RU2333455C2 - Master device with torsion springs - Google Patents

Abstract

FIELD: weapons.

SUBSTANCE: invention refers to the master device of a pressure-exerting type for armour-piercing composite projectile and can be used for all types of guns with a shell of the present type in the ammunition load. The device consists of three sectors with cylindrical torsion springs situated in the landing cavity of the sectors. Following projection of a pressure-exerting type for armour-piercing composite projectile from the gun tube subject to the force of reaction of the torsion springs and increscent force of the air resistance, the process of the master device sectors separation begins. The process of the master device sectors separation with the torsion springs is characterised by a considerable dynamism, hereupon the force impact of the separating sectors onto the active part of the shell is exluded, and their hitting with the stabiliser tail-fun of the shell is exluded which influences positively on the fire efficiency of the armour-piercing composite projectile of the present type.

EFFECT: increase in fire efficiency of the armour-piercing composite projectiles.

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Description

The invention relates to a master device (WU) of the “clamping” type for armor-piercing sub-caliber projectile (BPS) and can be implemented as a WU BPS for all types of guns having this type of shells in the ammunition set.

It is known that the process of separating the HE sectors from the shell of the projectile significantly affects the amount of technical dispersion (accuracy, accuracy). Despite the relative short duration of this process, the mechanical and aerodynamic force interaction between the separated elements and the shell of the projectile can lead to the formation of significant trajectory changes. The overall picture of the separation of sectors is asymmetric and asynchronous, which is explained by the influence on the separation process of disturbances received by the projectile when moving along the gun’s bore and during the aftereffect of powder gases (GH).

The main force factors that cause the separation of the sectors of the “down” type HI are the pressure force of the oncoming air flow, while the pressure of the GHG satellite flow prevents the process of their separation in the aftereffect (≈10 m). All this, as well as a considerable extension in time, leads to a significant asymmetry in the separation of the HE sectors and, as a result, to additional trajectory disturbances of the BPS and, as a rule, leads to damage to the aerodynamic surfaces of the projectile located in its rear part. In addition, as the shooting tests showed, when separating the WU sectors, there were violations of the correctness of the flight of the BPS.

There is a design for a pallet of a feathered projectile moving along the bore of a rifled gun barrel [1], containing several arcuate sections, each section of the pallet is an arcuate rear covering end, a cylindrical middle part connected integrally with the front end, and an arcuate covering end connected to the middle part. At the front end of the section, a peripheral groove is made for the obturating ring inserted into the grooves of the pallet section. The ring prevents the gas from escaping from the pan during the launch of ammunition. However, this design has the following disadvantages: when the projectile leaves the rifled barrel of the gun, the drop-off pan has the same muzzle velocity as the projectile, which is unsafe for calculating the gun; the arched sections of the pallet that are separated during discharge create a risk of damage to the projectile stabilizer.

A known design of the leading device for a sub-caliber rocket projectile [2], consisting of three sectors, each of which is equipped with a spring mechanism that provides the most rapid separation of the sectors from the shell of the projectile after departure from the pipe and consisting of a coil spring with a pusher located in the seat of each sector offset from the center of mass of the sector. However, this design has the following disadvantages: the equality of the moments tilting the annular sector of the ring as a result of the action of the force of the powder gases will not always be observed, therefore, the separation pattern of the sectors will be asymmetric and asynchronous in nature and, as a result, will lead to additional trajectory disturbances of the armor-piercing-projectile shell, except In addition, when resetting sectors, there will be a danger of damage to the projectile stabilizer.

The objective of the invention is to eliminate the risk of damage to the stabilizer of the projectile by WU sectors, to ensure the fastest, synchronous separation of sectors from the BPS body after departure from the barrel channel and to prevent contact between the WU sectors and the active part at the time of separation.

This goal is achieved by the fact that in the detachable BPS master device, consisting of three sectors, inside each sector, at both edges perpendicular to the longitudinal axis of the projectile, a landing cavity is made into which a torsion coil spring is installed.

