JP2017223385A - Cylindrical metal container for gun ammunition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylindrical metal container for gun ammunition in which the number of scattered fragments caused by explosion of the container when an external shock is applied or ammunition or the like in the container ignites at the time of irregular state or trouble is reduced to enable damage at surroundings to be restricted while holding handling characteristic or airtightness for ammunition under a normal state.SOLUTION: This invention relates to a cylindrical metal container for gun ammunition of which cylindrical part main body having a predetermined length in an axial direction is sealed by a bottom member and a lid member. The cylindrical part main body is made in such a way that a metal plate having a predetermined thickness is formed into a cylindrical shape while being connected at one straight linear welding part in parallel in an axial direction, and a tensile strength at the welded part is 0.3 to 0.7 times of a tensile strength of metal plate mother material constituting the container main body.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cylindrical metal container for artillery ammunition.

  A metal container for artillery ammunition (hereinafter sometimes simply referred to as a metal container or container) is hermetically sealed and contains one or more ammunition containing explosives and explosives that are explosives after manufacture. Built and functions to protect internal gunpowder during transport, storage and even shooting.

  As described in the following Patent Document 1, an ammunition container used for a projectile charge for an ammunition can pack and transport a plurality of charge charges loaded with fine granular projectiles. It is a metal container used when storing in an ammunition cabinet. When inserting the propellant into a chamber such as an enamel shell, the propellant is taken out from the ammunition container and used. In general, an ammunition container as a packing container used for a shooting gun for a cannon or an ammunition for a gun has a structure having a drop strength and airtightness of a certain level or more in consideration of operational aspects. In Patent Document 1, there is no description of the fragile portion of the ammunition container.

  Patent Document 2 below provides an ammunition container that can prevent the explosion of the container in the event of an emergency when the explosives are ignited inside the container and suppress the surrounding damage while maintaining the drop strength and airtightness at the normal time. In order to achieve this, an ammunition container having a bottomed cylindrical container main body and a lid for closing the opening of the container main body, the cylindrical portion of the container main body is spirally wound with a metal long plate. It is formed into a cylindrical shape with a joint extending in a spiral shape by joining both side edges of the tube, and a long hole extending in the axial direction is formed in the cylindrical portion so as to penetrate inside and outside. An ammunition container is disclosed, wherein the elongated hole is sealed with a sealing material, and the outer surface of the elongated hole and the sealing material is covered with a metal cover member. Yes.

  In Patent Document 3 below, when a propellant stored in response to impact, heat, or the like explodes, the storage container is destroyed at a predetermined weakened portion so that the opening area by destruction is as large as possible. A container for a propellant charge is disclosed that can effectively open the door and prevent further intense reactions from occurring, and can prevent scattering of fragments. The storage container disclosed in Patent Document 3 is a cylindrical body in which a spirally wound belt-shaped metal plate is welded and integrated, or is formed in a cylindrical shape in advance, and both end portions of the cylindrical body A container for a propellant charge comprising a bottom fragile member and a lid member, the cylindrical body having a helical fragile portion formed in a length direction on at least one of an inner peripheral surface and an outer peripheral surface. is there.

  In conventional ammunition containers, when an ammunition such as a projectile charged in the container is ignited by impact or heat, which is an external factor, a combustion reaction of the explosive occurs in the highly airtight ammunition container. If the pressure inside the container rises, the container itself will explode, causing a great deal of damage to the surroundings. Therefore, in Patent Documents 2 and 3, a metal container in which a long hole with inner and outer penetrating holes is drilled in the axial direction as a fragile portion or an opening in a cylindrical portion formed by spirally winding a long metal plate, or a spiral shape A metal container having a spiral fragile portion on a belt-like metal plate wound around is proposed. However, in these metal containers, when the cracks are increased in the container body due to the impact of the flying object colliding, the metal container along the open part increased simultaneously with the opening of the long hole when the internal gunpowder reacted and the internal pressure increased. There is a problem that the number of fragments increases due to the progress of destruction.

