WO2022132005A1

WO2022132005A1 - Canister and method for distributing submunitions

Info

Publication number: WO2022132005A1
Application number: PCT/SE2021/051249
Authority: WO
Inventors: Thomas Pettersson
Original assignee: Bae Systems Bofors Ab
Priority date: 2020-12-18
Filing date: 2021-12-14
Publication date: 2022-06-23
Also published as: SE2000241A1

Abstract

The invention concerns a canister (1,1'), which is arranged so as to encompass at least one submunition (10), which is to be housed in a projectile (100), where the canister (1, 1') is outfitted with at least one air brake (2) and at least one rotation brake (4). The invention furthermore comprises a projectile and a method.

Description

Canister and method for distributing submunitions

TECHNICAL FIELD

[0001 ] The present patent application relates to a canister comprising submunitions, a projectile comprising canisters and a method for distributing submunitions by means of a canister.

BACKGROUND OF THE INVENTION, PROBLEM AREA AND STATE OF THE ART

[0002] When combating ground targets, such as combat vehicles and/or tanks, with indirect fire, such as with artillery, it is possible to make use of projectiles that include active components in order to achieve weapon effect against said ground targets. Examples of effect components include submunitions that are released from a projectile, such as an artillery projectile, that pass the ground targets. Submunitions are preferably outfitted with their own sensors, such as target systems, in order to detect any target objects in the effect area of the submunitions. The submunition preferably moves in a descending motion towards the ground after being released from the projectile. During the movement of the submunition towards the ground, the sensors arranged in the submunition can be used to detect ground targets, if any. Once a ground target has been detected, the submunition can position itself so as to allow the weapon effect to be directed towards the ground target, e.g. by means of a directed blast effect.

[0003] The submunition is arranged in a projectile, e.g. a carrier projectile, and exits the projectile at a position where target objects are determined to be present. There are various methods of separating the submunition from the projectile, where one method involves ejecting the submunition from the aft portion of the projectile once a protective plate/hood/tray is removed from the projectile. When the submunition exits the projectile, large forces will be acting on the submunition, meaning that it is preferable to house it inside some form of protective device, for example a canister, also termed a can or a container.

[0004] Examples of projectiles outfitted with canisters which hose submunitions for combating target objects are shown in patent specification US 5,760,330, which shows a projectile outfitted with submunitions, such as mines, housed inside a load carrier positioned on a rocket engine. The load carrier is arranged with a space, which also acts as the ogival/ogive on the projectile, where a parachute is arranged. When the load carrier is separated from the rocket engine, the load carrier exits the trajectory of the projectile, whereas the rocket engine, which is stabilized by fins, remains in the trajectory of the projectile. The load carrier ends up in an unstable path once it has been separated from the rocket engine, e.g. by means of a pyrotechnic charge. Once the rocket engine has passed, a parachute is released in the space arranged on the load carrier. The parachute dampens the fall speed of the load carrier as the load carrier falls towards the ground. The submunitions arranged in the load carrier are released from the load carrier by means of a pyrotechnic charge or as a result of the mass of the submunitions (gravity), whereupon the submunitions release a parachute and fall towards the ground.

[0005] The invention shown in US 5,760,330 differs from the invention described in the present patent application in that the canister is not housed in the projectile but rather makes up part of the projectile, and in that the submunitions are full-caliber submunitions.

[0006] Additional problems which the present invention seeks to solve will become apparent in connection with the following detailed description of the various embodiments. PURPOSE AND FEATURES OF THE INVENTION

[0007] The present invention shows an improved canister which is able to remove a submunition from a projectile in a manner which does not result in the submunition being unduly affected, and which places the submunition in a condition and/or a position which allows for further combating of ground targets.

[0008] The invention concerns a canister, which is arranged so as to encompass at least one submunition, which is housed in a projectile, where the canister is outfitted with at least one air brake and at least one rotation brake and at least one submunition is separated from the canister when the fall speed is less than 115 meters per second.

[0009] According to additional aspects for a canister, arranged so as to include at least one submunition housed in a projectile, the following applies: the air brake is a parachute the parachute is attached to the canister by means of a ball bearing.

[0010] the rotation brake consists of at least one brake flap which is arranged on the canister in a fold-out fashion.

[0011 ] The invention further consists of a projectile which utilizes canisters as per the above.

