Device for measuring deformation of cylinder under impact internal pressure

Abstract

The invention discloses a device for measuring the internal pressure deformation of a cylinder under impact. The device comprises a shell structure, an ignition structure and a main body fixing and sealing structure, the shell structure accommodates the main body fixing and sealing structure, and the tail end accommodates the ignition structure; the ignition structure is fixed in the shell structure; the main body fixing and sealing structure is fixed in a stepped hole at the front end of an inner hole of the shell structure; gas generated after the primer is ignited enters the cylindrical sample, the inner wall of the sample expands in the radial direction under the action of impact internal pressure and axial constraint, the deformation amount is measured by the strain gauge, and an external wire of the strain gauge penetrates out of an inner hole of the shell, so that deformation data is obtained; a pressure measuring device on the shell body is communicated with the inner hole so as to measure the inner pressure; when the internal pressure is too large, the sealing piece is broken through, so that high-pressure gas escapes outwards, and overpressure protection is achieved; and meanwhile, a pressure relief bolt is arranged to ensure safety. The device can measure the deformation process of the cylinder sample under the action of different impact internal pressure levels, and can effectively ensure the test safety.

Description

Technical Field

[0001] The invention belongs to the field of testing deformation of a cylinder under internal pressure, in particular to a device for measuring deformation of a cylinder under impact internal pressure. Background Art

[0002] Cylindrical pressure vessels are widely used in industries such as oil and gas, nuclear energy, electricity and chemical industry. In the field of ammunition, bullet shells and artillery cartridges are also used as cylindrical pressure vessels to withstand the pressure inside the chamber, especially the impact internal pressure under instantaneous loading. Determining the deformation process of the cylinder under the impact internal pressure has important guiding significance for improving its material and structural design.

[0003] At present, the measurement of cylinders deformed by internal pressure is mostly concentrated under quasi-static loading conditions. However, these loading devices are usually large and inconvenient to operate. Under impact loads, digital image correlation technology is often used to test the state of the cylinder before and after deformation to evaluate its mechanical properties, but this method cannot obtain the deformation data of the cylinder during the internal pressure process, especially when the cylinder only undergoes elastic deformation, it is difficult to obtain its maximum elastic deformation data. Summary of the invention

[0004] The object of the present invention is to provide a device for measuring the deformation of a cylinder under impact internal pressure, so as to measure the deformation amount of a thin-walled cylinder structure caused by impact internal pressure.

[0005] The technical solution to achieve the purpose of the present invention is:

[0006] A device for measuring the deformation of a cylinder under impact internal pressure, comprising a shell structure, an ignition structure, an auxiliary winding shaft, a main body fixing and a sealing structure;

[0007] The ignition structure is used to generate gunpowder gas, and the gas is pressurized inside the multi-shell structure;

[0008] The main body fixing and sealing structure includes a tail end fixing part, a tail end rubber ring, a copper lining, a front end rubber ring, a strain gauge, a front end fixing part and a sealing structure;

[0009] The shell structure is coaxially provided with a front stepped hole A, a front stepped hole B and a front stepped hole C with successively increasing apertures; a pressure measuring device and a pressure relief device are provided thereon;

[0010] The tail end fixing piece is arranged in the front end stepped hole A and fits with the front end stepped hole A; the front end fixing piece is arranged in the front end stepped hole C and fits with the front end stepped hole C; the front end stepped hole B is used to accommodate the cylindrical sample, and an annular gap is provided between the cylindrical sample and the front end stepped hole B;

[0011] The tail end rubber ring and the front end rubber ring are respectively arranged at the two ends of the cylindrical specimen; the auxiliary winding shaft is used to wind the liner and form a cylindrical shape; the cylindrical specimen is sleeved on the outside of the liner; the tail end fixing part and the front end fixing part are used to axially limit the two ends of the cylindrical specimen; the auxiliary winding shaft can be withdrawn from the front end fixing part; the strain gauge is pasted on the outside of the cylindrical specimen, and its external wire passes through the front end fixing part; the sealing structure is used to seal the wire hole of the front end fixing part; the tail end fixing part serves as a gas inlet component, and the front end fixing part serves as a regulating component for adjusting the maximum impact internal pressure.