This design of the detachable master device provides reliable and synchronous reset of sectors when the projectile leaves the bore, without damage to the projectile stabilizer and eliminates the force impact of the sectors on the shell of the projectile.

In Fig.1 shows a General view of the detachable host device armor-piercing projectile, in Fig.2 - the device at the time of separation.

The active type master device shown in FIG. 1 consists of the following elements:

- three sectors (1);

- six landing cavities for cylindrical torsion springs (two inside the housing of each sector (2);

- three cylindrical torsion springs (3);

- O-ring (4).

Cylindrical torsion springs (3) in the cavities (2) are installed with the aim of reducing the time of the separation process, eliminating contact at the time of separation and eliminating the collision of sectors (1) with the tail (6) of the projectile (5).

The principle of the proposed WU, depicted in figure 2, is as follows. When the projectile (5) leaves the bore and the sectors (1) are released from the o-ring (4), even during the aftereffect of the powder gases, the reaction forces of the compressed cylindrical torsion springs (3) on the BPS sectors (1) begin to act, after which they begin symmetrically separated from the shell of the projectile (5) normal to it.

To justify the main parameters of the process of separating sectors of the VU with torsion springs, the choice of geometric dimensions and strength parameters of a cylindrical torsion spring, it is necessary to carry out a theoretical calculation of the process of functioning of the master device as a whole.

In this regard, it is advisable to carry out calculations in two stages:

1) Determination of the parameters for separating the sectors of the master device from the BPS enclosure.

2) Determination of the parameters of a cylindrical torsion spring for the BPS sector.

To determine the separation rate of the BPS sectors V _sec on the plot L ₀ L ₁ = λ (Fig.2) we use the theorem on the change in kinetic energy. In this section, the gravity force G = mg and the reaction of the elastic cylindrical torsion spring F _{pc are} applied to the BPS sector.

According to [1], the work of gravity when moving vertically upwards is

The elastic force of the spring, restoring its shape, is directed towards the movement of the BPS sector. The work of the variable elastic force on displacement L ₀ L ₁ = λ is determined by the formula from [3]

Based on this, we obtain the following equation for the movement of the BPS sector in the area L ₀ L ₁ :

since the initial speed of the BPS sector is V ₀ = 0, we obtain

where from

To determine the safe height Y _s to which the BLS sector rises, in order to exclude its collision with the plumage of the BPS stabilizer, we use equation (1) to move the sector in the area L ₀ L ₂ . Assuming that the initial velocity and the final velocity of the sector is equal to zero, equation (1) takes the form

Sum (5) consists of the work of the elastic force F _n on the displacement L ₀ L ₁ = λ and the work of gravity F on the displacement L ₀ L ₂ = λ + Y _c , i.e.

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from where

To determine the parameters of the spring mechanism, it is necessary to find the static spring force of the spring according to the following relationship:

where M ₂ is the working torque of the elastic force of the torsion spring,

r is the shoulder of the application of force to the sector.

To create a given value of the working torque M ₂ it is necessary to determine the main parameters of the torsion spring. First, we determine the stiffness of the spring, determined by the dependence

where M ₁ = (0.3 ÷ 0.5) M ₂ is the preliminary moment of elasticity of the torsion spring.

As a result of heating the projectile and its elements in the process of moving along the bore to a temperature above 473 K, it is necessary to select the appropriate steel (60С2) [4].

According to the method described in [4], we define the following spring parameters:

The number of working turns

where l is the deployed length of the spring;

D ₀ - the average diameter of the spring;

The extended spring length is determined

where E is the elastic modulus of the wire (table. [4]);

- момент инерции поперечного сечения;

- moment of inertia of the cross section;

- угол закручивания при максимальной деформации,

- twist angle at maximum deformation,

- предварительный угол закручивания;

- preliminary twist angle;

d is the diameter of the wire.

