JPH02226040A - Apparatus for creep test - Google Patents

Abstract

PURPOSE:To always apply a correct load for creeping test by providing a correcting spring which is coupled at one end thereof to a horizontal lever and at another end thereof to a testing tank. CONSTITUTION:Simultaneously when a bellows 35 is extended, a correcting spring 36 is stretched. Accordingly, a load error K.delta(kg) is automatically corrected. Supporting that a spring constant of the correcting spring is K/R(kg/ mm) and an extension thereof is delta(mm), a correcting load by the extension of the correcting spring 36 is K/R.delta(kg). When a moment around a supporting member 21 is taken into consideration, an equation K.delta.x=K/R.delta.Rx holds. Therefore, the load error K.delta balances with the correcting load K/R.delta, thereby realizing accurate correction of the load error.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a creep testing device, and more particularly to a creep testing device that can always apply an accurate load to a test piece.

[Conventional technology]

2. Description of the Related Art Generally, a creep test apparatus is known that performs a creep test while heating a test piece in an atmosphere such as a vacuum or an inert gas. This type of creep testing device is often used for creep testing of test pieces of nuclear materials and new materials. Conventional creep test equipment is configured to place a test piece in a test tank, apply a tensile load to the test piece from outside the test tank via a pull rod, and perform a creep test according to this load. . A stretchable bellows for maintaining airtightness within the test tank is interposed in the portion of the test tank through which the pull rod passes.

By the way, in the conventional type, the spring force changes in proportion to the spring constant of the bellows each time the bellows expands and contracts, so when applying a tensile load to the test piece over a long period of time, it is necessary to constantly apply tension to the test piece. There is a problem that it becomes impossible to continue applying a load with high accuracy.

Therefore, by the amount that the spring constant of the bellows changes,
It becomes necessary to correct the tensile load, but in the past,
A horizontally movable weight may be provided, and the weight may be horizontally moved to balance the change in the spring constant of the bellows, or a horizontally movable weight may be provided to adjust the spring constant of the bellows. A method has been proposed in which the weight is oscillated left and right by the amount that the constant changes to maintain balance.

[Invention or problem to be solved]

However, among the above-mentioned conventional means, those equipped with horizontally movable weights have a problem that the mechanism is too complicated, and those with horizontally movable weights are difficult to handle the tensile load. There is a problem that accurate correction cannot be performed.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a creep test device that solves the problems of the above-mentioned conventional techniques, has a simple structure, and enables highly accurate correction.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a frame, a test tank supported by the frame so as to be able to move up and down, and a pull rod that can move up and down to apply a tensile force to a test piece held in the test tank. , is interposed between the pull rod and the test chamber, and includes a telescopic bellows that maintains airtightness inside the test chamber, and a bellows that is swingably supported by the frame via a support member, and a bellows at one end. In a creep test device comprising a horizontal lever to which the pull rod is connected by a pin and a creep test weight is suspended from the other end, a correction spring is used to correct a load error caused by expansion and contraction of the bellows. The present invention is characterized in that one end of the correction spring is connected to the horizontal lever, and the other end of the correction spring is connected to the test tank.

[For production]

According to the present invention, when a creep test is performed and the test piece stretches, the water lever tilts due to the weight of the creep test weight, so this tilt can be corrected to maintain the horizontal lever horizontally. Then, the test chamber is lowered. Then, the bellows interposed between the test chamber and the pull rod expands, and a load error occurs due to the product of this expansion and the spring constant of the bellows. That is, even if the creep test weight continues to be loaded, the load will not be applied by the amount of the load error, and there is a possibility that the leap test cannot be performed accurately. However, according to this embodiment, since the correction spring is extended at the same time as the bellows is extended, a correction load is generated by the product of this extension and the spring constant of the correction spring, and the above load error is compensated for. will be corrected.

〔Example〕

Hereinafter, an embodiment of the creep test apparatus according to the present invention will be described with reference to the accompanying drawings.

In the figure, reference numeral 1 indicates a box-shaped frame. A test tank 2 is provided in the frame 1, and a heating furnace 3 is arranged around the test tank 2. This exam WJ
A lifting flange 5 is fixed to 2, and this lifting flange 5
A pair of threaded rods 6°6 are screwed together. The threaded rods 6, 6 are rotatably supported at their upper and lower ends by bearings 7, 8, and have sprockets 9, 9 at their lower ends.
fJ< is fixed, and a sprocket 11 of a lifting motor 10 is connected to the sprockets 9, 9 by a chain.

Further, a test piece 12 is mounted inside the test tank 2. The lower end of this test piece 12 is supported by a support rod 13,
The support rod 13 has a reaction force receiver fixed to a member 15, and the reaction force receiver 15 is fixed to a cover plate 16. The lid plate 16 is bolted to the upper end of the test W12 so as to close the opening of the test tank 2. In addition, a hole 18 through which a pull rod 17 passes is bored in the cover plate 16, and the pull rod 17 extends downward through the hole 18, and the upper end of the test piece 12 is supported at the lower end of the hole 18. There is. Also, the upper end of the pull rod 17 is connected to the intermediate rod 1
9, this intermediate rod 19 extends upwardly and is pin-connected to a horizontal lever 20 via a stop 19a.