[0012] Compared with the prior art, the present invention has the following significant advantages:

[0013] (1) A copper lining is added to the inside of the sample. The deformation of the copper lining caused by the high-pressure gas causes the outer sample to deform. This allows the high-pressure gas to be measured without directly acting on the sample surface. This also avoids the damage of the strain gauge to the high-pressure gas.

[0014] (2) The axial constraint of the specimen is achieved by adding fixings at both ends of the specimen, thus avoiding the influence of the fixture itself on the axial deformation of the specimen when the fixture is used;

[0015] (3) A double safety pressure relief device consisting of a copper sealing plate and a pressure relief bolt is used to effectively control the impact internal pressure during the test and ensure test safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the front view of the whole set of devices for measuring the deformation of a cylinder under impact internal pressure;

[0017] Figure 2 It is a schematic diagram of the structure of a whole set of devices for measuring the deformation of a cylinder under impact internal pressure;

[0018] Figure 3 It is a schematic diagram of ignition structure I;

[0019] Figure 4 It is an overview of the main body fixing and sealing structure II;

[0020] Figure 5 — Figure 6 It is a schematic diagram of the preliminary assembly process of the main body fixing and sealing structure II;

[0021] Figure 7 It is a schematic diagram of the front end fixing and sealing structure;

[0022] Figure 8 It is a schematic diagram of the later assembly process of the main body fixing and sealing structure II;

[0023] Fig. 9It is a schematic diagram of the location of the strain gauge and its external wires;

[0024] Fig.10 — Fig.11 It is a schematic diagram of the assembly process of the main body fixing and the sealing structure II in the inner hole of the shell;

[0025] Fig.12 It is a schematic diagram of the shell structure;

[0026] Fig.13 It is a schematic diagram of the structure of pressure measuring device III;

[0027] Fig.14 It is a schematic diagram of the structure of pressure relief device IV.

[0028] Among them: Ⅰ- ignition structure Ⅱ- main body fixing and sealing structure Ⅲ- pressure measuring device Ⅳ- pressure relief device A- stepped hole AB inside the shell- stepped hole B inside the shell C- stepped hole C inside the shell D- stepped surface D inside the pressure measuring bolt E- stepped surface E inside the pressure relief hole F- stepped surface F inside the pressure relief hole G- stepped surface G inside the pressure relief hole 1- shell 2- pressure measuring bolt 3- pressure measuring device 4- tail end inner fastener 5- tail end outer fastener 6- tail end rubber ring 7- copper lining 8- cylindrical sample 9- front end rubber ring 10- front end inner fastener 11- front end outer fastener 12- sealing pad 13- sealing front cover 14- copper sealing plate 15- sealing inner ring 16- primer 17- cartridge 18- pressure relief bolt 19- strain gauge 20- auxiliary winding shaft DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0030] The complete set of equipment for measuring the deformation of a cylinder under impact internal pressure includes a shell structure, an ignition structure I, a main body fixing and sealing structure II, and the components in each structure must be assembled according to a predetermined design.

[0031] Combination Figure 1 , Figure 2 The outer side of the tail end of the shell structure is connected to the external launching mechanism; the tail end of the inner hole accommodates the ignition structure I, and the front stepped holes A, B, and C accommodate the main body fixing and sealing structure II. After assembly, the main structures in the inner hole remain coaxial and do not move axially during the test.

[0032] Combination Figure 3 The ignition structure I includes a primer 16 and a cartridge case 17. The primer 16 is pre-installed in the primer chamber at the bottom of the cartridge case 17; the cartridge case 17 is installed at the rear end of the inner hole of the shell 1 and fits tightly, and is installed inside the shell 1 from the rear end of the shell forward together with the primer 16 during installation.

[0033] Combination Figure 4The main body fixing and sealing structure II includes a tail end fixing part, a tail end rubber ring 6, a copper lining 7, a cylindrical specimen 8, a front end rubber ring 9, a front end fixing part and a sealing structure, and a strain gauge 19. The main components are kept coaxial and tightly fitted. The front end stepped holes A, B, and C are enlarged in sequence, and are used to place the front end fixing and sealing structure, the cylindrical specimen, and the tail end fixing part respectively; the tail end fixing part fits with the front end stepped hole A, the front end fixing and sealing structure fits with the front end stepped hole C, and there is an annular gap between the cylindrical specimen and the front end stepped hole B.

