Adjustable diaphragm capsule pressure-bearing fatigue performance test device and method
Technical Field
The invention relates to a device for testing the strength characteristic of a material and a using method thereof, in particular to an adjustable bellows pressure-bearing fatigue performance testing device and method, which are used for testing the pressure-bearing fatigue performance of a bellows by applying a repetitive force.
Background
The diaphragm capsule is an element formed by welding a plurality of diaphragms, has excellent compression performance in the axial direction, can adapt to low-temperature, high-temperature or high-pressure environments, is used for replacing a spring or matching the spring to provide elasticity, is mainly used in rotary machinery, and is very critical in a pressure-bearing fatigue performance test of the diaphragm capsule under special working conditions because of higher requirements on the working conditions of the rotary machinery in some special fields such as aerospace, ship weapons and the like.
At present, the pressure-bearing fatigue performance test of the diaphragm capsule is to introduce air into a cavity for pressurization, exhaust and reduce pressure after the diaphragm capsule is pressurized to the maximum value, and the pressure-bearing fatigue performance of the diaphragm capsule is tested through repeated tests. Chinese patent CN107328671B proposes a test system for testing fatigue performance of a diaphragm capsule under alternating pressure, which can adjust the lowest pressure borne by the diaphragm capsule, and such a test can reflect the fatigue performance of the diaphragm capsule under alternating pressure to a certain extent, but cannot reflect the pressure-bearing fatigue performance of the diaphragm capsule under high and low temperatures, and cannot test the pressure-bearing fatigue performance of the diaphragm capsule under different initial compression amounts.
Disclosure of Invention
The invention aims to solve the problem that the pressure-bearing fatigue performance of a diaphragm capsule can not be tested at high and low temperatures and under different initial compression amounts in the prior art, and provides an adjustable diaphragm capsule pressure-bearing fatigue performance testing device and method.
The invention provides an adjustable diaphragm capsule pressure-bearing fatigue performance test device, which is characterized in that: the diaphragm capsule sealing device comprises a lower flange, a diaphragm capsule connecting block, a static sealing ring, an upper flange, a connecting shaft and a connecting disc; the lower end of the lower flange is used for being connected with a lower connector of an external tensile testing machine, the upper end of the lower flange is provided with a central cavity, and the lower flange is also provided with an air hole communicated with the central cavity; the upper flange is arranged above the lower flange, and a static sealing ring is arranged between the lower flange and the upper flange; the bellows connecting block is positioned in the central cavity; the diaphragm capsule to be tested is positioned in the central cavity and is fixedly arranged between the upper flange and the diaphragm capsule connecting block; one end of the connecting shaft penetrates through the upper flange and the to-be-detected diaphragm capsule in sequence and then is connected with the diaphragm capsule connecting block, and the other end of the connecting shaft is fixedly connected with the connecting disc; an annular boss is arranged in the middle of the upper flange, the connecting shaft penetrates through the middle of the annular boss, and a positioning hole which is perpendicular to the connecting shaft and is provided with threads is arranged on the annular boss; the connecting disc is used for being connected with an upper joint of the tensile testing machine.
Furthermore, axial keyway type through holes are evenly distributed on the circumference of the connecting disc.
Furthermore, the positioning holes are uniformly distributed on the side wall of the annular boss in the circumferential direction.
Meanwhile, the invention also provides a method for testing the pressure-bearing fatigue performance of the adjustable diaphragm box, which is characterized in that the device for testing the pressure-bearing fatigue performance of the adjustable diaphragm box comprises the following steps:
1) fixedly connecting a diaphragm capsule to be tested between a diaphragm capsule connecting block and an upper flange, placing a static sealing ring between a lower flange and an upper flange, connecting and fixing the lower flange and the upper flange, sequentially passing a connecting shaft through the upper flange, connecting the diaphragm capsule to be tested with the diaphragm capsule connecting block, screwing a set screw from a side wall positioning hole of the upper flange, connecting and fixing the connecting shaft and a connecting disc, fixing the connecting shaft and the upper flange through a key groove type through hole centering device of the connecting disc, connecting and fixing the connecting shaft and the connecting disc, then connecting the connecting disc and an upper joint of a tensile testing machine, connecting the lower flange and a lower joint of the tensile testing machine, reading the indication of the tensile testing machine at the moment as a zero point of the compression amount of the diaphragm capsule, and then detaching the set screw at;
2) controlling the position of an upper joint of the tensile testing machine in the vertical direction, and setting the initial compression amount of the diaphragm capsule to be tested;
3) the test conditions are controlled by adjusting or replacing the pressure, the pressurizing medium and the ambient temperature in the central cavity;
4) according to the preset requirements, carrying out a corresponding capsule pressure-bearing fatigue performance test to obtain the pressure-bearing fatigue performance of the capsule to be tested under various environments such as preset pressure, temperature, medium and the like;
5) and (3) replacing the diaphragm capsule to be tested for many times according to preset conditions, repeating the steps 1) to 4) and changing the test conditions in the step 3), so that the bearing fatigue performance of the diaphragm capsule to be tested under different environmental test conditions can be obtained.
