RU2541619C2 - Safety mechanism of repeated cocking - Google Patents

Abstract

FIELD: weapons and ammunition.

SUBSTANCE: invention relates to military technology, namely the safety mechanisms used in pyrocartridges. The safety mechanism comprises a slider. The slider opens or closes the firing channel between the initiator and the charge. The slider is placed between the ends of two electromagnets. The slider has two cylindrical anchors. Each anchor enters into one of the electromagnets. The anchors enter into the electromagnets from the outer ends, which are fixed on the arms of the rotary stops. The second arms of the stops are preloaded by the springs to the slider. The stop, the anchor of which has a clearance with the end of the electromagnet, is engaged with the slider, preventing its possible movement. The stop, the anchor of which is in contact with the end of the second electromagnet without a gap or with a small gap, rests on the slider, without preventing its possible movement. On the slider the inclined planes are made to which the balls are preloaded by the springs.

EFFECT: providing resistance to mechanical impact and increasing in reliability.

2 cl, 3 dwg

Description

The invention relates to military equipment, in particular to safety mechanisms used in squibs, which are used in rocket technology for igniting solid propellant jet engines, gas generators, cutting off engine thrust, etc. These mechanisms can be used in various explosive devices cocked by an electric command.

Safety mechanisms increase the safety of the above products, but reduce their reliability due to the complexity of the design of the product. The use of safety mechanisms capable of repeatedly cocking and returning to the service (uninvolved) position when the appropriate command is issued allows increasing the reliability of the safety mechanism by repeatedly testing the cocking during its manufacture and during operation. At the same time, the security of complexes, for example, missile systems, in which the launch cancellation is possible after cocking the safety mechanisms in the squibs is possible, and accordingly, the safety mechanism must be returned to its official position.

Known fuse [1], in which in the official position the channel between the electric initiator and the output pyrotechnic charge is blocked by a rotary rotor made of a permanent magnet with diametrically positioned poles. The rotor has the ability to rotate around the axis and is placed inside the stator with a winding. In the official position, the rotor is held by the forces of attraction of the permanent magnet to the housing made of ferromagnetic material.

The stator has pole projections offset from the initial position of the rotor by 90 °.

To cock the stator winding, a current of a certain polarity is supplied and the rotor, interacting with the pole surfaces of the stator, rotates 90 °, orienting the hole in it coaxially with the electric initiator and charge. The rotor returns to its official position when the stator winding is de-energized under the action of forces arising from the interaction of the rotor permanent magnet with the ferromagnetic material of the housing. The rotation of the rotor and its fixing in the service position are ensured by the fact that in this position the gaps between the poles of the rotor and the housing are minimal and, accordingly, the attractive force between them has a maximum value.

The disadvantage of this safety mechanism is the need to supply voltage to the stator winding during the entire cocked position of the rotor. This circumstance complicates the use of these devices due to the limited capabilities of power sources on board the rocket, as well as because of the need to increase the size of the stator winding, to ensure its thermal stability during prolonged supply of current.

Known fuse [2], in which in the official position two holes with the ends of the detonating cords fixed to them are offset by about 90 ° relative to two electric detonators located in a rotary rotor, which can rotate inside the stator winding, moving from the service position to the cocked position and back to depending on the polarity of the voltage supplied to the stator winding.

The rotation of the rotor provides the force arising from the interaction of the magnetic fields of the stator and the permanent magnet diametrically mounted on the rotor.

In extreme positions, the rotor is fixed by two spring-loaded clamps located in the mechanism body and abutting their ends in the holes made on the side cylindrical surface of the rotor.

When turning, the rotor pushes the tabs out of the holes. In the final phase of rotation, the latches are recessed by springs into another pair of holes, fixing the rotor in this extreme position.

To limit the angle of rotation of the rotor on its lateral cylindrical surface, a groove is made and in the extreme positions the walls of this groove abut against a latch fixedly mounted in the mechanism body.

To prevent unauthorized cocking of the fuse from mechanical stresses, the rotor in the service position is additionally fixed with a safety pin, which is manually removed when the fuse is installed on the object or immediately before the start of the object.

The disadvantage of this mechanism is the limited resistance to mechanical stress and, as a consequence of this, the need to use safety checks. However, the use of checks provides resistance to mechanical stress only in official circulation until it is removed. This drawback is especially significant when using the mechanism in rocketry, since significant vibrational and shock overloads occur during rocket flight caused by the operation of engines and the operation of various pyrotechnic devices.

Insufficient resistance to mechanical stress does not allow to ensure high reliability and safety of the product. It is possible to increase resistance to mechanical influences of the device in question only by increasing the pressure force of the clamps on the rotor, but increasing this force is limited by the value of the rotor torque, which, in turn, is limited by the dimensions of the mechanism and the power mode of the stator winding.

The problem solved by the present invention is the creation of a safety mechanism of multiple cocking that meets the requirements for resistance to mechanical stress with high reliability.

The essence of the invention lies in the fact that the safety mechanism includes an engine that opens or closes in one of the two stable positions the fire channel between the initiator and the charge, while the engine is placed in a plane perpendicular to the longitudinal axis of the fire channel between the ends of two coaxially mounted electromagnets, and has two cylindrical anchors. Each anchor enters one of the electromagnets. From the external ends, the electromagnets include anchors that are mounted on the shoulders of the rotary stoppers. The second shoulders of the stoppers are spring-loaded to the engine. The stopper, the anchor of which has a gap with the end face of the electromagnet, engages with the engine, preventing its possible movement. The stopper, whose anchor is in contact with the end face of the second electromagnet without a gap (with a small gap), rests on the engine, without interfering with its possible movement. On the engine, inclined planes are made, to which the balls are pressed by springs, while the traction force of the electromagnet acting on the engine’s anchor exceeds the resistance of the balls only after the stopper has turned and it has no contact with the engine.