[0034] The tail end fixing member includes a tail end inner fixing member 4 and a tail end outer fixing member 5, which are connected by threads.

[0035] The front end fixing part includes a front end inner fixture 10, a front end outer fixture 11, a copper sealing piece 14, and a sealing inner ring 15; the copper sealing piece 14 is pressed by the sealing inner ring 15 to the bottom of the inner hole of the front end inner fixture 10, wherein the bottom surface of the front end inner fixture 10 is provided with four evenly arrayed circular holes, so that the copper sealing piece 14 is evenly pressurized, and the high-pressure gas can escape after breaking through the copper sealing piece 14; the front end inner fixture 10 is installed inside the front end outer fixture 11 through a threaded connection; the end faces of the front end outer fixture 11 and the front end rubber ring 9 are each provided with three small through holes to allow the wires of the strain gauge 19 to pass to the outside.

[0036] The sealing structure includes a sealing front cover 13 and a sealing pad 12;

[0037] The specific assembly process of the main body fixing and sealing structure II is as follows Figure 5 — Fig.11 shown.

[0038] Combination Figure 5 , Figure 6 First, install the narrower end of the auxiliary winding shaft 20 in the inner hole of the tail end inner fixture 4, so that the end face of the tail end inner fixture 4 with a smaller outer diameter is tightly fitted with the stepped surface of the auxiliary winding shaft 20; then wrap the copper lining 7 tightly against the outer surface of the auxiliary winding shaft 20, with one side close to the bottom of the external thread of the tail end inner fixture 4, into a cylindrical shape and stick it firmly; then tighten the tail end outer fixture 5 on the tail end inner fixture 4; then axially install the tail end rubber ring 6, the cylindrical sample 8, the front end rubber ring 9, and the front end outer fixture 11 in sequence, and each end face is fitted in sequence during installation.

[0039] Combination Figure 7 , install the copper sealing piece 14 at the bottom of the inner hole of the front end inner fixture 10, and then install the sealing inner ring 15 in the inner hole to press the surface of the copper sealing piece 14.

[0040] Combination Figure 8 , push the auxiliary winding shaft 20 forward, and Figure 7 The front end inner fixture 10 and its internal components are installed together inside the front end outer fixture 11 and tightened.

[0041] Combination Fig. 9 , the strain gauge 19 is pasted on the outside of the cylindrical sample 8, and the strain gauge 19 is connected to an external wire. The wire passes through the small through holes on the front rubber ring 9 and the front external fixture 11 and is connected to the outside from the front end.

[0042] Combination Fig.10 , Fig.11 , insert the assembled whole structure backwards into the inner hole of the shell 1 until the tail end fixing piece fits with the bottom surface of the stepped hole A; install the sealing gasket 12 and the sealing front cover 13 on the outermost side, wherein the sealing front cover 13 has an external thread, which needs to be tightened at the corresponding internal thread at the front end of the shell 1 during installation; pass the external wire of the strain gauge 19 through the inner hole of the sealing gasket 12 to the outside of the device.

[0043] Combination Fig.12 The shell structure includes a shell 1, a pressure measuring device III, and a pressure relief device IV. The outer side of the shell 1 is provided with a pressure measuring hole and a pressure relief hole, and the angle between the axes of the two is 90 degrees; the inner side is provided with a series of stepped holes, among which the front end of the stepped hole C is provided with a thread to connect the sealing front cover 13.

[0044] Combination Fig.13 The pressure measuring bolt 2 in the pressure measuring device III is installed in the pressure measuring hole through a threaded connection, and a stepped through hole is opened on its surface, which can be connected with the inner hole of the shell 1 while accommodating the pressure measuring device 3; the pressure measuring device 3 is installed in the threaded hole of the pressure measuring bolt 2 through a threaded connection, and the bottom is tightly fitted with the stepped surface D of the pressure measuring bolt 2.

