RU206625U1 - LASER PYRO ENERGY SENSOR - Google Patents

Abstract

The utility model relates to the field of safe initiation means using laser radiation sources and can be used for remote control of automation units of rocket and space technology. The laser pyroenergy sensor contains a housing in which an igniter unit with an initiating charge in the recess of the block and a pyrotechnic charge in the cap are located, separated from the initiating charge by a compensating disk and a movable obturating cone resting on a grate, which has a nest with a transfer charge on the side of the pyrotechnic charge. An afterburner is mounted in the muzzle of the body, which supports the cap with a pyrotechnic charge. A centering split sleeve with an optical probe, which is a rod with an internal channel, is installed in the block of the ignition unit. The channel contains an optical fiber, polished flush with the surface of the recess for the initiating charge and separated from it by an optical spacer. The device makes it possible to exclude accidental triggering of the initiation system from the influence of electromagnetic fields, accidental electric discharges, provides speed, minimum delay time, the ability to control the ignition delay time of the initiating charge of the pyroenergy sensor by controlling the radiation power density, minimum study power losses, the possibility of flexible adaptation of the laser initiation system to different requirements and tasks, as well as the ease of implementation of laser initiation of an explosive. 2 c.p. f-ly, 5 dwg

Description

The utility model relates to the field of safe initiation means using laser radiation sources and can be used for remote control of automation units of rocket and space technology.

Known, taken as a prototype, a pyroenergy sensor of a similar purpose (description for patent RU 2088886 C1, 08/27/1997, F42B 3/12), consisting of a housing in which an electric ignition unit is located with conductors passing through an insulator (block), incandescent bridges and an initiating charge , a cap with a pyrotechnic charge, which is pressed by the afterburner. Between the electric ignition unit and the pyrotechnic charge, there is a compensating dielectric disc and a movable obturating cone, which rests on the base on the grate.

When an electric current is applied to the incandescent bridges, the latter heats up and ignites an initiating charge, from the force of the flame of which the transfer and pyrotechnic charges are triggered, the pressure of the gases of which does work to trigger the units (or the corresponding igniter is ignited by the force of the flame).

The specified pyroenergy sensor coincides with the patented utility model in terms of overall and connecting dimensions and the presence of an obturating cone that seals the ignition unit of the pyroenergy sensor after the pyrotechnic charge is triggered, which makes it possible to use it as a locking-obturating device, thereby ensuring reliable functioning of the pyro-space automation units of rocket technology.

Disadvantages:

the possibility of unauthorized operation when the system is exposed to the initiation of electromagnetic fields, accidental electrical discharges;

inability to regulate the response time;

electric bridges of an incandescent can have breakage and defect of soldering.

These disadvantages are associated with the electrical principle of initiation.

It is known to use laser initiation as an alternative to electrical initiation (US patent 8915188 B2, 23.12.2014, F4D 5/00, F42B 3/113, C06C 7/10, F42B 3/18). In one embodiment, the igniter in the detonator structure is triggered by light energy. In the squib, the pyrotechnic composition or explosive (explosive) contacts the end of the optical fiber.

A light beam passing through the optical fiber ignites the first pyrotechnic composition or the first explosive of the pyrotechnic stage, which triggers the detonator.

Disadvantages:

insufficient safety of the product under mechanical stress due to the absence of an optical gasket;

loss of product performance when exposed to high temperatures for more than 30 s.

Known optical initiator (patent FR 2914056 A1, 27.08.1997, F42B 3/113), for example, an initiator of the igniter type containing at least one pyrotechnic charge or explosive initiated by light energy transmitted by an optical fiber. It contains a threaded sleeve with a screwed-in connector with an optical fiber cable placed in it, the polished end of which is glued into the ring and adjoins the pyrotechnic charge.

A beam of light, passing through the optical fiber, ignites a pyrotechnic charge, the thermal energy from the combustion of which burns through the bottom of the cap and, passing through a hole in the metal washer, ignites the explosive in the bottom of the sleeve.

Known is a detonator cap for laser initiation of an explosive (description for patent RU 135789 U1, 12/20/2013, F42B 3/113), which consists of a metal body with sequentially placed contacting weights of the main charge from a blasting explosive, an intermediate shell and an initiating a charge from a blasting explosive, a retarding composition, an incendiary pyrotechnic composition, a bayonet mount of a laser igniting element with a shock absorber with a threaded channel placed on it.

Initiation is carried out using a laser diode with a wavelength of 808 nm, a power of 1 W, operating in a continuous mode, the focusing of laser radiation on the charge surface is performed by an optical system built into the detonator capsule, consisting of a collimating and focusing lens, as well as a sapphire window, optical the fiber does not fit close to the explosive charge and has a core diameter of at least 50 microns.

Disadvantages:

the complexity of the implementation of the initiation of explosives, the loss of radiation power and, as a consequence, significant fluctuations in the power density.

