JPH0260252B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a method for continuously introducing test pieces into a fracture toughness testing section in each temperature range of low temperature, extremely low temperature, and ultra-low temperature. Split allows continuous fracture toughness testing of
Hopkinson Bar method (hereinafter referred to as SHB method)
Concerning continuous dynamic fracture toughness testing equipment.

[Conventional technology]

The conventional dynamic fracture toughness testing device using the SHB method is composed of an input rod, an output rod, a striker, and a firing section of the striker, and when the striker is dropped and collides with the input rod, the input rod is Compressive stress waves are generated in the rod,
This stress wave propagates through the input rod as an incident stress,
The transmitted wave is propagated into the output rod through a flanged cylindrical test piece held in the output rod, and at this time, the above-mentioned physical phenomenon is detected by strain gauges attached to the input rod and output rod, respectively. The dynamic load (stress) and elongation applied to the test piece are measured as a function of time.

[Problem that the invention seeks to solve]

However, according to the above-mentioned conventional apparatus, when replacing a tested specimen with a new test piece in the test section inside the container each time a test is performed, the container must be opened. The refrigerant sealed in the body is dissipated, resulting in a large amount of loss, which is not only uneconomical. This method has problems such as being time-consuming and inefficient in bringing the inside of the container to a constant temperature range.

[Means for solving problems]

In order to solve the above-mentioned problems of the conventional device, the present invention has a striker inside the heat-insulating structure body filled with refrigerant, and a striker passage piping that can integrally pull up the input rod attached at the bottom. A test section formed by this and an output rod fixed coaxially to the lower part is hung inside, and an inner cylinder is hung inside to surround the upper part of the test section, and the inner cylinder has a A test specimen storage cylinder capable of storing a plurality of new test specimens from the top; a test specimen exchange rod having a guide lever attached to the bottom and rotatably supported by penetrating the upper flange of the inner cylinder; are hung inside each other in parallel, and the guide plate at the lower end of the inner cylinder receives and fits one test piece from the test piece storage cylinder, and is pressed to the test piece fixing part of the output rod by the guide lever. The output rod is provided with a groove for transferring and a notch that is cut out in the direction of rotation of the guide lever so that the tested specimen can be dropped into the container. A test piece lifting rod is inserted through the longitudinal groove provided and has one end protruding outside the vessel.This allows the input rod to be pulled up and held at a predetermined height together with the striker passage piping, and then the test piece lifting rod can be pulled up. Operate the test piece to drop it into the container, then rotate the test piece exchange rod to fit and fix a new test piece into the test piece fixing part of the output rod through the groove, and repeat this operation. The structure is such that test pieces can be continuously inserted into the test piece fixing part.

〔Example〕

As shown in Figures 1 to 5, the vessel 1
In this case, an outer tank 2 with a large diameter, an intermediate tank 3 with an intermediate diameter, and an inner tank 4 with a small diameter are fastened with a plurality of bolts 5 with their respective flanges 2a, 3a, and 4a overlapped. The tanks 2, 3, and 4 are formed in a hermetically sealed three-tank structure by
b, 4b and the bottom walls 2c, 3c, 4c are held apart from each other, and a heat insulating material 6 is filled between the outer tank 2 and the intermediate tank 3. A refrigerant 7, 7' such as liquid nitrogen or liquid helium is stored between the refrigerant 3 and the inner tank 4 and within the inner tank 4.

The heat insulating material 6 is formed by wrapping a metal thin film or the like in multiple layers between the outer tank 2 and the intermediate tank 3, then sealing the tank and evacuating the tank.

Further, bolts 10 are attached to the inner tank 4 with the flange 9a superimposed on the flange 4a.
An inner cylinder 9, which is fixed with
In a position eccentric to one side from the center, a striker passage pipe 11 with a striker 12 installed therein and an input rod 13 fitted and supported at its lower end and a striker passage pipe 11 located below the striker passage pipe 11 and coaxially arranged. A test section 15 formed by an output rod 14 that is fixed upright from the bottom wall 4c of the inner tank 4 is installed vertically inside the test section 15, and approximately the upper half of this test section 15 is surrounded by the inner cylinder 9. has been done.

