JP3608294B2 - Material testing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a material testing machine that measures the strength against the internal pressure of a tubular test piece by applying pressure to the inside of the tubular test piece.
[0002]
[Prior art]
There is known a material testing machine that applies pressure to the inside of a tubular test piece and measures the strength of the tubular test piece against the internal pressure. As shown in FIG. 5, the material testing machine includes a lower jig 41 and an upper jig 42 having pipe lines 41d and 42d for connecting upper and lower ends of a tubular test piece T having a pipe line to the pipe line. The tubular test piece T is filled with pressure oil, and the pressure of the pressure oil is further increased to load the tubular test piece T with internal pressure, thereby measuring the strength of the test piece T against the internal pressure. It is.
[0003]
In such a material testing machine, when supplying the pressure oil to the tubular test piece T, the pressure oil is gradually supplied from the pressure oil introduction port of the lower jig 41 into the pipe line, and the pressure oil of the upper jig 42 is supplied. When the pressure oil reaches the lead-out port, the pressure oil lead-out port is sealed, and the pressure oil is filled in the pipe line of the test piece T. At this time, since the pressure oil is supplied from the lower side to the upper side of the tubular test piece T, the gas in the pipes 41d and 42d in the tubular test piece T, the lower jig 41 and the upper jig 42 is guided by the pressure oil. It is led out of the pipeline from the outlet.
[0004]
[Problems to be solved by the invention]
However, when pressure oil is supplied into the tubular test piece as described above, if a portion having a shape as shown in FIG. Even if pressure oil is supplied from the side, the gas in the pipe line 42d cannot be completely eliminated, and an air reservoir B as shown in FIG. 6 is formed. When such an air reservoir B is formed, the air reservoir B is compressed even if the pressure of the pressure oil in the pipe is increased. A delay occurs, and the pressure in the test piece T cannot be instantaneously increased.
[0005]
An object of the present invention is to provide a material testing machine capable of instantaneously increasing the pressure inside a tubular test piece.
[0006]
[Means for Solving the Problems]
Referring to FIG. 1 showing an embodiment, the invention of claim 1 holds the upper and lower ends of a tubular test piece T having a pipe line therein and communicates with the pipe line of the tubular test piece T. A negative pressure is applied to the inside of the tubular test piece T connected to the valve 26 and the valve 26 connected to the pipe 12d of the upper jig 12 and the upper and lower jigs 11 and 12 having the pipes 11d and 12d. The negative pressure means 35 and the pressure medium supply means 30 connected to the pipe line 11d of the lower jig 11 for supplying the pressure medium to the inside of the tubular test piece T are provided . The negative pressure means 35 and the pressure medium supply means 30 are provided. by both driving the door, while the action of negative pressure in the interior of the tubular specimen T, to supply pressure medium to the interior of the tubular specimen T, then the pressure medium supply means after stopping the action of the negative pressure 30 by acting high pressure pressure medium from the tube By performing the test in a state where the air accumulation does not remain in the test piece T, and the upper jig 12 to achieve the above object.
[0007]
According to the invention of claim 1, the tubular test piece T is gripped by the upper and lower jigs 11 and 12, the valve 26 is opened, and negative pressure is applied from the pipe line 12 d of the upper jig 12 by the negative pressure means 35. A pressure medium is supplied from the pipe line 11 d of the lower jig 11 by the pressure medium supply means 30. When a predetermined amount of pressure medium is supplied, the valve is closed and the pressure medium is supplied into the tubular test piece T by the pressure medium supply means 30 to increase the internal pressure of the tubular test piece T. The pressure in the tubular test piece T is measured by the pressure measuring means 21 and 23. Then, the pressure is increased until the tubular test piece T breaks, and the strength of the test piece T with respect to the internal pressure is measured.
[0008]
In the section of the means for solving the above-described problems for explaining the configuration of the present invention, the drawings of the embodiments of the invention are used for easy understanding of the present invention. It is not limited.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing the configuration of a material testing machine according to the present invention. As shown in FIG. 1, the tester main body 10 includes a load frame LF. The load frame LF is configured such that a yoke 10a is horizontally mounted on the upper ends of a pair of supports 10k and 10m provided upright on a base 10d, and a crosshead 10b is attached to the supports 10k and 10m so as to be vertically movable. A hydraulic actuator 10e for load is installed on the base 10d, and is tubular between the lower jig 11 attached to the movable part of the hydraulic actuator 10e and the upper jig 12 attached to the crosshead 10b via the load cell 13. A test piece (hereinafter simply referred to as a test piece) T is gripped. A cover 10f is provided around the test piece T.