The technical result of the claimed utility model is:

exclusion of the possibility of accidental triggering of the initiation system from exposure to electromagnetic fields, accidental electrical discharges;

speed and the ability to control the ignition delay time of the initiating charge of the squib by controlling the radiation power density;

the possibility of flexible adaptation of the laser initiation system to various requirements and tasks;

ease of implementation of laser initiation of an explosive, minimum delay time, minimum radiation power losses.

The specified technical result is achieved by a laser pyroenergy sensor, in the case of which there is an ignition unit with an initiating charge in the recess of the block and a pyrotechnic charge in the cap, separated from the initiating charge by a compensating disc and a movable obturating cone, resting on a grate, which has a nest with a transferring charge on the side of the pyrotechnic charge , and an afterburner is mounted in the muzzle of the body, supporting the cap with a pyrotechnic charge, while, according to the patented technical solution, a centering split bushing with an optical probe is installed in the block of the igniter assembly, which is a rod with an internal channel containing an optical fiber, polished flush with the surface recesses for the initiating charge and separated from it by an optical spacer.

In the preferred embodiment of the utility model, the pyroenergy sensor uses an HCS-type optical fiber with a core diameter of 205 μm and a cladding diameter of 230 μm, polished on abrasive films with a grain size of 5, 1, 0.3 μm in order of decreasing grain size, and the core is made of glass, and the damper is made of polymer.

In a particular case, the optical spacer is made of fluoroplastic.

The patented technical solution is illustrated by drawings.

FIG. 1 shows a laser pyroelectric sensor;

in fig. 2 - ignition unit of the laser pyroenergy sensor;

in fig. 3 - optical probe;

in fig. 4 - dependence of the delay time of the initiation of charges of lead trinitroresorcinate (TNRS) in the samples on the power density at the output end of the fiber;

in fig. 5 - curve of the triggering pressure of the laser pyroelectric sensor from the laser initiation system.

FIG. 1, 2, 3, the following designations are adopted:

1 - case;

2 - ignition unit;

3 - initiating charge;

4 - block;

5 - pyrotechnic charge;

6 - cap;

7 - compensating disc;

8 - movable obturating cone;

9 - grate;

10 - transfer charge;

11 - afterburner sleeve;

12 - centering split sleeve;

13 - optical probe;

14 - rod;

15 - fiber optic;

16 - optical spacer.

An example of a specific execution

Laser pyroenergy sensor (Fig. 1) in the housing 1 of which there is an ignition unit 2 (Fig. 2) with an initiating charge 3 in the recess of the block 4 and a pyrotechnic charge 5 in the cap 6, separated from the initiating charge 3 by a compensating disc 7 and a movable obturating cone 8, resting on the grate 9, which has a socket with a transfer charge 10 on the side of the pyrotechnic charge 5, and an afterburner 11 is mounted in the muzzle of the body 1, supporting the cap 6 with a pyrotechnic charge 5. In this case, a centering split bushing 12 s is installed in the block 4 of the igniter unit 2 optical probe 13 (Fig. 3), which is a rod 14 with an internal channel, in which the optical fiber 15 is located, polished flush with the surface of the recess for the initiating charge 3 and separated from it by an optical spacer 16.

A detailed description of an example of a specific implementation.

The optical probe 13 used with a length of 15 mm and a diameter of 2.5 mm is a rod 14 with a pressed-in piece of multimode optical fiber 15 of the HCS type 5 m long with insulation along the entire length with a core diameter of 205 μm and a sheath (damper) diameter of 230 μm, in where the core is made of glass, and the damper is made of a special polymer. In fiber 15 with an average refractive index of 1.5, the propagation time of the optical signal is 5 ns / m, which makes it possible to control and measure the response time of the pyroenergy sensor, as well as to provide the required signal delay for a time proportional to its length with an accuracy of at least 1 ns.

The input end of the probe 13 is polished flush with the end of the optical fiber 15. Docking with the ST connector of the optical fiber 15 is carried out by a centering split sleeve 12. The output end of the probe 13 is also polished flush with the optical fiber 15 and screwed on the M2.5 thread into the block 4. The distance from the end to the thread 2 , 3 mm. The threaded connection is sealed with epoxy compound. The initiating charge ТНРС 3 is filled by pressing onto an optical circular spacer 16 with a thickness of 50 microns made of fluoroplastic-4, located on the polished output end of the probe 13 into a recess in the block 4, and coated with a protective varnish.

The PTFE-4 gasket has two functions. Since the refractive index of PTFE-4 for infrared radiation with a wavelength of 808 nm is 1.35, the possibility of radiation reflection back into the fiber is excluded. In addition, the gasket acts as a support, protecting the explosive from contact with the roughness of the body, which is essential in the case of a substance with a high sensitivity to friction.

The choice of the fiber core diameter of 205 μm was dictated by the size of the emitting area of the laser diode and by the fact that the diameter of the radiation spot over the charge surface should be larger than the size of the crystal of the initiating charge of the THPC.