  In the following Patent Document 4, in an adjacent material, a joint portion and one non-joint portion are arranged in parallel with the longitudinal direction of the container, and when there are two or more non-joint portions, a plurality of layers are provided via a stacking ring. There is disclosed a metal container having a non-bonded portion, which is bonded with a silicone sealant or a neoprene sealant. Such a metal container is a metal container which can avoid an explosive reaction when an internal explosive, a propellant, or a pyrotechnic is stimulated by providing such a non-joining part. In the metal container described in Document 4, the non-joined part is opened by the pressure difference between the container internal pressure and the container external pressure, but no mention is made of the strength of the main body part and the welded part. Generally, the strength of the welded part is comparable to that of the main body, so when a crack generated in the container body due to the impact of the flying object hits the welded part, the crack propagates through the weld line and breaks up. There is a problem that it is not possible to suppress an increase in the number of

JP 2004-226031 A JP 2013-44454 A JP 2012-17935 A US Pat. No. 7,624,888

  In view of the above, the problem to be solved by the present invention is to maintain the handling and airtightness of ammunition during normal times, but also when an external impact or explosives inside a container ignite in an abnormal or emergency situation. Is to provide a cylindrical metal container for artillery ammunition that can reduce the number of fragments scattered by the rupture of the container and suppress surrounding damage.

  As a result of intensive studies and experiments to solve the above-mentioned problems, the present inventors have found that such problems can be solved by the following configuration, and have completed the present invention. That is, the present invention is as follows.

[1] A cylindrical metal container for artillery ammunition in which a cylindrical body having a predetermined length in the axial direction is sealed by a bottom member and a lid member, and the cylindrical body is a straight line parallel to the axial direction The metal plate having a predetermined thickness is formed in a cylindrical shape by being joined at the welded portion, and the tensile strength of the welded portion is the tensile strength of the metal plate base material constituting the container body The cylindrical metal container for artillery ammunition, characterized in that the ratio is 0.3 to 0.7 times.
[2] The cylindrical metal container for artillery ammunition according to [1], wherein the weld is formed by partial penetration welding, stepping stone welding, or spot welding.
[3] Tensile strength of the weld is 0.3 to 0.5 times the tensile strength of the metal plate base material constituting the container body. Cylindrical metal container.

  The cylindrical metal container for artillery ammunition according to the present invention retains the handling and airtightness of ammunition at normal times, but in the event of an abnormality or emergency, when external impacts or explosives inside the container ignite It is possible to reduce the number of fragments scattered due to the rupture of the container and suppress surrounding damage.

It is a schematic diagram of the cylindrical metal container for artillery ammunition of this embodiment. It is a schematic diagram of the partial penetration welding which has a tensile strength lower than the tensile strength of the cylindrical part main body base material of this embodiment. It is a schematic diagram of the stepping stone welding which has a tensile strength lower than the tensile strength of the cylindrical part main body base material of this embodiment. It is a schematic diagram of the spot welding which has a tensile strength lower than the tensile strength of the cylindrical part main body base material of this embodiment. It is a schematic diagram of the complete penetration welding which has the tensile strength equivalent to or higher than the tensile strength of the cylindrical part main body of this embodiment. It is a schematic diagram of a crack progress when a crack contacts a weld line having a tensile strength lower than the tensile strength of the cylindrical part main body of the present embodiment. It is a schematic diagram of a crack progress when a crack contacts a weld line having a tensile strength equal to or higher than the tensile strength of the cylindrical body main body of the present embodiment. 2 is a schematic diagram of a shooting sensitivity test of Examples 1 and 2. FIG.

Hereinafter, embodiments of the present invention will be described in detail.
As shown in FIG. 1, the metal container for ammunition of this embodiment has a lid member 3 and a bottom member 4 in a cylindrical metal container main body 1 in the axial direction of the cylindrical container main body 1 from the base material of the container main body. Also, it is composed of one linear welded portion (weld line) 2 parallel to the axial direction of the cylindrical portion main body with reduced tensile strength. There is also a structure in which a reinforcing ring 5 is inserted in the container main body 1 between the lid member 3 and the bottom member 4 to reinforce the container. In some cases, the bottom member 4 is not provided and the lid member 3 is provided in two places. The lid member 3, the bottom member 4, and the reinforcing ring 5 are preferably made of metal, and the material is not particularly limited.

  If necessary, for example, a seal material may be applied to a non-welded portion represented by 12 in FIGS. 2 and 4 and 12a in FIG. Examples of the sealing material include general adhesives, caulking materials, solders, rubber materials, and the like.

Welding with a tensile strength lower than that of the base material of the container body, that is, welding of a welded portion having a tensile strength lower than that of the base material of the cylindrical part is partial penetration welding described in the welding manual. It can be stepping stone welding, spot welding, etc., and is a welding in which a non-welded part is left in the joint part of the container body.
The partial penetration welding refers to the welding of the butt section shown in FIG. 2, which does not cover the entire area of the base metal in the plate thickness direction, that is, when the butt section 10 of the metal container main body is welded. The welding is performed at the welded portion 11 while leaving the non-welded portion 12 in part.