Here, the striker passage piping 11 of the test section 15 passes through the flange 9a of the inner cylinder 9 and is inserted into a cylindrical body 16 that is slidably suspended in the vertical direction.
By interposing a spacer 17 therein, the input rod 13 is penetratingly supported in a spaced state, and is thereby formed into a unit so that it can be removed together with the input rod 13, and the flange 9a of the inner cylinder 9
As shown in FIG. 6, a groove 1 having a substantially V-shaped cross section is provided between the flange 18, which is fixed on the top and surrounding the cylindrical body 16, and the flange 9a.
9 is provided around the periphery, and a packing 20 is fitted thereto, so that the inner tank 4 is hermetically sealed.

Further, the striker passage piping 11 ends approximately at the center of the input rod 13, and a bellows seal 21 is provided between the lower end of the piping 11 and the input rod 13.
Furthermore, as a stopper when the input rod 13 falls, a spring 23 supported by an auxiliary plate 22 fixed near the lower end of the inner cylinder 9 is connected to the flange 8 of the input rod 13. The rod 13 is inserted into a hole 22a formed in the auxiliary plate 22 so as to be vertically slidable.

Further, a gas relief port 24 equipped with a check valve (not shown) is provided on one side of the upper portion of the cylindrical body 16, and communicates with the gas relief port 24 near the lower end of the striker passage piping 11. A gas vent hole 11a is provided so that the gas supplied to the piping 11 can be discharged so that the striker 12 can be moved under pressure as described in detail later.

Further, inside the inner tank 4, at the center of the inner cylinder 9, a test specimen exchange rod 25 having a guide lever 25b attached to the lower part is connected to the flange 9a of the inner cylinder 9 and the lower end of the inner cylinder 9. Guide plate 2 fixed to
The upper end 25a is fitted and supported by the upper and lower ends of the container 6 so that it can be rotated around the axis and can be rotated from the outside of the container 1. At an eccentric position of the inner cylinder 9, there is a test piece storage cylinder 27 having a sealing ring 27a at the upper end opening.
and the above-mentioned auxiliary plate 22 in a state where it is penetrated and fixed,
A hanging rod is installed in parallel with the test piece exchange rod 25 mentioned above.

Since the test piece 28 used here has a cylindrical shape with a flange 28a on the outer periphery of the upper end, the test piece storage tube 27 is constructed by vertically stacking the test pieces 28 of the above shape as shown in FIG. It is formed so that a plurality of specimens can be accommodated in the same state, and its lower end extends from the upper surface of the guide plate 26 to at least the collar 28a of the test specimen 28.
terminating at a position with a spacing slightly greater than the thickness of the material.

The output rod 14 is a cylindrical member 14 having an inner diameter such that the test piece 28 can be fitted therein and fixed by the collar 28a engaging with the upper end surface.
a, and at its upper end, a short cylinder 29 having an inner diameter corresponding to the outer diameter of the collar 28a of the test piece 28 is coaxial with the cylindrical member 14a and fixed to the guide plate 26. Particularly, a test piece fixing part 30 is formed, and the recess 28b of the test piece 28' loaded in the test piece fixing part 30 is
The input rod 13 is inserted through the test piece fixing part 30.

Furthermore, a substantially arc-shaped groove 31 is formed in the guide plate 26 through the guide plate 26, as shown in FIG. There is.

The groove portion 31 is formed with a width that allows the main body portion of the test piece 28 to be slidably fitted therein, and a plurality of test pieces 28 are stored in the test piece storage tube 27 in a stacked state. As a result, only the lowermost test piece 28' is engaged and held as shown in FIGS. 1 and 2, and the test piece exchange rod 2
5 in the clockwise direction in FIG. 4, the guide lever 25b is also rotated in the same direction, so that the guide lever 25b fixes only the lowermost test piece 28' along the groove 31. The fixed part 30 is pressed and transferred to the fixed part 30.
It is designed so that it can be inserted into the

Further, a longitudinal groove 14c is provided on one side of the peripheral wall 14b of the output rod 14, and a test piece lifter is slidably inserted into the longitudinal groove 14c with one end protruding outward from the upper part of the vessel body 1. A rod 32 is provided, and by pulling up the lifting rod 32, the tested specimen 28 held in the fixing part 30 is lifted.
is provided so that it can be lifted upward and removed from the fixing part 30.