[0012] The invention further consists of a method for the distribution of submunitions arranged in a canister from a projectile, including the following method steps: i.) the canister, comprising at least one submunition, is separated from a projectile, ii.) the canister is braked by means of an air brake, iii.) the canister is braked by means of a rotation brake, iv.) at least one submunition is separated from the canister when the fall speed is less than 115 meters per second.

[0013] According to additional aspects for a method for distributing submunitions arranged in a canister from a projectile, the following applies: at least one submunition is separated from the canister when the rotational speed is less than 150 revolutions per minute. the air brake is a parachute which is unfolded once the canister has exited the projectile. the rotation brake is at least one brake flap which is unfolded once the canister has exited the projectile.

THE ADVANTAGES AND EFFECTS OF THE INVENTION

[0014] The advantage of the present invention is that the rotational speed and/or fall speed of a submunition can be reduced prior to the initiation of the combat phase of the submunition, as the submunition is falling towards the ground. By reducing the rotational speed and the falling speed to a speed which is suitable for the sensors arranged on the submunition, the functionality of the submunition is improved. The submunition is able to influence the rotational speed and/or the fall speed to some extent, by means of bearing surfaces arranged on the submunition. Since it is advantageous not to provide large bearing surfaces on the submunition, the rotational speed and/or fall speed cannot be lower than the rotational speed and fall speed inherent in the projectile, meaning that a canister is required for purposes of reducing the rotational speed and fall speed prior to the combat phase of the submunition.

LIST OF FIGURES [0015] The invention will be described below by reference to the figures that are included there:

Fig. 1 shows a schematic of a projectile arranged with a submunition housed in a canister, according to one embodiment of the invention.

Fig. 2 shows a schematic of a cannister according to one embodiment of the invention.

Fig. 3 shows an ejection process for a projectile according to one embodiment of the invention.

Fig. 4 shows an ejection process for a projectile according to an alternate embodiment of the invention.

DETAILED DESCRIPTION OF EMBODIMENT

[0016] Distribution of submunitions can e.g. be achieved by dropping submunitions directly from a carrier projectile/projectile. This can e.g. involve firing off the submunitions, or otherwise transporting them out of the projectile. This can e.g. be achieved by means of a pyrotechnic charge that creates a gas pressure that ejects the submunition out of the projectile.

[0017] The term submunition refers to an effect device comprising means for acting against a specific target and may also be referred to as the combat component, the bomb or the effect component.

[0018] The submunition is arranged so as to be separated from a fuselage, for example a carrier grenade, over a target area, whereas the submunition comprises an effect portion, a target detector and optionally a device which imbues the submunition with a rotation within which the target area may be scanned, for example, a helical pattern during the descending movement of the submunition towards the target area. Furthermore, the submunition may be outfitted with a parachute. [0019] By ensuring that the submunition is designed in a suitably aerodynamic manner, and that a braking area is present on a carrier surface arranged on the submunition, the submunition is able to acquire a suitable fall speed. In a first embodiment, the submunition lacks rotation. In an alternative embodiment, the braking area may provide a driving momentum around the spin axis, which imbues the submunition with a rotation. This is accomplished without the assistance of a parachute, which is advantageous since the parachute requires space. Within the available space inside a carrier grenade, additional space may instead be made available for the actual effect component.

[0020] Alternatively, the submunition can be arranged with a parachute, which provides the advantage that the braking effect and the rotation can be controlled with higher accuracy, albeit at the expense of the space of the parachute. With a parachute, the submunition, in a first embodiment, can be arranged without rotation or alternatively, the submunition, in a second embodiment, can be arranged with rotation.

[0021 ] The rocket grenade can e.g. have a caliber of 15.5 cm, which is fired off from an artillery piece in a ballistic trajectory towards a target area.

[0022] A projectile is arranged with at least one submunition, where the submunition is arranged in a canister. At a certain time or geographical point, or based on sensor information, the canister, arranged with at least one submunition, may be separated from the projectile. Sensor information may include information from sensors arranged in the projectile, for example optical, thermal or electromagnetic sensors arranged in the projectile, e.g. for the purpose of detecting vehicles in a certain position. When the sensor detects target objects, such as vehicles, the canister is separated from the projectile. Alternatively, the canister can be separated when a positioning device detects that the projectile is in a certain position. Furthermore, the canister can be separated from the projectile at a certain time when the projectile is determined to be in a position where submunitions housed in the canister are able to combat target objects on the ground. The position and time of the projectile can both be programmed prior to the projectile being fired off from the artillery piece, but can also be programmed by sending information to the projectile, e.g. by means of a radio.