The diameter of the wire is determined by the dependence

where R _to - the coefficient of curvature of the coil;

[σ] is the allowable stress (tab. [4]).

Average spring diameter

Outside diameter of spring

Spring pitch

Spring height

The length of one hook l _{0 is} taken constructively. The total wire length is determined by

Rated maximum voltage

Spring weight

where ρ is the density of the metal.

To ensure the calculation of the parameters of the process of separating the sectors of the active wing of the active type, the choice of the geometrical dimensions of the springs and the seat in each sector, it is necessary to carry out a theoretical calculation of the functioning of the overall operation.

The numerical implementation of the considered method was carried out on a PC. Given the intra-ballistic characteristics of the artillery gun, the geometrical, mass characteristics of the projectile, as well as the initial data (working torque of the elastic force of the cylindrical torsion spring M ₂ , the working angle of rotation φ _p and the grade of spring-hot rolled steel 60С2А (60С2), У8А according to GOST 14959- 79 for a cylindrical torsion spring used in the WU sectors), we obtain at the output numerical values of the statistical elastic strength of the cylindrical torsion spring (separation force of the sectors), coefficient The rate of spring stiffness, the speed of separation of the sectors and the height at which the sector will rise. The program allows optimization of the geometric parameters of the spring and the seat for it in the sector. The main criterion for selecting the dimensions of the spring is to achieve the maximum value of the separation force of the statistical force of elasticity of the torsion spring.

As an example, to carry out the calculations of the VU parameters, a standard model of BPS of caliber 125 mm with "clamping" sectors was taken as an analog of the invention. Based on the calculations on a personal computer, a graphical dependence of the change in the pressure forces of powder gases and air resistance at the beginning of the aftereffect of the powder gases (Fig. 3), the dependence of the change in wire diameter, spring height, wire diameter, spring diameter internal and external on the specified force value (Fig. .4, 5), the dependence of the total wire length on the set value of the force (Fig.6), the dependence of the change in pressure forces of the powder gases, air resistance and torsion spring at the beginning of the period of the after-effects of powder ha call (Fig.7).

The analysis of the graphs in Fig. 3 and Fig. 7 allows us to conclude: the prevalence of the air resistance force taking into account the additional static force of the torsion spring over the pressure force of the powder gases occurs earlier (Fig. 7), which contributes to the early separation of sectors. In addition, using a torsion spring of a certain type, you can create a non-contact separation of sectors from the BPS at the right time for us.

With an increase in the set parameter of the torsion spring force, the height of the spring, the wire diameter, the spring diameter are internal (external), and also (the separation rate of sectors from the active part of the BPS), but the dimensions of the VU and the strength characteristics of its material are imposed on the geometric parameters of the spring. In addition, increasing the length of the coil spring leads to an increase in the height of the landing cavity for it in the sector, which, in turn, is limited by the geometric dimensions of the sector.

Thus, the proposed WU with torsion springs makes it possible to exclude the time of the force impact of the sectors on the active part when they are separated and eliminates their collision with the plumage of the BPS stabilizer, which may positively affect the accuracy of firing with this type of BPS. There is an opportunity to create a non-contact separation of sectors from the active part of the BPS at the right time.

Information sources

1. US patent 4326464, publ. 04/27/82, MKI F42B 13/15 - prototype.

2. RU 2176376 C1, publ. 11.21.2001, IPC 7 F42B 14/06 - analogue.

3. Yablonsky A.A. The course of theoretical mechanics. Part 2. M., 1977, 433 p.

4. Zapletokhin V.A. The design of parts of mechanical devices. Directory. - L .: Engineering, 1990, 669 p.

Claims (1)

The leading device armor-piercing-projectile projectile containing supporting ring sectors with a recess at the front end, characterized in that inside each sector along its edges perpendicular to the longitudinal axis of the projectile are made landing cavities in which cylindrical torsion springs are installed.

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