[0045] Combination Fig.14 The pressure relief bolt 18 in the pressure relief device IV is installed in the pressure relief hole through a threaded connection, tightly fitting with the step surface E, leaving a gap between its bottom and the step surface G, and having two mutually perpendicular vents inside, which are connected to the external atmosphere and the pressure measuring hole respectively; when the pressure relief bolt 18 is screwed outward until the bottom surface is above the step surface F, the high-pressure gas inside the housing 1 can flow into the vent of the pressure relief bolt 18 and escape outward, thereby achieving pressure relief.

[0046] The working principle of the whole test device during the test is as follows:

[0047] The primer 16 is ignited by the external firing mechanism, and the high-temperature and high-pressure gas generated quickly diffuses to the front of the inner hole of the shell 1, forming an impact internal pressure, and acts on the inner surface of the copper liner 7 to cause it to deform radially, driving the cylindrical sample 8 that is tightly fitted with it on the outside to deform radially. The sealing front cover 13, the sealing gasket 12, the front end fixing parts (components 10, 11), the front end rubber ring 9, the tail end rubber ring 6, and the tail end fixing parts (components 4, 5) are fixed to achieve axial constraint on the cylindrical sample 8. The corresponding radial deformation is measured by the strain gauge 19. The external wire of the strain gauge 19 starts from the surface of the cylindrical sample 8, passes through the through hole on the internal structure and is finally connected to the outside, so as to obtain test data. The copper sealing piece 14 and the sealing inner ring 15 in the front end inner fixture 10 can prevent the leakage of high-pressure gas during the process of increasing internal pressure. When the internal pressure increases to a certain level, the copper sealing piece 14 is broken, and the high-pressure gas passes through the copper sealing piece 14 and escapes from the circular hole on the surface of the front end inner fixture 10, completing the pressure relief and the test ends.

[0048] The maximum value of the impact internal pressure can be controlled by adjusting the thickness of the copper sealing sheet 14. The bottom sensor of the pressure measuring device 3 is connected to the inner hole of the shell 1, and the internal pressure value can be directly measured.

[0049] If the copper sealing piece 14 is not broken during the test, the pressure relief bolt 18 can be loosened to allow the high-pressure gas to escape from the vent hole inside the pressure relief bolt 18, thereby achieving pressure relief and ensuring the safety of the test.

Claims

1. A device for measuring the deformation of a cylinder under impact internal pressure, characterized in that: It includes a shell structure, an ignition structure, an auxiliary winding shaft, a main body fixing and a sealing structure; The ignition structure is used to generate gunpowder gas, and the gas is pressurized inside the multi-shell structure; The main body fixing and sealing structure includes a tail end fixing part, a tail end rubber ring, a copper lining, a front end rubber ring, a strain gauge, a front end fixing part and a sealing structure; The shell structure is coaxially provided with a front stepped hole A, a front stepped hole B and a front stepped hole C with successively increasing apertures; a pressure measuring device and a pressure relief device are provided thereon; The tail end fixing piece is arranged in the front end stepped hole A and fits with the front end stepped hole A; the front end fixing piece is arranged in the front end stepped hole C and fits with the front end stepped hole C; the front end stepped hole B is used to accommodate the cylindrical sample, and an annular gap is provided between the cylindrical sample and the front end stepped hole B; The tail end rubber ring and the front end rubber ring are respectively arranged at the two ends of the cylindrical specimen; the auxiliary winding shaft is used to wind the liner and form a cylindrical shape; the cylindrical specimen is sleeved on the outside of the liner; the tail end fixing part and the front end fixing part are used to axially limit the two ends of the cylindrical specimen; the auxiliary winding shaft can be withdrawn from the front end fixing part; the strain gauge is pasted on the outside of the cylindrical specimen, and its external wire passes through the front end fixing part; the sealing structure is used to seal the wire hole of the front end fixing part; the tail end fixing part serves as a gas inlet component, and the front end fixing part serves as a regulating component for adjusting the maximum impact internal pressure.