  Further, stepping stone welding, also referred to as skip welding, is welding in which, when welding the butt portion 10 of the metal container body base material, welding is performed while being divided into certain sections during welding, as shown in FIG. And the non-welded portions 12a are alternately welded. This welding method can make the deformation and residual stress most uniform. It is preferable to have both non-welded portions of the non-welded portion 12a existing in the welding direction and the non-welded portion 12b in the base material thickness direction of the butt portion 10 in order to induce the progress of cracks.

  In addition, spot welding is a method in which a current is passed while pressing the butted portion 10 of the base metal container body base material superimposed as shown in FIG. 4 with an electrode, and the metal is melted using the electric resistance heat, It is welding which joins so that the welding part 11 and the non-welding part 12 may become alternate.

  In order to prevent the central portion of the container from opening due to an unexpected drop impact, it is preferable to weld at least three or more of the butt portions in stepping stone welding, and it is preferable to perform spot welding continuously in spot welding.

  For these welding methods, welding that does not lower the tensile strength than the container body, that is, welding of a welded portion having a tensile strength equal to or higher than the tensile strength of the base material of the cylindrical body is described in the welding manual. It is a complete penetration welding as described, and as shown in FIG. 5, a welding in which the weld metal is melted over the entire thickness of the base metal in the butt welding. The entire cross section of the butt portion 10 of the metal container main body is completely integrated by welding line 11 and welded. Generally, the tensile strength of the welded portion is considered to be equal to or higher than the tensile strength of the base material. The efficiency (= welded joint strength ÷ base material strength) can be regarded as 100%.

In this specification, the test method of tensile strength refers to JIS Z 2241. For example, the tensile strength of the hot rolled mild steel strip SPHC base material is 270 N / mm ² or more, and the tensile strength of the general structural carbon steel pipe STK400 base material is 400 N / mm ² or more. In this specification, welding with a lower tensile strength than the base metal described above means that the weld surface has a non-welded portion and the joint area is lowered to reduce the tensile strength of the welded portion in the axial direction of the cylindrical container. Welding reduced to 0.3 to 0.7 times the tensile strength of the base metal per length, preferably welding reduced to 0.3 to 0.5 times. As described above, partial penetration welding, stepping stone welding, and spot welding can be used alone or in combination as welding with a lower tensile strength than the base metal.

  The cylindrical metal container for artillery ammunition of this embodiment has one linear welded part (weld line) parallel to the axial direction of the cylindrical part main body, which has a lower tensile strength than the container main body base material. As shown in FIG. 6, the crack propagation direction is guided along the weld line, and both the function of suppressing the increase in the number of fragments and the function of reducing the opening pressure of the container are exhibited. It is possible to exhibit both suppression of crack propagation due to impact of a flying object and subsequent suppression of pressure increase due to reaction of internal explosives.

  In a conventional metal container for ammunition that has a helical weld line and a fragile part in the container body, when a bullet or high-speed debris collides with the container at a high speed of several hundred m / s to over 1000 m / s, A shock wave is generated at the location where the projectiles of bullets and high-speed debris collide and penetrate, and cracks are generated radially in the container. Furthermore, when the shock energy triggers and the gunpowder in the container starts to react and starts to burn, the pressure inside the container rises rapidly, stress is applied to the metal base material, cracks develop, and at the same time the pressure rises due to the gas burning the gunpowder. The spiral weakened part opens and opens so that an open piece that is much longer than the length of the container circulates around the container. Such cracks propagate into long open pieces that were in a spiral, resulting in an increase in the number of debris generated when the body container is broken.

  In order to avoid such an increase in the number of fragments, the container body according to the present embodiment has a linear shape parallel to the axial direction of the cylindrical container, instead of providing a helical weld line or a weakened portion on the container body. A welded portion having a tensile strength lower than that of the cylindrical container main body is provided. By using partial penetration welding, stepping stone welding, spot welding, etc. as welding with reduced tensile strength of the welded part, the gunpowder inside the container is protected from rainwater etc. in normal times, but in abnormal or emergency situations There is no progress of cracks generated in the container due to the impact of a high-speed flying object from the outside, and there is an effect that the number of fragments generated when the internal explosive is released when it reacts and burns is reduced. .

Inside the container of this embodiment, explosives, for example, one or a plurality of ammunition, for example, a propellant, are usually housed and sealed (not shown).
The burning rate of explosives, especially propellants, has the property of increasing in proportion to the power of 0.6 to 1.2. When the sealed internal explosives start burning, the internal pressure rises due to the combustion gas. The increased pressure further increases the combustion rate, and the reaction rapidly starts to explosive reaction within a short time. Therefore, in a sealed metal container for ammunition, there is a risk that great damage will occur in the event of an abnormality.
For example, when a high-speed flying object collides with a metal container for ammunition from the outside and the internal gunpowder reacts and burns due to the impact of an abnormality or the heat from an external fire, the container that can not withstand the rise in internal pressure explodes. There is a risk of serious damage.

