阅读说明：本技术 一种容积可变的电爆管输出压力测试系统 (Volume-variable electric detonator output pressure test system ) 是由 许志宇 李小明 谭永华 李永锋 胡攀 于 2019-11-15 设计创作，主要内容包括：为了解决现有的电爆管输出压力测试方案容积固定导致估算误差较大、成本高、难以满足高压高温技术要求、以及不利于测试操作的问题,本发明提供了一种容积可变的电爆管输出压力测试系统。本发明的测试容腔采用直通道结构,依靠待测电爆管出口和霍普金森压杆加载端的端面形成的空腔,通过霍普金森压杆在测试容腔内轴向移动实现所述空腔的容积任意可变,能够适用于电爆管在不同容积小容腔中输出压力特性的测试,通用性好,成本低。将待测电爆管安装在本发明测试容腔的电爆管安装螺孔中后,待测电爆管与霍普金森压杆加载端之间的空腔容积即为电爆管的真实爆腔容积,因此,能够准确计算待测电爆阀工作裕度。(In order to solve the problems that an existing electric detonator output pressure testing scheme is large in estimation error, high in cost, difficult to meet technical requirements of high pressure and high temperature and not beneficial to testing operation due to the fact that the volume is fixed, the invention provides an electric detonator output pressure testing system with a variable volume. The test cavity provided by the invention adopts a straight channel structure, the volume of the cavity can be randomly changed by means of the axial movement of the Hopkinson pressure bar in the test cavity by means of the cavity formed by the outlet of the electric detonation tube to be tested and the end surface of the loading end of the Hopkinson pressure bar, and the electric detonation tube output pressure characteristic test cavity can be suitable for testing the output pressure characteristics of the electric detonation tube in small cavities with different volumes, and is good in universality and low in cost. After the electric explosion tube to be tested is arranged in the electric explosion tube mounting screw hole of the test accommodating cavity, the volume of a cavity between the electric explosion tube to be tested and the loading end of the Hopkinson pressure bar is the real explosion cavity volume of the electric explosion tube, so that the working margin of the electric explosion valve to be tested can be accurately calculated.)

1. A volume-variable output pressure test system for an electric detonator comprises a test cavity, a Hopkinson pressure bar type reflection pressure sensor assembly, an adjustable support seat assembly, a support ring sleeve assembly, a buffer, a strain tester and an oscilloscope, wherein the test cavity is provided with a pressure sensor;

the method is characterized in that:

the test cavity is a straight channel test cavity (2) and is a cylinder with two open ends, and one end of the test cavity is provided with an electric detonator mounting threaded hole (12) for mounting an electric detonator to be tested;

the Hopkinson pressure bar type reflection pressure sensor assembly comprises a Hopkinson pressure bar (7), a metal protection gasket (3), a dynamic strain gauge (6), a head guide sleeve (4), a tail guide sleeve (9) and an O-shaped rubber sealing ring (5);

the metal protection gasket (3) is arranged at the loading end of the Hopkinson pressure bar (7);

the dynamic strain gauge (6) is arranged in the middle of the Hopkinson pressure bar (7);

the head guide sleeve (4) is of a hollow cylindrical structure with two open ends, and the outer side wall of one end of the head guide sleeve is provided with a convex shoulder (11); a sealing ring surface for mounting the O-shaped rubber sealing ring (5) is arranged on the inner side wall of the head guide sleeve (4), and lubricating grease is uniformly coated on the sealing ring surface;

the tail guide sleeve (9) is of a cylindrical structure with openings at two ends, the inner wall of the tail guide sleeve is provided with a sealing ring surface for mounting the O-shaped rubber sealing ring (5), and lubricating grease is uniformly coated on the sealing ring surface;

the head guide sleeve (4) and the tail guide sleeve (9) are sleeved outside the Hopkinson pressure bar (7) to form a supporting structure of the Hopkinson pressure bar (7) together; the head guide sleeve (4) is close to a loading end of the Hopkinson pressure bar (7), the head guide sleeve and the Hopkinson pressure bar are in clearance fit, and the clearance on one side is 10-20 micrometers; the tail guide sleeve (9) is close to the unloading end of the Hopkinson pressure bar (7), and the two are in clearance fit;

the adjustable support assembly comprises a first adjustable support seat (1), a second adjustable support seat (13) and a third adjustable support seat (14);

the support ring sleeve assembly comprises a first support ring sleeve (8) and a second support ring sleeve (15);

the straight channel test chamber (2) is arranged on the first adjustable supporting seat (1), the first supporting ring sleeve (8) is arranged on the second adjustable supporting seat (13), and the second supporting ring sleeve (15) is arranged on the third adjustable supporting seat (14);