[0023] One method of separating the canister from the projectile involves triggering a pyrotechnic charge that creates a gas pressure that ejects or otherwise moves the canister out of the projectile. The canister is preferably moved out of the aft portion of the projectile. A cover tray/aft portion can be arranged on the projectile. This aft portion can be removed prior to the canister being ejected out of the projectile, but can also be removed in connection with the canister being ejected out of the projectile. The cover tray/aft portion is preferably arranged so as to exit the trajectory of the projectile and thus not to stand in the way of the canister, which initially, having been separated from the projectile, travels in the trajectory of the projectile. If the cover tray/aft portion is removed, there is minimal risk of the cover tray/aft portion colliding with the canister, as the canister is braked after the canister is separated from the projectile. An embodiment which causes the cover tray/aft portion to be moved out of the trajectory of the projectile involves designing the cover tray/aft portion so that it includes a minor symmetrical imbalance as pertains to the circularity, which causes the cover tray/aft portion to be moved out of the projectile trajectory as a result of the high rotational speed of the projectile and thus of the cover tray/aft portion.

[0024] Once the canister has exited the projectile, an air brake may be deployed in order to reduce the speed of the canister. Examples of air brakes include various forms of parachutes, different forms of braking belts or wings/flaps. Furthermore, a rotation brake may be deployed in order to decrease the canister’s rotational speed. By reducing the rotational speed, the canister will continually position itself closer to a vertical position relative to the ground and the ground targets, as a result of a gravitational pull acting upon the submunition. When the speed and the rotational speed are damped to a level at which the submunition is able to be separated from the canister, a device such as a pyrotechnic charge is triggered in order to eject the submunition out of the canister. Since the submunition has higher weight, mass, and a smaller braking surface compared to the empty canister, which is outfitted with a folded-out parachute, the submunition is able to travel faster from the canister towards the ground surface. After exiting the canister, the submunition can fold/unfold brake surfaces and/or the parachute in order to create an increased brake surface.

[0025] Fig. 1 shows a projectile 100, also called a grenade or a carrier grenade, in an arrangement with a canister 1 , outfitted with at least one submunition 10. Furthermore, a pyrotechnic kit 102 is arranged in the projectile. The spark plug 104 of the projectile, preferably disposed in the tip or ogival of the projectile, includes control electronics for triggering the pyrotechnic charge 102. The spark plug 104 may include radio communication equipment 106 for receiving external radio communication and/or for transmitting information from the projectile 100. Triggering of the pyrotechnic kit 102 can e.g. take place at a certain programmed time, or otherwise be arranged in the spark plug before the projectile is fired off from a launching device or triggered/programmed/adapted during the movement of the projectile by means of the radio communication equipment 106. The pyrotechnic kit 102 can also be triggered at a certain position which may e.g. Be determined on the basis of a positioning system arranged in the projectile (for instance a satellite navigation system such as GPS/GLONASS, or an inertial navigation system), where the position is programmed or otherwise arranged in the spark plug prior to the projectile being fired off from a launching device or during the movement of the projectile by means of information received from the radio communication equipment 106. The pyrotechnic kit 102 can also be triggered by means of the spark plug 104 being outfitted with a sensor 108, such as a target finder, which detects a relevant ground target able to be combated by a submunition 10, and thus triggers the charge 102 in order to release the canister 1 housing the submunition 10. The canister 1 i protected by a rear portion 100, which may comprise a rocket engine and/or a base flow unit. The projectile 100 may be provided with shear pins or other devices for retaining the rear portion 110 of the projectile 100, and the rear portion 110 may be pushed away by the canister when the pyrotechnic charge has been triggered, thus pushing the canister 1 against the rear portion 110. Alternatively, the canister 1 may be removed by means of a different mechanical/pyrotechnic device which detaches the rear portion 110 prior to the pyrotechnic charge 102 being initiated and causes the canister 1 to be ejected out of the projectile 100. The rear portion 110 is designed to exit the trajectory of the projectile. The canister 1 is provided with an air brake 2, such as a parachute, attached to a rolling/siding bearing 3, such as a ball bearing. The canister is furthermore arranged with at least one rotation brake 4 in order to reduce the canister's rotation after the canister 1 exits the projectile 100. Projectile 100 should preferably be rotation-stabilized, which means that the canister 1 will be rotating at a high rotational speed once the canister 1 is separated from the projectile 100. A submunition 10 intended to act against a ground target should preferable have a rotational speed which exceeds the rotational speed for a rotation-stabilized projectile, meaning that the canister 1 decreases the rotation before the submunition 10 exits the canister 1. The rotation brake 4 may be a fold-out fin/flap/panel, which can e.g. be ejected radially from the canister 1 , or the rotation brake 4 may be a fin which is arranged so that it abuts the outer radius of the canister 1 , and is spring-loaded so that it is unfolded as the canister 1 exits the projectile 100.