Here, the test piece lifting rod 32 is a lifting rod 3 installed vertically inside the output rod 14.
2a and a lifting rod 32b which is vertically installed in the inner tank 4 and whose upper end protrudes to the outside of the container body 1. Both lower ends of the lifting rod 32b are inserted into the vertical groove 14c and are inserted into the horizontal rod 32c. A plate-shaped test piece lifting plate 32d is attached to the upper end of the lifting rod 32a, and as shown in FIG. The bottom wall 28c of the test piece 28 is dropped and held onto the lifting plate 32d, and the bottom wall 28c is lifted together with the test piece 28 by a lifting operation.

Furthermore, one half of the guide plate 26 has a notch 33.
is provided through the notch 3 as shown in FIG.
3, the tested specimen 28 can be dropped into the inner tank 4.

Further, a cylindrical body 1 that unitizes the input rod 13 is provided.
6 is formed into a stopper structure at the flange 18, and is thereby stopped at a desired position.

Furthermore, as clearly shown in FIG. 3, a refrigerant transfer port 34 and a gas refrigerant recovery port 35 are provided in the upper part of the vessel 1, respectively.

FIG. 7 is a schematic diagram of the entire device of the present invention, and in the figure, 36 is a strain gauge attached to the input rod 13;
7 is a strain gauge attached to the output rod 14, 38 is a vacuum line, 39 is a gas line, 40 is a gas source, 41
indicate electromagnets.

With the above configuration, when performing a dynamic fracture toughness test using this, the sealing plug 27a is removed, and a desired number of test pieces 28 are piled up,
It is stored in the storage cylinder 27, and the opening is closed with a sealing plug 27a.
Keep it tightly closed.

In this state, the lowermost test piece 28' is
It is fitted into one end of the groove 31 as shown in FIGS. 2, 2, and 4, respectively.

Next, while the unitized striker passage piping 11 and input rod 13 are pulled up to the position shown in FIG. 2 and held there, the test piece exchange rod 25 is rotated clockwise in FIG. Since the guide lever 25b also rotates in the same direction, the guide lever 25b presses and transfers the lowermost test piece 28' along the groove 31.
Insert the test piece into the test piece fixing part 30 at the upper end of the output rod 14.

The test piece exchange rod 25 further rotates in the same direction, and the guide lever 25b moves into the storage tube 27.
Stop at a position close to .

When the lowermost test piece 28' is transferred in this way, a plurality of test pieces 28 in a stacked state...
is lowered by one step (one test piece), and the second step test piece 28 is engaged and held in the groove 31, and is prepared for the next transfer.

Next, the striker passage piping 11 and input rod 13, which have been pulled up to the position shown in FIG. 2, are pushed down and the lower end of the input rod 13 is inserted into the recess 28b of the test piece 28 as shown in FIG. The preparation for the test is now complete.

In this state, operate the vacuum (not shown),
The striker 12 is pulled up to the top by the vacuum line 38, the electromagnet 41 is energized, and the striker 1
2 is suctioned and held at the top.

Next, the excitation of the electromagnet 41 is released, and gas at a constant pressure is supplied from the gas line 39 to the upper part of the striker passage piping 11, and the striker 12 is forced to fall by the gas pressure.

Due to the fall of the striker 12, a load is applied to the input rod 13, and the bottom wall 28c of the recess 28b in the test piece 28 is destroyed, but this change in state is detected and recorded by the strain gauges 36 and 37, and the test is completed. The fracture toughness value of the piece 28 can be tested.

Further, the gas that forces the striker 12 to fall is discharged to the outside from the gas release port 24 through the gas release hole 11a provided at the lower end of the striker passage piping 11.