As shown in FIG. 6, the metal container for ammunition of the present embodiment has a stress 21 acting on the metal container body base material 10 and the progress of the crack 20 contacts the welded portion 11. Also, by applying welding with reduced tensile strength, the crack propagation direction 22 is guided toward the welded portion, and the welded portion with reduced strength in the axial direction of the container is opened, so the number of fragments of the container body base material is reduced. However, the internal pressure can be released safely.
On the other hand, in a metal container joined by full penetration welding that does not reduce the strength, as shown in Fig. 7, the welded portion (weld line) has the same tensile strength as the container body base material. Even if 21 works and the progress of the crack 20 comes into contact with the weld 11, the direction 22 of the crack must pass through the weld 11 to induce the progress of the crack in the direction of the weld (weld line). The internal pressure of the container starts to be released from the crack, and the number of fragments increases explosively, making it impossible to safely release the internal pressure.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.
[Example 1]
As shown in FIG. 8, in a test specimen 30 of a metal container having a weld line 2 by partial penetration welding parallel to the axial direction of the metal container, a projectile charge 15 kg comprising a triple base propellant and a burnout container is provided. Housed. The cylindrical metal container had a main body length of 1010 mm, an outer diameter of 165 mm, and a thickness of 2.3 mm. The weld line was also 1010 mm, the same as the main body length, and the lid member 3 and the bottom member 4 were welded. The material of the metal container body was SPHC JISG3131 standard.
The welded part was partly welded at 1.6 mm, 0.7 times the thickness of the main body of 2.3 mm. The tensile strength of the welded part was 0.7 times the tensile strength of the main body base material.

The fire sensitivity test of this metal container was conducted according to STANAG 4241 (Bullet Impact Test). Stand up the metal container containing the gunpowder and fix the welded part by turning 90 degrees to the right from the direction of the bullet's incidence, and fire 12.7mm armor-piercing bullets from the position 30m away to the test specimen 30 with the gun 31. did. The bullet speed was 850m / s.
The bullet hit the center of the container and penetrated the container and the explosive, and the state in which the internal explosive burned and the metal container was torn was photographed with a high-speed camera 32 and observed.
As a result of observation with a high-speed camera, the bullet penetrates into the metal container, and at the same time, white smoke blows out from the front and rear through holes. Scattered from the area, the open area was surrounded by flames.
When the container was inspected after the combustion had subsided, the welded part of the main body was widely open, but there were no broken pieces of the container, and there was no scattering of the lid. Therefore, the number of broken pieces was counted as only one.

[Example 2]
As shown in FIG. 8, 15 kg of a projectile charge consisting of a triple base propellant and a burnout container was prepared in a test specimen 30 of a metal container having a welding line 2 formed by stepping stone welding that entered the axial direction of the metal container. . The cylindrical metal container had a main body length of 1010 mm, an outer diameter of 165 mm, and a thickness of 2.3 mm. The butt portion having the weld line is also 1010 mm, which is the same as the main body length, and the lid member 3 and the bottom member 4 are welded. The material of the metal container body was SPHC JISG3131 standard.
The welded part was a partly-penetrating stepping stone weld with a thickness of 1.6 mm, 0.7 times the thickness of the main body of 2.3 mm. The stepping stones were welded at both ends to 10 places at a pitch of 35 mm of non-welded part to 60 mm of welded part. The tensile strength of the weld was 0.45 times the tensile strength of the main body base material.
The fire sensitivity test of this metal container was conducted according to STANAG 4241 (Bullet Impact Test).
The metal container containing the gunpowder stood up and the welded part was fixed by shaking 90 degrees to the right from the direction of the bullet's incidence. . The bullet speed was 850m / s.
The bullet hit the center of the container and penetrated the container and the explosive, and the state in which the internal explosive burned and the metal container was torn was photographed with a high-speed camera 32 and observed.
As a result of observation with a high-speed camera, the bullet penetrates into the metal container, and at the same time, white smoke blows out from the two through holes in the front and rear, and then turns into a fierce flame, and the weld is opened and the explosive is burned and opened. The area around the open area was shrouded in flames.
When the container was inspected after the combustion had subsided, the welded part of the main body was widely open, but there were no broken pieces of the container, and there was no scattering of the lid. Therefore, the number of broken pieces was counted as only one.