Compared with the prior art, the invention has the beneficial effects that:
(1) the invention can be zeroed through the positioning hole on the side wall of the upper flange, and the initial compression amount of the diaphragm capsule to be tested can be set by controlling the position of the upper joint of the tensile testing machine in the vertical direction, thereby improving the compression precision of the test.
(2) The invention adjusts the test environment pressure through the air holes on the side wall of the lower flange, and connects the air holes with different pipelines, so that different test environment pressures can be formed, including a diaphragm capsule fatigue performance test under normal pressure, a diaphragm capsule fatigue performance test under pressurization and a vacuum diaphragm capsule fatigue performance test.
(3) The invention can meet different test environment temperatures, and the static sealing ring between the upper flange and the lower flange can be replaced by proper materials according to the test environment temperatures.
(4) The central cavity can be filled with various media such as liquid hydrogen, liquid oxygen, methane, oxygen-enriched gas, dinitrogen tetroxide, hydrazine media, water, nitrogen, air, kerosene, fuel oil and the like through the air holes on the side wall of the lower flange, and the central cavity has a wide application range.
Drawings
FIG. 1 is a schematic cross-sectional view of an embodiment of the present invention;
fig. 2 is a schematic illustration of an explosive structure according to an embodiment of the present invention.
The reference numerals are explained below: 1-lower flange, 2-capsule connecting block, 3-static sealing ring, 4-upper flange, 5-connecting shaft, 6-connecting disc, 7-central chamber, 8-capsule to be measured, 9-annular boss and 10-positioning hole.
Detailed Description
The invention will be further described with reference to the drawings and exemplary embodiments.
Referring to fig. 1 and 2, the invention provides an adjustable capsule pressure-bearing fatigue performance test device, which comprises a lower flange 1, a capsule connecting block 2, a static sealing ring 3, an upper flange 4, a connecting shaft 5 and a connecting disc 6; the lower end of the lower flange 1 is used for being connected with a lower connector of an external tensile testing machine, the upper end of the lower flange is provided with a central chamber 7, and the lower flange 1 is also provided with air holes communicated with the central chamber 7 and the outside; the upper flange 4 is arranged above the lower flange 1 through bolts, and a static sealing ring 3 is arranged between the lower flange 1 and the upper flange 4; the bellows connecting block 2 is positioned in the central chamber 7; the diaphragm capsule 8 to be tested is positioned in the central chamber 7 and is welded between the upper flange 4 and the diaphragm capsule connecting block 2; one end of the connecting shaft 5 penetrates through the upper flange 4 and the to-be-detected diaphragm capsule 8 in sequence and then is in threaded connection with the diaphragm capsule connecting block 2, and the other end of the connecting shaft 5 is fixedly connected with the connecting disc 6 through a countersunk head bolt; an annular boss 9 is arranged in the middle of the upper flange 4, the connecting shaft 5 penetrates through the middle of the annular boss 9, and a positioning hole 10 which is perpendicular to the connecting shaft 5 and is provided with threads is arranged on the annular boss 9; the connecting disc 6 is used for being connected with an upper joint of an external tensile testing machine.