[0010]
2 and 3 are cross-sectional views showing detailed configurations of the lower jig 11 and the upper jig 12. As shown in FIG. 1 and FIG. 2, the lower jig 11 includes a main body 11a, an adapter 11b for attaching the test piece T, an attachment portion 11c for attaching the adapter 11b to the main body, and a pressure oil in the pipe line 11d inside the main body. And a pressure oil supply part 11e for supplying. The test piece T is attached to the adapter 11b by screw joints 20a, 20b, and 20c. An internal thread portion 11f is formed inside the attachment portion 11c, and an external thread portion 11g is formed above the main body 11a. The adapter 11b is placed on the upper portion of the main body 11a, and the attachment portion 11c is attached from the upper side of the adapter 11b. The test piece T is fixed to the main body 11a by fastening the female screw part 11f of the attachment part 11c and the male screw part 11g of the main body 11a. A hydraulic pressure source 30 is connected to the pressure oil supply unit 11e through a valve 34. The hydraulic source 30 includes a hydraulic pump 31, a tank 32, and a relief valve 33. Moreover, the pressure detector 21 which measures the internal pressure of the test piece T is attached to the main body 11a. The pressure detector 21 is connected to a calculation unit 22 that measures the internal pressure strength of the test piece T based on the detected pressure.
[0011]
As shown in FIGS. 1 and 3, the upper jig 12 has a negative pressure applied to the main body 12a, an adapter 12b for attaching the test piece T, an attachment portion 12c for attaching the adapter 12b to the main body, and a pipe line 12d inside the main body. And a negative pressure acting part 12e for acting. The test piece T is attached to the adapter 12b by screw joints 20d, 20e, and 20f. A female screw portion 12f is formed inside the mounting portion 12c, and a male screw portion 12g is formed at the lower portion of the main body 12a. The test piece T is fixed to the main body 12a by fastening the female screw portion 12f of the mounting portion 12c and the male screw portion 12g of the main body 12a. A vacuum pump 35, which is a negative pressure source, is connected to the negative pressure acting portion 12e through a valve 26. Further, a pressure detector 23 for measuring the internal pressure of the test piece T is attached to the main body 12a. Similar to the pressure detector 21, the pressure detector 23 is connected to a calculation unit 22 that measures the internal pressure strength of the test piece T based on the detected pressure.
[0012]
4 is a diagram showing the configuration of the valve 26, and is a view taken in the direction of arrow A in FIG. As shown in FIG. 4, the valve 26 includes a threaded portion 26a, a first seal portion 26b, a second seal portion 26c, a head portion 26d, an oil sump 26e, and an outlet portion 26f. A liquid confirmation tube 27 made of a transparent member is connected to the outlet portion 26f. The valve 26 is opened and closed by rotating the head portion 26d with a jig such as a hexagon wrench and a spanner, and pressure oil flows out from the oil sump 26e toward the outlet portion 26f according to the degree of opening and closing. At this time, leakage of pressurized oil from the screw portion 26a is prevented by the first seal portion 26b. Further, when the screw portion 26a is completely tightened, the second seal portion 26c prevents pressure oil from leaking from the oil sump 26e toward the outlet portion 26f.
[0013]
Next, the operation of the present invention will be described.
First, the test piece T is attached to the adapters 11b and 12b by the threaded joints 20a to 20f, and the adapters 11b and 12b are attached to the main bodies 11a and 12a by the attachment portions 11c and 12c. The test piece T is fixed to the tool 12, and the periphery of the test piece T is surrounded by a cover 10f. Thereafter, the hydraulic actuator 10 e is driven to apply a tensile load to the test piece T, and the tensile load is detected by the load cell 13. After the predetermined tensile load is applied to the test piece T, the drive of the hydraulic actuator 10e is stopped.