[Comparative Example 1]
Prepare a 15 kg projectile charge consisting of a triple-base propellant and a burnout container in the test specimen 30 of a metal container with a weld 33 that does not reduce the strength and the main body by full penetration welding parallel to the axial direction of the metal container did. The cylindrical metal container had a main body length of 1010 mm, an outer diameter of 165 mm, and a thickness of 2.3 mm. The weld line was also 1010 mm, the same as the length of the main body, and the lid member 3 and the bottom member 4 were welded. The material of the metal container body was SPHC JISG3131 standard.
The weld was a full penetration weld at 2.3mm, the same as the body thickness of 2.3mm. The tensile strength of the weld was the same as the tensile strength of the main body base material.
The fire sensitivity test of this metal container was conducted according to STANAG 4241 (Bullet Impact Test). The metal container containing the gunpowder stood up and the welded part was fixed by shaking 90 degrees to the right from the direction of the bullet's incidence. A 12.7mm armor shell was fired from the position 30m away to the test specimen 30 with a gun 31 in a single shot. . The bullet speed was 850m / s.
The bullet hit the center of the container and penetrated the container and the explosive, and the situation where the internal explosive burned and the metal container was torn was photographed and observed with the high-speed camera 32.
As a result of observation by the high-speed camera, bullets penetrate the metal container and at the same time, white smoke blows out from the two front and rear through holes and turns into a fierce flame, the container opens explosively and the explosive burns and scatters to the entire periphery. The surroundings were wrapped in flames.
When the container was inspected after the combustion had subsided, the container itself was severely damaged as fragments, and the lid and fragments were scattered. The number of fragments was counted as 7 large and small, including the lid.

[Comparative Example 2]
In order to compare the container of this embodiment having a linear welded portion parallel to the axial direction of the cylindrical main body container and the container welded and joined in a spiral shape of the prior art, the partial penetration of Example 1 A linear cut having the same tensile strength as that of welding was applied to the helically welded and joined metal container. The helically welded and joined metal container had a main body length of 1010 mm, an outer diameter of 165 mm, and a thickness of 2.3 mm. The weld line was also 1010 mm, the same as the length of the main body, and the lid member 3 and the bottom member 4 were welded. The material of the metal container body was SPHC JISG3131 standard. Instead of the welded portion, the metal container body welded and joined in a spiral shape is parallel to the axial direction of the cylindrical body container and has a 1010 mm length (perforated part (non-joined part)). ) And non-perforated part (joint part)), and the pitch of the joint part and non-joined part (length of perforated part and non-perforated part) so that the tensile strength of the cut is 0.7 times the tensile strength of the base metal ) Was adjusted by laser processing.
For the container having the spiral joint in Comparative Example 2, the tensile strength of the cut was measured instead of the spiral weld. Since the container body is provided with a weak part, the number of fragments after the container breakage was only two compared to Comparative Example 1, but there was a weak part in the spiral welded joint, which occurred in the metal can when the bullet penetrated As a result, the number of fragments increased from Example 1.

  The cylindrical metal container for artillery ammunition of the present invention retains the handling and airtightness of ammunition during normal times, but when the explosives inside the container ignite in an abnormal or emergency situation, Since the number of splashes can be reduced and surrounding damage can be suppressed, explosives can be safely transported, stored and operated, and can be suitably used as a shell for ammunition.

1 Metal container body
2 Welded part with tensile strength lower than the tensile strength of the cylindrical base material
3 Lid member
4 Bottom member
5 Reinforcement ring
10 Metal container body base material butt
11 Welded part
12 Non-welded part
12a Unwelded part in the welding line direction of stepping stone welding
12b Non-welded part in the thickness direction of base metal in stepping stone welding
20 crack
21 Stress
22 Crack propagation direction
30 test specimens
31 gun
32 high speed camera

Claims (3)

  A cylindrical metal container for artillery ammunition in which a cylindrical body having a predetermined length in the axial direction is sealed by a bottom member and a lid member, and the cylindrical body is a single linear weld parallel to the axial direction The metal plate having a predetermined thickness is formed in a cylindrical shape by being joined at the portion, and the tensile strength of the welded portion is 0. 0 of the tensile strength of the metal plate base material constituting the container body. The cylindrical metal container for artillery ammunition characterized by being 3 to 0.7 times.   The cylindrical metal container for artillery ammunition according to claim 1, wherein the weld is formed by partial penetration welding, stepping stone welding, or spot welding.   The cylindrical metal container for artillery ammunition of Claim 1 or 2 whose tensile strength of the said welding part is 0.3 to 0.5 time the tensile strength of the metal plate base material which comprises the said container main body.