one end of the head guide sleeve (4) is arranged in the straight channel test cavity (2), the other end of the head guide sleeve is arranged in the first supporting ring sleeve (8), and the axial position of the head guide sleeve is limited by the convex shoulder (11); the outer wall of the head guide sleeve (4) is in clearance fit with the inner wall of the straight channel test cavity (2) by adopting a clearance fit with 20-50 microns on one side;

the tail guide sleeve (9) is arranged in the second supporting ring sleeve (15);

the straight channel test cavity (2), the Hopkinson pressure bar (7), the head guide sleeve (4), the first support ring sleeve (8) and the second support ring sleeve (15) are coaxially arranged, and the Hopkinson pressure bar (7) can axially move in the head guide sleeve (4) and the tail guide sleeve (9); the tail guide sleeve (9) and the Hopkinson pressure bar (7) are limited by the buffer (10).

2. An electric detonator output pressure test system of claim 1 wherein: the metal protection gasket (3) is a circular metal sheet with the thickness of 0.5mm and the diameter equal to that of the Hopkinson pressure bar (7).

3. An electric detonator output pressure test system of claim 2 wherein: the metal protection gasket (3) is adhered to the loading end of the Hopkinson pressure bar (7) through epoxy resin.

4. An electric detonator output pressure test system of claim 3 wherein: the lubricating grease is 3# molybdenum disulfide lithium-based lubricating grease.

5. An electric detonator output pressure test system of any one of claims 1 to 4 wherein: the length of the head guide sleeve (4) and the length of the tail guide sleeve (9) are 50-100 mm.

Technical Field

The invention relates to an output pressure test system of an electric detonator with variable volume, which is used for testing the pressure output characteristics of a standard electric detonator in different small cavities, can be widely applied to other initiating explosive devices, such as an initiator and the like, and can also be used for testing the detonation pressure performance of explosives and powders.

Background

The electric explosion valve utilizes high-pressure gas generated by explosion of explosive in the electric explosion tube to drive the piston to move, so that a flow path is quickly opened and closed, and the electric explosion valve is commonly used for an aerospace propulsion system. The output pressure of the electric explosion tube directly determines the working margin and reliability of the electric explosion valve, and therefore, the output pressure is a key parameter for designing and researching the electric explosion valve. In order to obtain the output characteristic of the electric detonator, a closed exploder test scheme is generally adopted, and the output characteristic of the electric detonator is characterized by using a pressure curve tested by a pressure sensor.

The existing electric detonator output pressure test scheme has the following problems:

1) the adopted standard closed exploder has two specifications of 27ml and 50ml, which are far larger than the real explosion cavity volume of the electric explosion valve, and the real cavity explosion pressure error estimated through the ideal gas isothermal process is larger, which is not beneficial to accurately calculating the working margin of the electric explosion valve.

2) In order to obtain the output pressure of the electric detonator in the real cavity, closed exploders with different volumes need to be designed according to specific products, and the test scheme has no universality and high cost.

3) The real volume of the product is very small, the output pressure of the electric detonator is high (>100MPa), the gas temperature is high (>2000K), a large amount of high-temperature metal chips and metal oxide particles fly out, the destructiveness is extremely strong, and the existing sensor cannot completely meet the technical requirements.

4) The current Hopkinson pressure bar pressure measurement scheme adopts an integrated supporting sleeve structure, so that high-pressure and high-frequency tests can be realized, but the Hopkinson pressure bar is longer (1m magnitude), so that high requirements are provided for the processing technology of a long and thin sleeve, and the test operation is not facilitated.

Disclosure of Invention

In order to solve the problems that an existing electric detonator output pressure testing scheme is large in estimation error, high in cost, difficult to meet technical requirements of high pressure and high temperature and not beneficial to testing operation due to the fact that the volume is fixed, the invention provides an electric detonator output pressure testing system with a variable volume.

The technical scheme of the invention is as follows:

a volume-variable output pressure test system for an electric detonator comprises a test cavity, a Hopkinson pressure bar type reflection pressure sensor assembly, an adjustable support seat assembly, a support ring sleeve assembly, a buffer, a strain tester and an oscilloscope, wherein the test cavity is provided with a pressure sensor;

it is characterized in that:

the test cavity is a straight channel test cavity and is a cylinder with two open ends, and one end of the test cavity is provided with an electric detonator mounting threaded hole for mounting an electric detonator to be tested;

the Hopkinson pressure bar type reflection pressure sensor assembly comprises a Hopkinson pressure bar, a metal protection gasket, a dynamic strain gauge, a head guide sleeve, a tail guide sleeve and an O-shaped rubber sealing ring;