In order to know the zero point of the compression amount of the diaphragm capsule 8 to be measured under the condition of not being influenced by other factors, the side wall of the annular boss 9 of the upper flange 4 is provided with a positioning hole 10 vertical to the connecting shaft. When the diaphragm capsule 8 to be tested is placed in the horizontal direction, the connecting shaft 5 sequentially penetrates through the upper flange 4, the diaphragm capsule 8 to be tested and the diaphragm capsule connecting block 2 to be in threaded connection, the set screw is screwed into the positioning hole, the connecting shaft 5 and the upper flange 4 are fixed, the connecting shaft 5 and the connecting disc 6 are fixed, then the connecting disc 6 and the upper joint of the tensile testing machine are connected, the lower flange 1 is connected with the lower joint of the tensile testing machine, and the indication of the tensile testing machine is the zero point of the compression amount of the diaphragm capsule to be.
The side wall of the lower flange 1 is provided with an air hole connected with the inside, and the pressure of the diaphragm capsule test environment can be adjusted through the air hole according to preset conditions. If a diaphragm capsule pressurizing environment test is carried out, the air hole is connected with a pressurizing air inlet pipeline joint to pressurize the central chamber 7; if the membrane box is tested in the normal pressure environment, the air hole is emptied; if the bellows vacuum environment test is carried out, the air hole is connected with a pipeline joint of a vacuum pump, and the central chamber 7 is vacuumized.
The central chamber 7 can be filled with liquid hydrogen, liquid oxygen, methane, oxygen-enriched gas, dinitrogen tetroxide, hydrazine media, water, nitrogen, air, kerosene, fuel oil and other media through air holes on the side wall of the lower flange 1.
The static sealing ring 3 can be adjusted adaptively in order to meet different test environment temperatures. Under the low-temperature working condition, the static sealing ring 3 can be made of polytetrafluoroethylene materials; under the high-temperature working condition, the static sealing ring 3 can be made of high-temperature alloy materials; under the normal temperature working condition, the static sealing ring 3 can adopt an O-shaped rubber ring; under the working condition of high and low temperature change, the static sealing ring 3 can be made of flexible graphite materials.
In order to ensure that the equipment is not dislocated during assembly, the equipment can be centered by key groove type through holes which are circumferentially and uniformly distributed on the connecting disc 6, and then a set screw is screwed in to fix the connecting disc 6 and the upper joint of the testing machine.
The adjustable diaphragm box pressure-bearing fatigue performance test method comprises the following steps:
1) welding a diaphragm capsule 8 to be tested between a diaphragm capsule connecting block 2 and an upper flange 4, placing a static sealing ring 3 between a lower flange 1 and the upper flange, connecting and fixing the upper flange 4 and the lower flange 1 through bolts, and sequentially penetrating a connecting shaft 5 through the upper flange 4 and the diaphragm capsule 8 to be tested to be fixed with the diaphragm capsule connecting block 2 through threads; screwing a set screw from a side wall positioning hole 10 of an upper flange 4, fixing a connecting shaft 5 and the upper flange 4, connecting and fixing the connecting shaft 5 and a connecting disc 6 by adopting a countersunk bolt, centering equipment through a key groove type through hole of the connecting disc 6, connecting the connecting disc 6 with an upper joint of a tensile testing machine, connecting a lower flange 1 with a lower joint of the tensile testing machine, reading the number of the tensile testing machine at the moment as a zero point of the compression amount of a diaphragm box, and then detaching the set screw at the side wall positioning hole 10 of an annular boss 9 on the upper flange 4;
2) controlling the position of an upper joint of the tensile testing machine in the vertical direction, and setting the initial compression amount of the diaphragm capsule 8 to be tested;
3) the test conditions are controlled by adjusting or replacing the pressure, the pressurizing medium and the ambient temperature in the central chamber 7;
4) and (3) carrying out a corresponding capsule pressure-bearing fatigue performance test according to the preset requirement, thus obtaining the pressure-bearing fatigue performance of the capsule 8 to be tested under various environments such as preset pressure, temperature, medium and the like.
5) And (3) replacing the diaphragm capsule 8 to be tested for many times according to preset conditions, repeating the steps 1) to 4) and changing the test conditions in the step 3), so that the bearing fatigue performance of the diaphragm capsule 8 to be tested under different environmental test conditions can be obtained.
The above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same, and it is obvious for a person skilled in the art to modify the specific technical solutions described in the foregoing embodiments or to substitute part of the technical features, and these modifications or substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions protected by the present invention.