A device for measuring the deformation of a cylinder under internal pressure impact

Abstract

The application discloses a device for measuring the deformation of a cylinder under impact internal pressure, which comprises a shell structure, an ignition structure and a main body fixing and sealing structure; the shell structure contains the main body fixing and sealing structure and accommodates the tail end of the ignition structure; the ignition structure is fixed in the shell structure; the main body fixing and sealing structure is fixed in the stepped hole at the front end of the inner hole of the shell structure; the gas generated after the primer is ignited enters the inside of the cylinder sample, the inner wall of the sample expands radially under the action of the impact internal pressure and the axial constraint, the deformation is measured by a strain gauge, the outer lead wire of the strain gauge passes through the inner hole of the shell body, and thus the deformation data is obtained; a pressure measuring device on the shell body is communicated with the inner hole to measure the internal pressure; when the internal pressure is too large, the sealing sheet is broken, the high-pressure gas escapes outward, and the overpressure protection is realized; meanwhile, a pressure relief bolt is arranged to ensure safety. The device can measure the deformation process of the cylinder sample under 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, power generation, and the chemical industry. In the ammunition industry, bullet cases and artillery cartridges also serve as cylindrical pressure vessels, withstanding internal pressure, particularly the impact pressure under transient loading. Measuring the deformation process of cylindrical vessels under impact pressure is of great significance for improving their material and structural design.

[0003] Currently, measurements of cylinder deformation under internal pressure are mostly performed under quasi-static loading conditions. However, these loading devices are often bulky and difficult to operate. Under impact loading, digital image correlation techniques are often used to measure the cylinder's state before and after deformation to evaluate its mechanical properties. However, this method cannot obtain deformation data during the internal pressure process, especially when the cylinder only deforms elastically, making it difficult to obtain data on its maximum elastic deformation. 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 of a thin-walled cylindrical structure caused by impact internal pressure.

[0005] The technical solutions for achieving the purpose of the present invention are:

[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 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 housing 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 on the front stepped hole.

[0010] The tail end fixing piece is arranged in the front stepped hole A and fits with the front stepped hole A; the front end fixing piece is arranged in the front stepped hole C and fits with the front stepped hole C; the front stepped hole B is used to accommodate the cylindrical sample and an annular gap is provided between the cylindrical sample and the front 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 lining and form a cylindrical shape; the cylindrical specimen is sleeved on the outside of the lining; 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 inner side of the specimen. The deformation of the copper lining caused by the high-pressure gas causes the outer specimen to deform. This eliminates the need for the high-pressure gas to act directly on the specimen surface. The deformation process of the specimen under the impact of the internal pressure can be measured, while avoiding damage to the strain gauge by 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 it is clamped;

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

[0016] Figure 1 This is a schematic diagram of the structure of a complete set of devices for measuring the deformation of a cylinder under impact internal pressure;

[0017] Figure 2 This is a schematic top view of the entire device structure 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 This is an overview of the main body fixing and sealing structure II;

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

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

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

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

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

[0027] Figure 14 It is a structural diagram 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-Inner stepped hole A of the shell B-Inner stepped hole B of the shell C-Inner stepped hole C of the shell D-Inner stepped surface D of pressure measuring bolt E-Inner stepped surface E of pressure relief hole F-Inner stepped surface F of pressure relief hole G-Inner stepped surface G of pressure relief hole 1-Housing 2-Pressure measuring bolt 3-Pressure measuring device 4-Tail inner fastener 5-Tail outer fastener 6-Tail rubber ring 7-Copper lining 8-Cylindrical specimen 9-Front end rubber ring 10-Front end inner fastener 11-Front end outer fastener 12-Sealing gasket 13-Sealing front cover 14-Copper sealing plate 15-Sealing inner ring 16-Primer 17-Cartridge case 18-Pressure relief bolt 19-Strain gauge 20-Auxiliary winding shaft DETAILED DESCRIPTION

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0030] The complete device 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] Combine Figure 1 、 Figure 2 The outer end of the outer shell structure is connected to the external firing mechanism; the inner bore's rear end 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 bore remain coaxial and do not move axially during testing.

[0032] Combine 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. When installed, it is installed inside the shell 1 together with the primer 16 from the rear end of the shell to the front.

[0033] Combine Figure 4The main body fixing and sealing structure II includes the tail end fixing member, tail end rubber ring 6, copper lining 7, cylindrical specimen 8, front end rubber ring 9, front end fixing member and sealing structure, and strain gauge 19. These main components remain coaxial and tightly fitted. Front end stepped holes A, B, and C increase in size, respectively, to accommodate the front end fixing and sealing structure, cylindrical specimen, and tail end fixing member. The tail end fixing member fits into front end stepped hole A, the front end fixing and sealing structure fits into front end stepped hole C, and an annular gap is formed between the cylindrical specimen and 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 against the bottom of the inner hole of the front end inner fixture 10 by the sealing inner ring 15, wherein the bottom surface of the front end inner fixture 10 is provided with four circular holes in a uniform array, 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 gasket 12;

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

[0038] Combine Figure 5 、 Figure 6 First, install the narrower end of the auxiliary winding shaft 20 in the inner hole of the tail end inner firmware 4, so that the end face of the tail end inner firmware 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 end of the external thread of the tail end inner firmware 4, into a cylindrical shape and stick it firmly; then tighten the tail end outer firmware 5 on the tail end inner firmware 4; then axially install the tail end rubber ring 6, cylindrical sample 8, front end rubber ring 9, and front end outer firmware 11 in sequence, and make each end face fit in sequence during installation.

