25 via a support 26 so as to be freely engageable. has been done. In addition, the support body 26 is ff1M! 25, and a hook 26b that can be freely engaged with the pin 26a.

This lever 27 is swingably supported via a hinge 28, and a pair of upper and lower sensors 29, 29 for detecting the swinging of the lever 27 is disposed near the other end of the lever 27. Furthermore, the lever 27 is configured to be pushed down via a cam 30, and this cam 30 is configured to be rotationally driven by a motor 31.

The weight 25 is the 11-stage weight device 23 as described above.
There are 11 pieces prepared corresponding to the above weights, and their weights are set using a binary system, so that about 2000 types of loads can be created by arbitrary combinations.

In addition, a stopper mechanism 33 is provided at the bottom of the topmost weight device 23.
are connected to each other, and this stopper mechanism 33 is connected to the weight device 23.
It is configured to limit the lower and upper limits of the vertical movement of , and the gap g is extremely small.

Next, the operation of this embodiment will be explained.

First, the test piece 8 sandwiched between the lower upper pull rod 5 and the lower pull rod 6 was installed in the atmosphere chamber 4, and then a weight #I25 was sequentially applied to the test piece 8, as shown in FIG. A stepwise increasing load is created, and the elongation of the test piece 8 over time is measured using an optical extensometer 919b. This is a creep test using a so-called capsular dynamic load.

According to this embodiment, ff1M! 25 gradually become heavier toward the bottom, so load them sequentially starting from the top, or replace the ones in the top tier one by one. This makes it possible to create a load of about 200 of 4 class.

To replace the weight 25, it is sufficient to rotate the cam 30 through the motor 31, and this replacement can be detected by the sensors 29 and 29, so that the weight 25 is automatically changed. It can be placed on the weight 1rII 23 and taken off from there, and the trouble required for adding and removing the weight 25 can be eliminated.

In addition, the load fluctuation (Fig. 3) caused by the above-mentioned repositioning of the weight 25 will be absorbed by the above-mentioned annular spring-shaped detection force = [18], which will result in a smooth load change. This variation does not adversely affect the measurement results of the optical extensometers 9a and 9b, and highly accurate measurement results can be obtained.

Furthermore, when changing the load on the weight 25, the weight device 23 may temporarily drop suddenly, but since the stop mechanism 33 is connected to the bottom of the weight device 23, the sudden drop will not occur. is also mechanically limited, and when the stop mechanism 33 is actuated, the impact is absorbed through the annular spring-shaped force detection needle 18 in the same way as described above, so that a smooth load change is achieved. It goes without saying that this operates in exactly the same way even when there is a temporal overload.

On the other hand, when the weight 25 is subjected to a varying load, the weight device 23 is lowered as the test piece 8 stretches, and the load position of the weight 25 is lowered.

At this time, according to this embodiment, the support needle 35 fixed to the connecting frame 20 moves downward, so this movement is detected by the sensor 36, and the pulse motor 16 is operated based on this detection signal, causing the screw Since the rod 12 is pulled up, the weight loading mechanism A and the test piece 8 are always maintained at the intermediate position.

If this intermediate position cannot always be maintained, the optical axis of the optical extensometers 9as, 9b must be adjusted each time. In other words, in the conventional system, it was necessary to adjust the zero point every time the weight 25 was changed and loaded, but according to this embodiment, the intermediate position is automatically maintained, making such extremely troublesome adjustment unnecessary. Become.

Further, since the displacement of the weight loading mechanism A in the vertical direction can be reduced, the structure can be made simple and compact, and the impact caused by falling when the test piece 8 breaks can be reduced.

Furthermore, as is clear from FIG. 2, the connecting frame 20 is connected to the lower bellows 11 for sealing with the atmosphere, but each time the weight 25 is changed and the load is changed, the pulse motor 16 is Since the zero point is adjusted through the bellows 11, the bellows 11 hardly expands or contracts, and there is no need to correct errors in reaction force due to fluctuations in the spring constant of the bellows 11.

As a result, it is no longer necessary to use a high-grade welded bellows or the like for the bellows 11, and an inexpensive molded bellows can be used, making it possible to make the bellows 11 excellent in both economy and durability.

In addition, with conventional devices, for example, it was difficult to reduce the initial load to zero, such as glEil of the hanging part of the weight loading mechanism A, but with this, the bellows 11, which has a relatively large spring constant,
can be used, the weight of the lower part of 1α can be balanced to make the initial load zero, and the accuracy of measurement can be improved.

Although the present invention has been described above with reference to one embodiment, it goes without saying that the present invention can be applied to all types of creep testing machines such as lever type, compression type, and popular test type.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, a threaded rod is connected to the upper end of the test piece, and this threaded rod is supported so as to be vertically movable via an annular spring-shaped lateral force meter. Each weight is supported at the end of a lever that swings as the cam rotates, and the swing of this lever allows the weight to be automatically unloaded or loaded onto the weight plate, so @the weight is automatically Once the load is applied, load fluctuations caused by changes in load are reliably absorbed, allowing highly accurate creep test results to be obtained.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an embodiment of a weight loading type creep tester according to the present invention, Fig. 2 is a front view for explaining the structure thereof, and Fig. 3 is a front view showing an embodiment of the weight loading type creep tester according to the present invention. FIG. 4... Atmosphere chamber, 8... Test piece, 12...
Threaded rod, 16... Pulse motor, 18... Annular spring type lateral force meter, 21... Hanging rod, 23... Weight plate, 2
5... Weight, 27... Lever, 30... Cam, 3
3...stopper mechanism. Applicant's agent Mr. Sato Figure 1 Figure 2 Time Figure 3

Claims (1)

[Claims] 1. A hanging rod is connected to the lower end of the test piece, and a creep test is performed on the test piece while unloading or loading a plurality of weights on a plurality of weight plates attached to the hanging rod. In the weight loading type creep tester, a threaded rod is connected to the upper end of the test piece, and this threaded rod is supported so as to be vertically movable via an annular spring-shaped force meter, and the plurality of Each weight is supported at the end of a lever that swings by rotation of a cam, and the weight can be automatically unloaded or loaded from the weight plate by swinging the lever. A weight loading type creep tester. 2. The weight loading type creep testing machine according to claim 1, wherein the threaded rod is configured to be able to rise freely by a distance corresponding to the elongation of the test piece. 3. The weight-loaded creep test according to claim 1, wherein a stopper mechanism for restricting vertical movement of the weight plate is provided at the bottom of the lowest weight plate among the weight plates. Machine.