[0014]
After that, the valve 26 is opened and the vacuum pump 35 is driven to suck the gas in the test piece T from the negative pressure acting portion 12e of the upper jig 12 and apply a negative pressure (for example, 50 torr) to the inside of the test piece T. Make it work. At this time, the first seal portion 26b prevents the outside air from entering from the screw portion 26a. Further, the hydraulic pump 31 is driven and the valve 34 is slightly opened to gradually supply the pressure oil into the test piece T from the pressure oil supply portion 11e of the lower jig 11 in a low pressure state. The pressure oil supplied from the pressure oil supply unit 11e is supplied to the valve 26 through the pipe line 11d in the lower jig 11, the test piece T, and the pipe line 12d in the upper jig 12d. In the valve 26, it is supplied from the oil reservoir 26e to the liquid confirmation pipe 27 through the outlet 26f. When it is confirmed that the pressure oil is supplied to the liquid confirmation pipe 27, the valve 26 is closed and the vacuum pump 35 is stopped. In this state, gas is removed from the pipe line 11d in the lower jig 11, the test piece T, and the pipe line 12d in the upper jig 12d, and each pipe line is filled with pressure oil. Yes.
[0015]
In this state, high pressure oil is supplied into the test piece T from the hydraulic pump 31 to increase the internal pressure of the test piece T, and the internal pressure of the test piece T is detected by the pressure detectors 22 and 23. Furthermore, pressure oil is supplied into the test piece T to increase the internal pressure of the test piece T, and the test is terminated when the test piece T is broken by the internal pressure of the pressure oil. In addition, since the circumference | surroundings of the test piece T are surrounded by the cover 10f, even if the test piece T destroys, pressure oil will not scatter. Further, the pressure oil scattered in the cover 10 f is taken out from the outflow hole 11 h formed in the attachment portion 11 c of the lower jig 11.
[0016]
As described above, in the present embodiment, since the pressurized oil is supplied into the test piece T while applying a negative pressure, the pipe line 11d, the test piece T, and the upper jig 12d in the lower jig 11 are provided. No air pocket is formed in the pipe line 12d. Therefore, even if pressure oil is supplied, the pressure in the test piece T can be instantaneously increased without causing a delay in the propagation of pressure.
[0017]
In the above embodiment, the tensile strength is applied to the test piece T, and then the strength against the internal pressure of the test piece T is measured. However, the internal pressure of the test piece T is not particularly applied to the test piece T. The present invention can also be applied to the case where the strength is measured or the test is performed while applying a repeated load.
[0018]
In correspondence between the above embodiment and the claims, the vacuum pump 35 is a negative pressure means, the hydraulic source 30 is a pressure medium supply means, the pressure measuring devices 21 and 23 are pressure measuring means, and the hydraulic actuator 10e is a load load. Each means is configured.
[0019]
【The invention's effect】
As described in detail above, according to the present invention, by driving both the negative pressure means and the pressure medium supply means , the pressure medium is supplied into the tubular test piece while acting the negative pressure. Air does not remain in the pipes in the tubular test piece and the upper and lower jigs. Therefore, even if the pressure medium is supplied, the pressure in the tubular test piece can be instantaneously increased without causing a delay in the pressure propagation, and the test can be performed with high accuracy.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a material testing machine according to an embodiment of the present invention. FIG. 2 is a sectional view showing a configuration of a lower jig. FIG. 3 is a sectional view showing a configuration of an upper jig. FIG. 5 is a cross-sectional view showing the structure of a valve. FIG. 5 is a view showing the structure of a conventional material testing machine. FIG. 6 is a view showing a state where an air pocket is formed.
10 Material testing machine 10k, 10m Post 10e Hydraulic actuator 11 Lower jig 12 Upper jig 21, 23 Pressure measuring device 26 Valve

Claims (1)

An upper and lower jig having a pipe line communicating with the pipe line of the tubular test piece, while holding the upper and lower ends of the tubular test piece having a pipe line inside,
A valve connected to the pipe line of the upper jig;
Negative pressure means connected to the valve for applying a negative pressure to the inside of the tubular test piece;
The supplying pressure medium to the interior of the tubular test piece, and a connected pressure medium supply means to the conduit of the lower jig,
Wherein the both by driving and said pressure medium supply means negative pressure means, while the action of negative pressure inside the tubular test piece, and supplies the pressure medium in the interior of the tubular test piece, then, the valve The test is performed in a state where no air pool remains in the tubular test piece and the upper jig by applying a high pressure medium from the pressure medium supply means after closing the negative pressure and stopping the negative pressure action. A material testing machine featuring.

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