[0039] Combine 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] Combine 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] Combine Figure 9 , stick the strain gauge 19 on the outside of the cylindrical sample 8, connect the strain gauge 19 to the external wire, and pass the wire through the small through hole on the front rubber ring 9 and the front external fixture 11 and connect to the outside from the front end.

[0042] Combine Figure 10 、 Figure 11 , insert the assembled entire structure backward 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, where 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] Combine Figure 12 The housing structure comprises a housing 1, a pressure measuring device III, and a pressure relief device IV. The housing 1 has a pressure measuring hole and a pressure relief hole on its exterior, with their axes forming a 90-degree angle. The interior of the housing has a series of stepped holes, with the front end of stepped hole C threaded for connection to a sealing front cover 13.

[0044] Combine Figure 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 accommodate the pressure gauge 3 and communicate with the inner hole of the shell 1; the pressure gauge 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] Combine Figure 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 hole of the pressure relief bolt 18 and escape outward, thereby achieving pressure relief.

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

[0047] The primer 16 is ignited by the external firing mechanism, generating high-temperature, high-pressure gas that rapidly diffuses toward the front of the inner bore of the shell 1, creating an impact internal pressure that acts on the inner surface of the copper liner 7, causing it to deform radially, driving the cylindrical specimen 8, which is tightly fitted to it on the outside, to deform radially. The sealing front cover 13, sealing gasket 12, front fixings (components 10 and 11), front rubber ring 9, rear rubber ring 6, and rear fixings (components 4 and 5) are stationary to achieve axial constraint on the cylindrical specimen 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 specimen 8, passes through the through-hole in the internal structure, and finally connects to the outside 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 impact internal pressure can be controlled by adjusting the thickness of the copper sealing piece 14. The bottom sensor of the pressure gauge 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 it, thereby achieving pressure relief and ensuring test safety.

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 housing 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 on the front stepped hole. The tail end fixing piece is arranged in the front stepped hole A and fits with the front stepped hole A; the front end fixing piece is arranged in the front stepped hole C and fits with the front stepped hole C; the front stepped hole B is used to accommodate the cylindrical sample and an annular gap is provided between the cylindrical sample and the front stepped hole B; The tail rubber ring and the front 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 fixing piece and the front fixing piece are used to axially limit the two ends of the cylindrical specimen; the auxiliary winding shaft can be withdrawn from the front fixing piece; the strain gauge is pasted on the outside of the cylindrical specimen, and its external wire passes through the front fixing piece; the sealing structure is used to seal the wire hole of the front fixing piece; the tail fixing piece serves as a gas inlet component, and the front fixing piece serves as a regulating component for adjusting the maximum impact internal pressure; The front end fixing member includes a front end inner fixing member, a front end outer fixing member, a sealing plate, and a sealing inner ring; the sealing plate is pressed against the bottom of the inner hole of the front end inner fixing member by the sealing inner ring; the bottom surface of the front end inner fixing member is provided with a plurality of evenly distributed circular holes for gas to escape after breaking through the sealing plate; the front end inner fixing member is mounted inside the front end outer fixing member via a threaded connection; the end surfaces of the front end outer fixing member and the front end rubber ring are provided with through holes for allowing the wires of the strain gauge to pass to the outside; 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.

2. The device for measuring deformation of a cylinder under impact internal pressure according to claim 1, characterized in that: The sealing structure includes a sealing front cover and a sealing gasket; a sealing gasket and a sealing front cover are provided on the outside of the front external fixing member; the sealing front cover has an external thread that 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 gasket.

3. The device for measuring deformation of a cylinder under impact internal pressure according to claim 1, characterized in that: The ignition structure includes 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.

4. The device for measuring 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.

5. The device for measuring 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 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 with diameters gradually decreasing from top to bottom; the pressure relief bolt fits tightly with the step surface E, and a gap is left between its bottom and the step surface G, and two mutually perpendicular air vents 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 vent hole of the pressure relief bolt and escape outward, thereby achieving pressure relief.

6. The device for measuring deformation of a cylinder under impact internal pressure according to any one of claims 1 to 5, characterized in that: The assembly process is: First, install the narrower end of the auxiliary winding into 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 tightly fitted with the stepped surface of the auxiliary winding shaft; then wrap the lining tightly against the outer surface of the auxiliary winding shaft, with one side close to the outer thread bottom of the tail end inner fixture, into a cylindrical shape and glue it firmly; then tighten the tail end outer fixture to the tail end inner fixture of the tail end fixture; then axially install the tail end rubber ring, cylindrical specimen, front end rubber ring, and front end outer fixture in sequence, making sure that each end face fits in sequence during installation; Install the sealing piece of the front fixing piece at the bottom of the inner hole of the front 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 inner fixing piece and its internal components together inside the front outer fixing piece of the front end fixing piece and tighten them; Paste the strain gauge on the outside of the cylindrical specimen, connect the strain gauge to the external wire, insert the wire into the front rubber ring, the through hole on the front external fixture and connect to the outside; Insert the assembled whole structure backward 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 wires of the strain gauge through the inner hole of the sealing structure to the outside of the device.

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