the metal protective gasket is arranged at the loading end of the Hopkinson pressure bar;

the dynamic strain gauge is arranged in the middle of the Hopkinson pressure bar;

the head guide sleeve is of a hollow cylindrical structure with two open ends, and the outer side wall of one end of the head guide sleeve is provided with a convex shoulder; a sealing ring surface for mounting the O-shaped rubber sealing ring is arranged on the inner side wall of the head guide sleeve, and lubricating grease is uniformly coated on the sealing ring surface;

the tail guide sleeve is of a cylindrical structure with openings at two ends, the inner wall of the tail guide sleeve is provided with a sealing ring surface for mounting an O-shaped rubber sealing ring, and lubricating grease is uniformly coated on the sealing ring surface;

the head guide sleeve and the tail guide sleeve are sleeved outside the Hopkinson pressure bar to form a support structure of the Hopkinson pressure bar together; the head guide sleeve is close to a loading end of the Hopkinson pressure bar, the head guide sleeve and the Hopkinson pressure bar are in clearance fit, and the clearance on one side is 10-20 micrometers; the tail guide sleeve is close to the unloading end of the Hopkinson pressure bar, and the tail guide sleeve and the Hopkinson pressure bar are in clearance fit;

the adjustable support assembly comprises a first adjustable support seat, a second adjustable support seat and a third adjustable support seat;

the support ring sleeve assembly comprises a first support ring sleeve and a second support ring sleeve;

the straight channel test cavity is arranged on the first adjustable supporting seat 1, the first supporting ring sleeve is arranged on the second adjustable supporting seat, and the second supporting ring sleeve is arranged on the third adjustable supporting seat;

one end of the head guide sleeve is arranged in the straight channel test containing cavity, the other end of the head guide sleeve is arranged in the first supporting ring sleeve, and the axial position of the head guide sleeve is limited by the shoulder; the outer wall of the head guide sleeve is in clearance fit with the inner wall of the straight channel test cavity by adopting a single side 20-50 microns;

the tail guide sleeve is arranged in the second support ring sleeve;

the straight channel test cavity, the Hopkinson pressure bar, the head guide sleeve, the first support ring sleeve and the second support ring sleeve are coaxially arranged, and the Hopkinson pressure bar can axially move in the head guide sleeve and the tail guide sleeve; the tail guide sleeve and the Hopkinson pressure bar are limited by the buffer.

Furthermore, the metal protection gasket is a circular metal sheet with the thickness of 0.5mm and the diameter equal to that of the Hopkinson pressure bar.

Furthermore, the metal protection gasket is pasted at the loading end of the Hopkinson pressure bar through epoxy resin.

Further, the grease is 3# molybdenum disulfide lithium-based grease.

Further, the length of the head guide sleeve and the length of the tail guide sleeve are 50-100 mm.

Compared with the prior art, the invention has the beneficial effects that:

1. the test cavity provided by the invention adopts a straight channel structure, the volume of the cavity can be randomly changed by means of the axial movement of the Hopkinson pressure bar in the test cavity by means of the cavity formed by the outlet of the electric detonation tube to be tested and the end surface of the loading end of the Hopkinson pressure bar, and the electric detonation tube output pressure characteristic test cavity can be suitable for testing the output pressure characteristics of the electric detonation tube in small cavities with different volumes, and is good in universality and low in cost.

2. After the electric explosion tube to be tested is arranged in the electric explosion tube mounting screw hole of the test accommodating cavity, the volume of a cavity between the electric explosion tube to be tested and the loading end of the Hopkinson pressure bar is the real explosion cavity volume of the electric explosion tube, so that the working margin of the electric explosion valve to be tested can be accurately calculated.

3. According to the invention, the high-pressure high-frequency test of the small cavity is realized by adopting the Hopkinson pressure bar type reflection pressure sensor assembly, and the metal protection gasket is arranged at the end part of the loading end of the Hopkinson pressure bar, so that the Hopkinson pressure bar is prevented from being damaged and ablated by the impact of metal debris, and the Hopkinson pressure bar can be repeatedly used in a high-temperature and high-pressure test environment.

4. The shoulder is arranged on the head guide sleeve, the axial position of the head guide sleeve can be limited by the shoulder, and the volume of an explosion cavity of the electric explosion valve to be measured can be accurately measured.

5. The support structure of the Hopkinson pressure bar adopts a sectional design in a form of a head guide sleeve and a tail guide sleeve, so that an integral support sleeve with the same length as the Hopkinson pressure bar is prevented from being processed, and the support structure is more convenient to process and use.

