RU2269736C2 - Method for enhancement of accuracy of fire of tank gun an tank gun - Google Patents

Abstract

FIELD: armament.

SUBSTANCE: the accuracy of barrel positioning is enhanced by placement of it in the guides with an increased supporting base. At a shot during motion of the shell in the barrel the resistance to the recoil is minimized, thus providing the symmetry of the recoil resistance forces relative to the longitudinal axis of the barrel. After the shell leaves the bore the recoil resistance is enhanced. The accuracy of positioning is restored during counterrecoil. The inner walls of the bore are coated by a wear-resistant heat-resistant layer, and the barrel is covered by a heat-shielding cover. The gun is provided with a neck fastened on the front part of the cradle. The front guide support is positioned in the cradle neck and made of the main and auxiliary rings. The diameter of the main supporting ring positioned closer to the muzzle end is less than the diameter of the auxiliary supporting ring. Cylindrical bearing and conical surfaces are made on the barrel. The cylindrical bearing surface is positioned for engagement with the main supporting ring, and its working length before the main supporting ring, and its working length before the main supporting ring corresponds to recoil length L of the barrel before the shell leaves the bore.

EFFECT: enhanced accuracy of fire.

4 cl, 4 dwg

Description

The invention relates to methods for improving the accuracy of the firing of guns, in particular tank guns, by preserving the geometry of their barrels from the influence of external and internal factors and maintaining the position of the axes of the barrels relative to the aiming line, as well as to barrel structures and their placement in the gun installation.

Known designs of guns containing a barrel with a breech mounted on a carriage and equipped with recoil devices [1].

This source describes the design of guns, methods for the manufacture of barrels and their hardening.

Known designs of guns, the trunks of which are installed in the guide cradles with a thermal gap [2]. The values of thermal gaps and the support base of the cradle (the distance between the front and rear bearings of the barrel in the cradle) determine the magnitude of uncontrolled angular deviations of the axis of the barrel.

An increased thermal gap and a reduced support base of the barrel in the cradle impair firing accuracy, and a reduced clearance can lead to jamming of the barrel in the guides. This problem is most relevant for tank guns firing on the move. Fluctuations in the barrel due to gaps in the cradle impair firing accuracy. This is a disadvantage of the known guns.

A device of tank guns 2A46 and 2A46-1 [3], having a barrel, bolt, cradle and recoil device, is known. Anti-recoil devices are located asymmetrically to the longitudinal axis of the gun, which creates a disturbing moment during the shot, leading to oscillations of the gun. In addition, the described recoil devices begin braking immediately after the start of the rollback of the barrel, while the projectile is moving along the barrel. It also negatively affects firing accuracy.

Modifications of the D-81 tank gun are known under the indices 2A26, 2A46 and 2A46M [4], which can be adopted as a prototype.

In guns 2A26 and 2A46, the barrel is placed in a cradle, which is a cylinder with two cylindrical inserts with a diametral clearance of 0.5 ... 0.8 mm, on which the barrel rests. The distance between the liners is limited by the size of the tower.

The drawback of the 2A26 and 2A46 guns is that due to thermal gaps and a relatively short base of the cradle guides, barrel vibrations occur during the movement of the tank, which leads to an increase in the dispersion of shells.

The 2A46M cannon has a front cylindrical insert (barrel support), and the barrel is supported by a breech on the rear support, with which the pipe is connected by a bayonet connection. Due to the transfer of the back support to the breech, the support base of the trunk in the cradle is increased.

The disadvantage of the 2A46M gun device is that the weakening of the bayonet connection of the pipe with the breech can lead to oscillations of its rear part relative to the front, i.e. also to barrel oscillations during tank movement.

A common drawback of the mentioned structures is that with a long pipe length (6 m), a significant share in the deterioration of the accuracy of the fire is introduced by the bending of the gun barrel. The bending of the barrel depends, first of all, on its rigidity, as well as on the features of heating the barrel during firing and its cooling mode. The uneven distribution of heat along the length and circumference of the barrel, as well as the unevenness of its cooling cause bending of the barrel and lead to loss of accuracy. For example, uneven cooling of the barrel heated by firing by rain led to the deviation of the shells from the target by 2 m or more at a distance of 2000 m. Therefore, the organization of the correct thermal regime inside and outside the barrel will reduce its bending.

It is known that when fired, the heat generated is distributed unevenly along the barrel. The most heated is the part of the barrel adjacent to the breech, and the muzzle is less heated. The rear most heated part of the trunk receives the most wear. To combat this, the inner surface of the barrel is covered with wear-resistant coatings [5].

The problem solved by the present invention is the creation of a method for increasing the accuracy of a tank gun shooting, taking into account the interrelated factors affecting the geometry of its barrel and maintaining the position of the barrel axis relative to the aiming line, as well as the adoption of a set of design measures that implement this method.

The problem is solved in that in order to reduce the influence of external and internal factors affecting the projectile during its movement along the bore, increase the accuracy of the positioning of the barrel.

To do this, the barrel is installed in rails of increased accuracy with an increased support base of the barrel in the cradle. At the same time, the forces of resistance to recoil are symmetrical and, prior to the projectile, are reduced to the minimum possible value.

At the same time, the heat generated during the firing is reflected from the inner walls of the bore, maintaining the high temperature of the powder gases.

For this, the inner walls of the barrel are covered with a heat-reflecting layer, which also must be wear-resistant at high temperatures, for example, chromium [5]. It is known that, in addition to increasing wear resistance, polished chrome coating has a higher reflective and heat-insulating ability compared to polished steel [6].