The task to increase the stability of the safety mechanism to mechanical influences is achieved due to the fact that when cocking or returning the safety mechanism to its original position, the corresponding armature of the engine and stopper move towards each other.

Consequently, for unauthorized cocking or returning the mechanism to a service position, inertia forces directed in opposite directions must act on the armature of the engine and stopper. Moreover, the amplitude and duration of these oppositely directed forces should be sufficient both to turn the stopper until it disengages from the engine, and to move the engine halfway.

Spring-loaded balls push the engine to its extreme position to ensure that the stopper rotates before the engine begins to move, which prevents it from jamming. Advance rotation of the stopper is facilitated by the fact that the electromagnetic force acting on the engine increases inversely with the square of the distance between the anchors of the engine and the stopper.

In addition to the above technical solutions that increase the stability of the safety mechanism to mechanical loads, conical shaped cavities are made at the ends of the engine anchors, and conical protrusions of the reciprocal shape are made at the ends of the stop anchors. Conical shape of the anchors allows to increase the area of the magnetic poles with a corresponding increase in the magnetic conductivity of the working air gaps without increasing the diameter of the anchors. In turn, an increase in the magnetic conductivity in the working air gap leads to a direct proportional increase in the tractive effort at the armature of the engine and the stoppers, which allows a corresponding increase in the moment created by the rotary spring to fix the stopper, and, consequently, to increase the resistance of the safety mechanism to mechanical stresses.

Figure 1-3 shows the design of the safety mechanism developed using the present invention.

The safety mechanism comprises a housing 1 with an engine 3 located in it, which, with its anchors 4, enters the cocking electromagnet 15 and return electromagnet 14. The cocking stopper 2 is pressed by a torsion spring (not shown) to the engine 3 and fixes it in the service (unbroken) position, and the return stop 6 is also pressed by its spring to the engine 3, but does not impede its movement. The engine 3 is pressed against the end of the return electromagnet 14 by balls 9 using springs 8, caps 11, plugs 7 and sleeves 10. To reduce friction, the armature 4 is placed in the bearings 5. In the service position, the hole D in the engine 3 is offset relative to the hole B connecting the electric igniter 13 with a pyrotechnic charge 12. With its right shoulder, the engine 3 interacts with the pushers of the microswitches (not shown), opening or closing their electric circuits to provide control of the position of the engine 3.

For cocking, voltage of any polarity is supplied (alternating voltage can be supplied) to cocking electromagnet 15, cocking stopper 2 rotates to overcome spring resistance, and its left shoulder disengages from engine 3 and does not prevent its possible movement. When the stopper 2 is rotated, its anchor 16 approaches the anchor 4, reducing the working air gap, and the electromagnetic force acting on the engine’s anchor increases and becomes sufficient for the engine 3 to squeeze the balls 9, which leads to the movement of the engine 3 to the cocked position. In this case, the return stopper 6 is spring pressed against the surface Г of the engine 3 and fixes it in the cocked position. In the middle of the engine’s stroke, the balls 9, passing from the opposite inclined surfaces of the engine 3, contribute to its movement and, at the end of the stroke, press the engine 3 to the cocking electromagnet 15.

After removing the voltage from the cocking electromagnet 15, the left shoulder of the cocking stopper 2 is spring-tightened against the stop in the protrusion of the engine 3, without interfering with its possible movement from the cocked position. In the cocked position, the hole D in the engine 3 is aligned with the hole B, thereby creating a channel connecting the electric igniter 13 with a charge 12. The engine 3 is returned to its service position similar to cocking, but the voltage is supplied to the return electromagnet 14.

Based on the proposed technical solution, a squib with a multiple cocking safety mechanism has been developed, which has high reliability and meets all the requirements for resistance to mechanical stress in operating conditions as part of rocket technology.

Information sources

1. US patent No. 3658009, CL. F42b 5/08; 102 / 70.2, 1972.

2. US Patent No. 5,279,226, cl. F42c 15/40; 102/254, 1994.

Claims (2)

1. The safety mechanism of multiple cocking, characterized in that it contains an engine that opens or closes the fire channel in one of two stable positions, while the engine is located between the ends of two coaxially mounted electromagnets and has two cylindrical anchors, each of which is included in one of electromagnets, and from the external ends of the electromagnets placed anchors mounted on the shoulders of the rotary stoppers, the second shoulders of which are spring-loaded to the engine, and the stopper, the anchor of which has a gap with the torus ohm of the electromagnet, engages with the engine, preventing its possible movement, and the stopper, the anchor of which is in contact with the end face of the electromagnet without a gap or with a small gap, rests on the engine without preventing its possible movement, while the engine has inclined planes to which the balls are spring loaded, and the traction created by the electromagnet at the engine’s anchor exceeds the resistance of the balls only after the stopper’s anchor approaches the engine’s anchor and the stopper disengages from the engine. 2. The safety mechanism according to claim 1, characterized in that the ends of the anchors of the engine have recesses of the conical shape, and the ends of the anchors of the stoppers have conical protrusions of the reciprocal form.

Images