Drawings

Fig. 1 is a schematic structural view of an electric squib output pressure test system of the present invention (strain gauges and oscilloscopes are not shown).

Fig. 2 is a schematic structural view of a hopkinson pressure bar type reflective pressure sensor assembly according to the present invention.

FIG. 3 is a schematic view of a straight channel test chamber and variable volume of the present invention.

Description of reference numerals:

1-a first adjustable supporting seat, 2-a straight channel testing cavity, 3-a metal protective gasket, 4-a head guide sleeve, 5-an O-shaped rubber sealing ring, 6-a dynamic strain gauge, 7-a Hopkinson pressure bar, 8-a first supporting ring sleeve, 9-a tail guide sleeve, 10-a buffer, 11-a shoulder, 12-an electric blasting tube mounting threaded hole, 13-a second adjustable supporting seat, 14-a third adjustable supporting seat, 15-a second supporting ring sleeve and 16-a cavity.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

As shown in fig. 1, the volume-variable output pressure testing system for an electric squib provided in this embodiment includes a straight channel testing chamber 2, a hopkinson pressure bar type reflection pressure sensor assembly, a first supporting ring sleeve 8, a second supporting ring sleeve 15, a first adjustable supporting seat 1, a second adjustable supporting seat 13, a third adjustable supporting seat 14, a buffer 10, a strain gauge, and an oscilloscope.

As shown in fig. 2, the hopkinson pressure bar type reflection pressure sensor assembly includes a hopkinson pressure bar 7, a metal protection gasket 3, a dynamic strain gauge 6, a head guide sleeve 4, a tail guide sleeve 9, and an O-shaped rubber seal ring 5.

The metal protection gasket 3 is adhered to the loading end of the Hopkinson pressure bar 7 through epoxy resin; the metal protection gasket 3 can protect the Hopkinson pressure bar 7, so that the Hopkinson pressure bar 7 is prevented from being damaged and ablated by the impact of metal fragments, and the high-temperature and metal fragment impact environment test is realized, so that the Hopkinson pressure bar 7 can be repeatedly used; the metal protection gasket 3 is a consumable replaceable product and can be replaced; the metal protective gasket 3 is preferably a thin metal sheet of uniform thickness of 0.5mm and the same diameter as the diameter of the hopkinson strut 7.

The dynamic strain gauge 6 is arranged on the Hopkinson pressure bar 7 at a position which is about 150mm away from the loading end, and is used for sensing the dynamic strain generated by the Hopkinson pressure bar 7. The dynamic strain gauge 6 is connected with the input end of the strain tester, the electric signal of the dynamic strain gauge 6 is collected and amplified through the strain tester, and then the electric signal is displayed through the oscilloscope.

The head guide sleeve 4 is a hollow cylindrical structure with two open ends, and the outer side wall of one end of the head guide sleeve is provided with a convex shoulder 11; the inner side walls of the two end parts of the head guide sleeve 4 are respectively provided with a sealing ring surface for mounting an O-shaped rubber sealing ring 5, and 3# molybdenum disulfide lithium-based lubricating grease is uniformly coated on the sealing ring surface;

the head guide sleeve 4 is one of the key structures of the invention, and is used for realizing three functions:

① the outer wall of the head guide sleeve 4 and the inner wall of the straight channel test cavity 2 are in clearance fit with 20-50 microns, play a role in clearance sealing at the moment of explosion, and can discharge gas pressure after the test is finished;

② the inner wall of the head guide sleeve 4 is matched with the outer wall of the Hopkinson pressure bar 7 and sealed by the O-shaped rubber sealing ring 5, so that the gas is prevented from entering the gap between the head guide sleeve 4 and the Hopkinson pressure bar 7 and the circumferential free state of the Hopkinson pressure bar 7 is prevented from being influenced by vibration;

③ shoulder 11 on the head guide sleeve 4, used to limit the axial position of the head guide sleeve 4, and the distance between the end face of the straight channel test cavity 2 and the shoulder 11 can accurately obtain the volume of the sealed cavity between the electro-explosive valve to be tested and the Hopkinson pressure bar 7.

The tail guide sleeve 9 is of a hollow cylindrical structure with openings at two ends, a sealing ring surface for mounting the O-shaped rubber sealing ring 5 is arranged on the inner side wall of the tail guide sleeve, and 3# molybdenum disulfide lithium-based lubricating grease is uniformly coated on the sealing ring surface; the tail guide sleeve 9 and the Hopkinson pressure bar 7 are in clearance fit, and the O-shaped rubber sealing ring 5 is adopted to realize sound insulation, so that the circumferential free state of the Hopkinson pressure bar 7 is ensured.