Principle of operation

The radiation of the laser diode through the optical fiber 15 causes heating and ignition of the initiating charge 3, from the force of the flame of which the transfer charge 10 is triggered. When this charge is triggered, the obturating cone 8 is jammed and the composition of the pyrotechnic charge 5 is ignited, the gas pressure of which performs mechanical work on the triggering of various units, or the force of the flame ignites the corresponding pyrotechnic, gunpowder and other charges.

Test procedure and results

The development of experimental samples of the ignition units of laser pyroelectric sensors was a test for the reliability of operation at the JSC "Murom Instrument-Making Plant". The ignition unit was installed in a clamp (vise), after which a laser diode with an output power of 4 W, a wavelength of 808 nm, operating in a continuous mode was connected to the connector at the input end of the fiber. After that, the laser diode was switched on through the driver at the maximum power mode (q = 9.931⋅10 ³ W / cm ² , the operating current of the laser diode = 4200 mA).

Reliability tests have shown that the laser initiation scheme implemented in the design of the ignition unit of the pyroenergy sensor successfully ensures reliable operation of the initiating charge, and, consequently, of the entire pyroenergy sensor.

When determining the threshold operating mode of the source in the course of a series of experiments, the radiation power was decreased with a certain step until a response failure was obtained. The power was controlled by changing the operating current of the laser diode by the driver limb. The delay time was also recorded. When a failure occurs, the operating current of the diode can be compared to the output power density at the output end of the fiber. The dependence of the delay time for the initiation of the THPC charges on the power density at the output end of the optical fiber is shown in Fig. 4.

The value of the threshold power density for the initiation of the pressed charge of TNPC was obtained, equal to 4.7⋅10 ³ W / cm ³ .

Tests were carried out on the developed pressure in JSC "Murom Instrument-Making Plant". A pyroelectric laser sensor connected to a laser initiation system was installed in a manometric bomb with a piezoelectric pressure sensor. The laser diode was connected to a power supply. After a radiation pulse was applied using an oscilloscope connected to the sensor, a series of experiments was carried out. As a result, the curves of the triggering pressure of the laser pyroelectric sensor from the laser initiation system were obtained (Fig. 5). The response time (from the delivery of radiation to the beginning of the rise in the pressure curve) was obtained, equal to 1 ms, which is 10 times less than in the prototype.

Tests were carried out for the effect of elevated temperatures in JSC "Murom Instrument-Making Plant". In a heat chamber with a predetermined temperature of (200 ± 5) ° C, products were placed, which were kept in it for 2.5 minutes. Based on the results of the tests, it was concluded that the design of the pyroenergy sensor ensures the safety and performance of the product during and after exposure to a temperature of (200 ± 5) ° C for 2.5 minutes.

Initiation was carried out by direct action of radiation on the initiating charge of the TNPC without the use of focusing lenses and other optical elements. This scheme is distinguished by simplicity of implementation, minimum delay time, increased reliability, and minimum radiation power losses.

To ensure a high and constant value of the radiation power density, the ends of the optical fiber were polished on abrasive films with a grain size of 5, 1, 0.3 microns in the order of decreasing grain size.

High quality of polishing and small (less than 500 nm) end beating of optical fiber after processing of its ends by polishing ensures minimization of the delay time of initiation of charges of explosives and pyrocompositions, as well as its minimum spread.

The claimed device makes it possible to exclude accidental triggering of the initiation system from the influence of electromagnetic fields, random electric discharges, provides speed, minimum delay time, the ability to control the ignition delay time of the initiating charge of the pyroenergy sensor by controlling the radiation power density, minimum study power losses, the possibility of flexible adaptation of the laser initiation system for various requirements and tasks, as well as the ease of implementation of laser initiation of an explosive.

The claimed device meets the criteria of "novelty" and "industrial applicability". The design of the proposed laser pyroenergy sensor has been tested with a positive result at the Murom Instrument-Making Plant JSC.

Claims (3)

1. Pyroenergy sensor, in the body of which there is an ignition unit with an initiating charge in the recess of the block and a pyrotechnic charge in the cap, separated from the initiating charge by a compensating disk and a movable obturating cone resting on a grate, which has a nest with a transfer charge on the side of the pyrotechnic charge, and in an afterburner is mounted on the muzzle of the body, supporting the cap with a pyrotechnic charge, characterized in that a centering split bushing with an optical probe is installed in the block of the igniter unit, which is a rod with an internal channel in which an optical fiber is located, polished flush with the surface of the recess for the initiating charge and separated from it with an optical gasket. 2. Pyroenergy sensor according to claim 1, characterized in that an HCS-type optical fiber with a core diameter of 205 μm and a cladding diameter of 230 μm is used, and the core is made of glass, and the damper is made of polymer, polished on abrasive films with a grain size of 5, 1, 0, 3 μm in order of decreasing grain size. 3. Pyroelectric sensor according to claim 1, characterized in that the optical spacer is made of fluoroplastic.

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