This horizontal lever 20 is supported by a support member 21 fixed to the frame 1 so as to be able to swing freely about the support member 21, and a weight for creep testing is attached to one end of the horizontal lever 20 via a hanging member 22. A weight 23 is suspended. A block 24 is located below this weight 23, and a rubber damper 25 is placed on top of this block 24 to stop the weight 23 from falling when the test piece 12 breaks. It looks like this. Further, a support needle 27 is fixed in the middle of the hanging member 22, and the inclination of the horizontal lever 20 is detected by the support needle 27 and a photo sensor 28. Furthermore, a balance weight 29 is attached to the other end of the horizontal lever 20, and zero balance is maintained by this balance 'M29.

Further, one end of a lobe 30, 30 is fixed to the lid plate 16, and the other end of this lobe 30 is attached to a roller 31, 31...31.
is wound and pulled out of the frame 1, and a counter weight 32 is attached to the other end.

This counter weight 32 is used when setting the test piece 12.
The lid plate 16 can be opened easily.

Further, a telescopic bellows 35 is interposed between the lid plate 16 and the flange 19b of the intermediate rod 19 to maintain airtightness inside the test chamber 2. Here, if the spring constant of the bellows 35 is K (kg/+111) and its elongation is δ (a+i), as the bellows 35 extends, a load error of K・δ (kg) will occur in this test device. It turns out.

According to this embodiment, the correction spring 36 is used to correct this load error.

This correction spring 36 has one end connected to the horizontal lever 20.
The other end is connected to the lifting flange 5 via a support piece 38.

At this time, the spring constant of the correction spring 36 is K/R (kg
/am), and as shown in the figure, the distance between the intermediate rod 19 and the support member 21 is set to X, and the distance between the support member 21 and the wire 37 is set to Rx.

Next, the operation of this embodiment will be explained.

After setting the test piece 12 inside the test chamber 2, remove the lid plate 1.
6 is bolted to the upper end of the test chamber 2.

At this time, due to the action of the counter weight 32, the cover plate 16
can be opened and closed easily. After setting the test piece 12, set the creep test weight 23,
The test chamber 2 is raised and lowered by driving the motor 10 until the horizontal lever 20 becomes horizontal. At this time, balance weight 29
Zero balance can be achieved by by this,
The creep test is started, and the test piece 12 is subjected to an atmosphere from the heating furnace 3 and a creep load from the creep test weight 23 .

By the way, in this type of creep test device, the test piece 12
In order to apply a vertical load to the horizontal lever 20,
is always maintained horizontally. In other words, when performing a creep test, the test piece 12 gradually stretches until it finally breaks, but as the test piece 12 stretches, the horizontal lever 20 follows suit, and this inclination When detected by the photosensor 28, the motor 10 is driven,
The test chamber 2 is automatically lowered according to the amount of elongation of the test piece 12, and the horizontal lever 20 is always maintained in a horizontal state.

When this test chamber 2 is lowered, the bellows 3
5 force also elongates, and when this elongates, as mentioned above, if the spring constant of the bellows 35 is K (J/mm) and the elongation is δ (+1111), the load error of K・δ (kg) becomes arise. When this load error K・δ (kg) occurs, even if the creep load by the creep test mold N, 23 continues to be applied, the creep load applied to the test piece 12 will decrease by that amount, and the accuracy will be reduced. It becomes impossible to apply a load to the

According to this embodiment, as described above, since the correction spring 36 is provided, the correction spring 36 is extended at the same time as the bellows 35 is extended, and thus the above-mentioned load error K.δ
(kg) is automatically corrected.

The spring constant of the correction spring 36 is K/R (kg/as
) and the elongation is δ(l-), the correction spring 36
Correction r due to elongation: 1 weight is /R・δ (kg), and as shown in the figure, the intermediate rod 19 and the support member 21
The distance between the support member 21 and the wire 37 is R.
x, so considering the moment force around the support member 21, K-δ-x- becomes /Rφδ・Rx −(1), so the load is 5,7K・δ and the correction load is /R・δ. This results in an accurate correction of the load error.

As described above, according to this embodiment, an excellent effect can be obtained in that accurate load error correction can be performed with an extremely simple configuration that only requires the correction spring 36.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, a correction spring is provided, and one end of the correction spring is connected to the horizontal lever, and the other end of this spring is connected to the test chamber. Even if load errors occur due to expansion and contraction,
Since this is automatically corrected, the leap load can always be applied accurately. Further, since only a correction spring is provided, manufacturing is extremely simple, and effects such as being able to be made at low cost can be obtained.

[Brief explanation of the drawing]

The drawing is a sectional view showing an embodiment of the creep test device according to the present invention. 1... Frame, 2... Test tank, 3... Heating furnace,
5... Lifting flange, 12... Test piece, 17...
Pull rod, 19... Intermediate rod, 20... Water W lever, 21... Support member, 23... Weight for creep test, 36... Spring for correction.

Claims (1)

[Claims] A frame, a test tank supported by the frame so as to be able to rise and fall, a pull rod that can move up and down to apply a tensile force to the test specimen held in the test tank, and an intervening device between the pull rod and the test tank. A telescopic bellows that maintains the airtightness in the test chamber is swingably supported by the frame via a support member, and the pull rod is connected to one end with a pin, and the other end is a bellows for creep testing. In a creep test device comprising a horizontal lever on which a weight is suspended, a correction spring is provided to correct the load error caused by the expansion and contraction of the bellows, and one end of the correction spring is attached to the horizontal lever. A creep test device characterized in that the other end of the correction spring is connected to the test tank.