Chromium is suitable as a material for such a coating. The coating is polished, and then it acquires a spectral reflection coefficient Pm (λ) = 0.90 ... 0.92 in the infrared range. For comparison, we note that polished steel has a significantly worse reflectivity in the indicated temperature range. The spectral coefficient for it is Pm (λ) = 0.623 ... 0.853, and the higher the ambient temperature, the lower it is [6, 7].

Using the heat-reflecting properties of polished chromium, it is possible to reduce heat absorption in the breech of the barrel and redistribute heat throughout the barrel of the gun, which helps to reduce the bending of the barrel caused by the temperature gradient of its different parts.

Further, to reduce the uneven cooling of the heated barrel, for example, from the effects of rain, snow, wind, its surface is covered with a heat shield covering the barrel with a clearance sufficient for free circulation of the cooling working fluid, such as air.

Figure 1 shows a General view of the proposed gun, figure 2 shows the design of the guides, and figure 3, 4 shows a cross section of the gun. The proposed tank gun consists of a barrel 1 with a breech mounted in the guides. 2, 3, 4. Moreover, the front cylindrical guides 2 and 3 are installed in the neck 5, mounted on the front of the cradle 6 inside the armor mask 7. The rear guide 4 is located in the cradle 6. The front guide 2 is the main support, and the guide 3 is auxiliary. Both are made in the form of rings arranged sequentially one after another along the axis of the bore of the barrel 1. The barrel is provided with a cylindrical supporting surface 7 of length L, conjugated with the conical surface 8 of the barrel 1. The inner surface of the barrel 1 is covered with a wear-resistant heat-reflecting layer 9, and the outer surface is covered with a heat-protective casing 10, covering it with a gap.

The device operates as follows.

Before the shot, the barrel 1 with a cylindrical supporting surface 7 is mounted on the main guide 2 with increased accuracy.

The working length of the cylindrical bearing surface 7, interacting with the main (exact) guide bearing 2, is determined from the expression

where q is the weight of the projectile, kg,

ω is the weight of the charge, kg,

Q - the weight of the recoil parts of the gun, kg,

l is the relative path of the projectile along the bore, m,

and corresponds to the value of "free" rollback of barrel 1. The friction force in the guides reduces the calculated values by 3 ... 5% and is not taken into account. Thus, the value of L is sufficient so that for the entire time the projectile moves along the barrel 1, the last one moves all the time in the exact (main) guide support 2. After the projectile leaves the barrel 1, it makes no sense to maintain accurate positioning of the barrel, because this leads to excessive wear of the guide ring 2. Next, the cylindrical surface 7 of the barrel 1 comes out of contact with the support 2 and further rollback occurs along the auxiliary ring of the support 3 of less accuracy.

The applicant conducted comprehensive tests of the claimed product, which fully confirmed the claimed benefits and proved the possibility of industrial use of the product.

Information sources

1. B.A. Nadin, I.A. Skorik, V.M.Shegeron, Artillery, M .: DOSAAF, 1972. P. 91-115.

2. A.N. Latukhin, Modern artillery. M.: Military Publishing House of the Ministry of Defense of the USSR, 1970, pp. 228-233.

3. E.A. Kosyrev et al. Tanks, DOSAAF, Moscow: 1979, p. 76.

4. 125-mm tank guns 2A46 and 2A46-1, technical description and instruction manual. M .: Military publishing house of the Ministry of Defense of the USSR, 1979 (prototype).

5. Jane s Defense Weekly, 2003, 8 January, p.30, 105-mm smoothbore gun 105 SB.

6. L.Z. Krikunov, Guide to the basics of infrared technology. M .: Soviet Radio, 1978, pp. 37-40.

7. MMMoroshnikov, Theoretical Foundations of Optoelectronic Devices, L .: Mashinostroenie, 1977, pp. 256-258.

Claims (4)

1. A method of increasing the accuracy of shooting a tank gun, which consists in maintaining the geometry of its barrel from external factors and maintaining the position of the axis of the barrel relative to the line of sight, characterized in that they increase the accuracy of positioning the barrel by installing it in guides with an increased reference base, when fired during the movement of the projectile along the barrel reduces the recoil resistance to the minimum possible value, ensuring the symmetry of the recoil resistance forces relative to the longitudinal axis of the barrel, and along After the shell leaves the bore, they increase resistance to recoil, and the positioning accuracy is restored during rolling, while the bore of the bore is coated with a heat-reflecting layer that is wear-resistant at high temperatures, and the barrel is covered with a heat shield to protect it from environmental influences. 2. Tank gun containing a barrel with a breech, located in the front and rear guiding supports of the cradle and connected to it by recoil devices, characterized in that it is equipped with a neck mounted on the front of the cradle, while the front guide support is located in the neck of the cradle and made of the main and auxiliary rings arranged sequentially one after another along the axis of the bore, and the diameter of the main supporting ring located closer to the muzzle is less than the diameter of the auxiliary of the supporting ring, and on the barrel there is a cylindrical supporting surface and a conical surface conjugated with it, facing the top of the muzzle, while the cylindrical supporting surface is arranged to interact with the main supporting ring, and its working length in front of the main supporting ring corresponds to the rollback length L the barrel before the projectile, the inner surface of the barrel is coated with a heat-reflecting layer that is wear-resistant at high temperatures, and its outer surface is covered with a heat shield. 3. The tank gun according to claim 2, characterized in that the wear-resistant heat-reflecting layer is made with a thickness of 0.15 ... 0.30 mm in the form of a polished chrome coating. 4. Tank gun according to any one of paragraphs.2 and 3, characterized in that the inner surface is covered with a wear-resistant layer of 0.2 ... 0.4 barrel length from the breech side.

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