2. The device for measuring the deformation of a cylinder under impact internal pressure according to claim 1, characterized in that: The front end fixing part includes a front end inner fixture, a front end outer fixture, a sealing piece, and a sealing inner ring; the sealing piece is pressed by the sealing inner ring to the bottom of the inner hole of the front end inner fixture; a plurality of evenly distributed circular holes are provided on the bottom surface of the front end inner fixture for gas to escape after breaking through the sealing piece; the front end inner fixture is installed inside the front end outer fixture through a threaded connection; the end surfaces of the front end outer fixture and the front end rubber ring are provided with through holes for allowing the wires of the strain gauge to pass to the outside.

3. The device for measuring the deformation of a cylinder under impact internal pressure according to claim 1, characterized in that: The tail end fixing piece includes an inner tail end fixing piece and an outer tail end fixing piece; the inner tail end fixing piece and the outer tail end fixing piece are connected by threads; the inner tail end fixing piece is used to assist in axial positioning of the winding shaft, and the outer tail end fixing piece is used to axially position the tail end rubber ring.

4. The device for measuring the deformation of a cylinder under impact internal pressure according to claim 2, characterized in that: The sealing structure includes a sealing front cover and a sealing pad; a sealing pad and a sealing front cover are arranged on the outside of the front external fixing piece; the sealing front cover has an external thread which is tightened with the internal thread corresponding to the front end of the shell, and the external connecting wire of the strain gauge passes through the inner hole of the sealing pad.

5. The device for measuring the deformation of a cylinder under impact internal pressure according to claim 1, characterized in that: The ignition structure comprises a primer and a cartridge case; the primer is installed in a primer chamber at the bottom of the cartridge case; and the cartridge case is installed at the rear end of the inner hole of the shell and fits tightly.

6. The device for measuring the deformation of a cylinder under impact internal pressure according to claim 1, characterized in that: The pressure measuring device comprises a pressure measuring bolt and a pressure measuring device; the pressure measuring bolt is installed in the pressure measuring hole through a threaded connection, and the pressure measuring device is installed in the threaded hole of the pressure measuring bolt through a threaded connection.

7. The device for measuring the deformation of a cylinder under impact internal pressure according to claim 1, characterized in that: The pressure relief device includes a pressure relief bolt; the pressure relief bolt 18 is installed in the pressure relief hole through a threaded connection, and the pressure relief hole is a stepped hole, including a step surface E, a step surface F and a step surface G whose diameters gradually decrease from top to bottom; the pressure relief bolt fits tightly against the step surface E, and a gap is left between its bottom and the step surface G, and two mutually perpendicular air holes are opened inside, which are connected to the external atmosphere and the pressure measuring hole respectively; when the pressure relief bolt is screwed outward until the bottom surface is above the step surface F, the high-pressure gas inside the shell can flow into the air hole of the pressure relief bolt and escape outward, thereby achieving pressure relief.

8. The device for measuring the deformation of a cylinder under impact internal pressure according to any one of claims 1 to 7, characterized in that: The assembly process is: First, install the narrower end of the auxiliary winding in the inner hole of the tail end inner fixture of the tail end fixture, so that the end face with the smaller outer diameter of the tail end inner fixture is closely fitted with the stepped surface of the auxiliary winding shaft; then wrap the liner tightly against the outer surface of the auxiliary winding shaft, and one side is close to the bottom of the external thread of the tail end inner fixture into a cylindrical shape and stick it firmly; then tighten the tail end outer fixture on the tail end inner fixture of the tail end fixture; then axially install the tail end rubber ring, the cylindrical sample, the front end rubber ring, and the front end outer fixture in sequence, and each end face is fitted in sequence during installation; Install the sealing piece of the front-end fixing piece at the bottom of the inner hole of the front-end inner fixing piece, and then install the sealing inner ring in the inner hole to press the surface of the sealing piece tightly; Push the auxiliary winding shaft forward, and install the front end inner fixing of the front end fixing piece and its internal components together inside the front end outer fixing piece of the front end fixing piece and tighten them; The strain gauge is pasted on the outside of the cylindrical specimen, and the strain gauge is connected to an external wire. The wire is inserted into the front rubber ring and the through hole on the front external fixture and connected to the outside; Insert the installed whole structure backwards into the inner hole of the shell until the tail end fixing fits with the bottom surface of the stepped hole A; install the sealing structure on the outermost side and pass the external connecting wire of the strain gauge through the inner hole of the sealing structure to the outside of the device.

Images