The head guide sleeve 4 and the tail guide sleeve 9 are sleeved outside the Hopkinson pressure bar 7 to jointly form a support structure of the Hopkinson pressure bar 7, and the split design avoids processing an integrated support sleeve with the same length as the Hopkinson pressure bar 7; if the Hopkinson pressure bar 7 is longer, one or more tail guide sleeves 9 can be additionally arranged in the middle of the Hopkinson pressure bar 7.

During assembly, the head guide sleeve 4 is installed from the loading end of the Hopkinson pressure bar 7, and the tail guide sleeve 9 is installed from the unloading end of the Hopkinson pressure bar 7 so as to avoid passing through the position of the dynamic strain gauge 6.

Because the axial length of head uide bushing 4 and afterbody uide bushing 9 is about 50 ~ 100mm, far shorter than hopkinson pressure bar 7's length (1000mm of an order of magnitude), replaced the tradition with the isometric support sleeve structure of hopkinson pressure bar 7, avoid dynamic strain gauge 6's lead wire to pass between hopkinson pressure bar 7 and support sleeve, convenient assembly and use.

As shown in fig. 3, the straight channel test chamber 2 is a thick-walled cylinder structure with openings at two ends, and the wall thickness and material of the cylinder are determined according to the output pressure of the electric detonator to be tested; one end of the straight channel test cavity 2 is provided with an electric detonation tube mounting threaded hole 12 for mounting an electric detonation tube to be tested, and the other end of the straight channel test cavity is used for placing a Hopkinson pressure bar type reflection pressure sensor assembly;

the cavity of the straight channel testing cavity 2 is open, a cavity 16 with adjustable volume is arranged between the outlet of the electric detonator to be tested and the end surface of the metal protective gasket 3, and when the Hopkinson pressure bar 7 moves axially, the volume of the cavity 16 between the outlet of the electric detonator to be tested and the end surface of the metal protective gasket 3 changes. The volume of the cavity is equal to the distance from the outlet of the electric detonator to be measured to the end face of the metal protection gasket 3 multiplied by the inner circular area of the cross section of the straight channel test cavity 2, and the inner circular area of the cross section of the straight channel test cavity 2 is a fixed value once being manufactured, so the volume of the cavity is determined by the distance from the outlet of the electric detonator to be measured to the end face of the metal protection gasket 3, and the distance can be indirectly measured by the following two modes:

① before the electric detonator to be tested is installed, the position and state of the end face of the metal protection gasket 3 are observed from the electric detonator installation threaded hole 12, the distance between the outer end face of the straight channel test cavity 2 and the end face of the metal protection gasket 3 is measured by a depth ruler, and is recorded as delta H, and the distance delta H minus the depth of the electric detonator installation threaded hole 12 is the distance from the outlet of the electric detonator to be tested to the end face of the metal protection gasket 3.

② the distance from the shoulder 11 of the head guide sleeve 4 to the end face of the outlet of the straight channel test chamber 2 is measured by a vernier caliper and recorded as delta L, and the distance from the outlet of the electric detonator to be tested to the end face of the metal protection gasket 3 is calculated by using the actual axial dimension of the head guide sleeve 4 and the actual axial dimension of the straight channel test chamber 2.

As shown in fig. 3, in the invention, the straight channel test chamber 2 is arranged on the first adjustable support seat 1, the first support ring sleeve 8 is arranged on the second adjustable support seat 13, and the second support ring sleeve 15 is arranged on the third adjustable support seat 14;

the Hopkinson pressure bar type reflection pressure sensor assembly is supported by the first supporting ring sleeve 8 and the second supporting ring sleeve 15, and one end of the head guide sleeve 4 and the loading end of the Hopkinson pressure bar 7 in the Hopkinson pressure bar type reflection pressure sensor assembly are positioned in the straight channel test cavity 2 and are positioned at a tested position;

and the straight channel test cavity 2, the Hopkinson pressure bar type reflection pressure sensor assembly, the first support ring sleeve 8 and the second support ring sleeve 15 are coaxially arranged, the Hopkinson pressure bar 7 can axially move in the head guide sleeve 4 and the tail guide sleeve 9, the head guide sleeve 4 is limited by the first support ring sleeve 8, and the tail guide sleeve 9 and the Hopkinson pressure bar 7 are limited by the buffer 10.

The working principle of the invention is as follows:

the volume variable function is realized by the cooperation of the straight channel test cavity 2 and the Hopkinson pressure bar type reflection pressure sensor, and the high-voltage and high-frequency test of the output pressure of the electric detonator to be tested is realized by the Hopkinson pressure bar type reflection pressure sensor component.