[0026] Fig. 1 shows a canister 1 in a phase where the canister 1 with the folded- out air brake 2 has exited the projectile 100 and is falling towards the ground. The air brake 1 , which may be a parachute, is attached to the canister 1 by means of lines 5. The air brake 2 brakes the fall speed of the canister 1 . The canister 1 includes a space within which at least one submunition 10 has been arranged. The submunition 10 is retained in the cannister 1 , e.g. by means of shear pins which are broken in the event that the submunition 10 is ejected from the canister by means of a pyrotechnic charge. In an alternate embodiment, the submunition 10 is retained with a mechanical/electromechanical lock which when the lock opens and thus releases the submunition 10, so that the submunition 10 exits the canister 1 through falling out of the canister 1 , as the mass of the submunition 10 causes the submunition 10 to exit the canister 1. Projectile 100 has a high rotational speed, which means that the projectile is rotation-stabilized during its trajectory. Once canister 1 exits the projectile 100, it will continue to have a high rotational speed, since the projectile 100 had a high rotational speed 100 prior to the canister 1 exiting from the projectile. In order to prepare the combat phase of the submunition 10, the rotational speed of the canister 1 is decreased by means of unfolding rotation brakes 4 arranged on the canister 1. The rotation brakes 4 can e.g. be unfolded by means of braking flaps/rotation brakes being unfolded radially from the canister 1. The rotation brakes 4 can also be arranged so that the surface of the brake flap abuts the outer surface of the canister 1 and unfolds from the surface after the canister 1 has exited the projectile 100, e.g. by means of the brake flaps being spring- loaded and so that, when the projectile 100 no longer holds the canister 1 in the projectile 100, the brake flaps are released automatically and are locked in the unfolded position. In such cases, the brake flaps may be made from a material which is reshaped when the brake flaps abut the surface of the canister 1 , in order to conform to the shape of the canister 1 , but straightens and no longer retains the shape of the canister once the brake flaps unfold. The rotation brake/brake flap 4 can be partly situated in the rear portion of the canister 1 , with respect to the longitudinal direction of the canister, meaning the aft portion, as shown in figure 2, where the rear portion is the area where the canister is attached to the parachute, but can also be situated in the front portion of the canister, in figure 2 not shown. The fins, also termed rotation brake or brake flap, are in an unfolded position, radially outwards relative to the canister, and unfolded in the range of between 50% and 80% of the diameter of the canister. The axial length of the fins, chord, is in the range of 10% to 40% of the diameter of the canister. The number of fins preferably ranges from 4 to 8.

[0027] Fig. 3 shows an ejection process for a projectile 100 comprising a canister 1 outfitted with at least one submunition 10. Initially, while in position A, the projectile 100 exits an ejection device, such as an artillery piece. The projectile is preferably fired off in a manner which stabilizes its rotation. This is achieved by means of outfitting the projectile with a girdle, which causes the projectile to rotate by means of ribs arranged in the barrel of the ejection device. In a certain position in the trajectory, canister 1 is separated from projectile 100. In position B, an arrangement is shown which enables the canister 1 to exit projectile 100 by means of the rear portion 100 being detached from the projectile 100. The rear portion 100 can e.g. be separated by means of a mechanical lock which unlocks at a certain point, so that the rear portion is no longer attached to the projectile 100. In an alternative embodiment, the rear portion 110 may be separated by use of a pyrotechnic charge arranged between the projectile 100 and the rear portion 110, so that the rear portion 110 is separated from the projectile 100. In a third embodiment, the rear portion 110 can be arranged so that the rear portion exits the projectile 100 once a rocket engine/base flow unit has burned out. Once the rear portion 110 has exited the projectile 100, and is no longer in the trajectory of the projectile, the canister 1 can be separated from the projectile 100 as a result of the canister 1 , which is shown in position C, exiting the projectile 100 from the aft portion of the projectile 100. In a first embodiment, the canister 1 exits the projectile 100 as a result of a pyrotechnic charge arranged in the projectile 100 pressing on canister 1 or otherwise causing it to exit the projectile 100. In a second embodiment, an air brake/brake device, for example a parachute, arranged in or on the canister 1 , is unfolded, thus pulling the canister out of the projectile 100. Once the canister 1 exits the projectile 100, the air brake 2 slows down the speed of the canister, as shown in Figure D. An example of an air brake 2 is a parachute. Furthermore, the rotation of the canister 1 will be reduced by means of a rotation brake 4 arranged on the canister 1 , preferably in the rear portion of the canister, at the position where it is attached to the parachute. When the rotational speed is reduced so that the rotational speed is less than 150 revolutions per minute (rpm) and the fall speed is less than 115 meters per second (m/s), the submunition 10 is able to exit the canister 1 . In a first embodiment, the submunition exits the canister 1 as a result of a lock between the canister 1 and the submunition 10 being unlocked. The mass of the submunition then causes the submunition to exit the air-braked canister 1 . In an alternative second embodiment, the submunition 10 may be ejected out of the canister 1 by means of a pyrotechnic charge arranged between the canister 1 and the submunition 10. When the submunition 10 has exited the canister 1 , the submunition 10 will initiate a combat phase against ground targets, which are not described any further in the present application.