After completing the first test in this way,
With the input rod 13 pulled up and held together with the striker passage piping 11 as shown in FIG.
In this state, lift the specimen from the specimen exchange rod 25.
When rotated in the same direction as described above, the test piece 2 fitted in the groove 31 at the bottom of the storage tube 27
8 is pressed by the guide lever 25b and the groove 3
1 to the fixing section 30, but at this point the tested specimen 28 is removed from the fixing section 30 by the lifting rod 32 and is held in that position, so a new test specimen is transferred. 28, and by further rotating the exchange rod 25, a new test piece 28 is introduced into the fixing part 30.

When the exchange rod 25 is further rotated in the same direction, the tested specimen 28 on the guide plate 26
is pressed by the guide lever 25b, so that it falls from the notch 33 of the guide plate 26 to the lower part of the inner tank 4.

By repeating the same operations as described above, a plurality of test pieces 28... can be tested in succession.

〔Effect of the invention〕

As explained above, the continuous dynamic fracture toughness testing device according to the present invention is configured and operates, so that the striker passage piping 11 and the input rod 13
By repeating the vertical movement of the test piece lifting rod 32 and the rotational movement of the test piece exchange rod 25, the desired number of test pieces 28 stored in advance in the test piece storage tube 27 in a piled state is removed. . . . can be continuously supplied one by one and dynamic fracture toughness tests can be performed sequentially, and the tested test piece 28 can be replaced with a new test piece 28 while the container body 1 is sealed. , and can be carried out in a predetermined temperature range, which eliminates the wasted time of having to wait until the temperature range is created, making the test using the SHB method more efficient. Furthermore, by selectively using the refrigerant in the container 1, such as liquefied chlorofluorocarbon, alcohol, liquefied nitrogen, liquefied helium, etc., low temperature,
Continuous fracture toughness testing in cryogenic and ultra-low temperature regions becomes possible.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view showing the continuous dynamic fracture toughness testing device according to the present invention in a test state, Fig. 2 is a longitudinal cross-sectional side view showing the test piece exchange state of the device, and Fig. 3 is the same device. , FIG. 4 and FIG. 5 are cross-sectional views along the - line and - line in FIG. 1, FIG. 6 is an enlarged vertical sectional side view of section A in FIG. 1, and FIG. It is an overall schematic diagram. 1... Container body, 9... Inner cylinder, 11... Striker passage piping, 12... Striker, 13... Input rod, 14... Output rod, 14c... Longitudinal groove, 15
...Test section, 16... Cylindrical body, 25... Test piece exchange rod, 25b... Guide lever, 26... Guide plate, 27... Test piece storage cylinder, 28... Test piece, 30... Test piece Fixed part, 31...Groove part, 32
... Test piece lifting rod, 33 ... Notch.

Claims (1)

[Claims] 1. A heat-insulating structure housing a refrigerant is equipped with a striker passage piping that can integrally pull up an input rod attached to the lower part, and a striker passage piping that is fixed coaxially to the lower part. The test section formed by the output rod is hung inside, and
An inner cylinder is hung down to surround the upper part of the test section, and the inner cylinder is equipped with a test specimen storage cylinder that can accommodate a plurality of new test specimens from the top, and a guide lever at the bottom. , and a test piece exchange rod that is rotatably supported by penetrating the upper flange of the inner cylinder are hung down in parallel with each other, and the guide plate at the lower end of the inner cylinder receives the test piece from the test piece storage cylinder. There is a groove in which the test piece is fitted and pressed to the test specimen fixing part of the output rod by the guide lever, and a groove in the rotating direction of the guide lever so that the tested test specimen can be dropped into the chamber. The output rod is provided with a test specimen lifting rod that is inserted through a longitudinal groove provided in the output rod and has one end protruding outside the vessel body. Continuous dynamic fracture toughness testing equipment. 2. Claims in which the striker passage piping of the testing section and the input rod are integrated into a unit that can be taken out from a cylindrical body that is inserted through the top wall of the vessel so that it can slide in the vertical direction. 2. The continuous dynamic fracture toughness test device according to item 1.