[0028] Fig. 4 shows an ejection process for a projectile 100 comprising a canister 1 ' which is outfitted with at least one submunition 10. Initially, while in position A, the projectile 100 exits an ejection device, such as an artillery piece. The projectile is preferably fired off in a manner which stabilizes its rotation. This is achieved through outfitting the projectile with a girdle which causes the projectile to rotate by means of ribs arranged in the barrel of the ejection device. In a certain position in the trajectory, canister 1 ' is separated from projectile 100. In position B, an arrangement is shown which enables the canister 1 ' to exit projectile 100 by means of the rear portion 100 being detached from the projectile 100. The rear portion 100 can e.g. be separated by means of a mechanical lock which unlocks at a certain point, so that the rear portion is no longer attached to the projectile 100. In an alternative embodiment, the rear portion 100 may be separated by use of a pyrotechnic charge arranged between the projectile 100 and the rear portion 100, so that the rear portion 110 is separated from the projectile 100. In a third embodiment, the rear portion 110 can be arranged so that the rear portion exits the projectile 100 once a rocket engine/base flow unit has burned out. Once the rear portion 110 has exited the projectile 100 and is no longer in the trajectory of the projectile, the canister 1 may be separated from the projectile 100 by the canister 1 which is shown in position C, exiting the projectile 100 from the aft portion of the projectile 100. In a first embodiment, the canister 1 ' exits the projectile 100 by means of a pyrotechnic charge arranged in the projectile 100 pressing on canister 1 or otherwise causing it to exit the projectile 100. In a second embodiment, an air brake/brake device, for example a parachute, arranged in or on the canister 1 ', is unfolded, thus pulling the canister out of the projectile 100. Once the canister 1 ' exits the projectile 100, the air brake 2 slows down the speed of the canister, as shown in Figure D. An example of an air brake 2 is a parachute. Furthermore, the rotation of the canister 1 will be reduced by means of a rotation brake 4 arranged on the canister 1 ', preferably in the front portion of the canister, at the position opposite to the attachment point to the parachute. When the rotational speed is reduced so that the rotational speed is less than 150 revolutions per minute (rpm) and the fall speed is less than 115 meters per second (m/s), the submunition 10 is able to exit the canister 1. In one embodiment, the submunition 10 exits the canister 1 ' by the unlocking of a locking mechanism retaining a lid 7, which causes the parachute 2 attached to lid 7 to be detached from the canister 1 '. The submunition 10 may e.g. be forced out of the canister 1 ' by means of a pyrotechnic charge, which is now missing an air brake. Potentially, subsequent/additional submunitions may be ejected from the canister 1 ', ideally with some delay, by means of a pyrotechnic charge arranged between the canister 1 and the submunition 10. A suitable delay between the exiting of the first submunition and a second submunition from the canister is ranges from 0.1 s to 0.5 s. Once the submunition 10 or the submunitions have exited the canister 1 ', the submunitions/submunitions will initiate a combat phase against ground targets, which are not described any further in the present application.

It is preferable to reduce the fall speed to less than 115 m/s and/or the rotational speed to less than 150 rpm to reduce the effect from the surrounding media on the submunition when the submunition is released form the canister. The submunition could include sensors, fins, actuators and/or other sensitive components that initially is protected when the submunition is arranged in the canister. When the submunition is released from the canister the rotational speed and/or the fall speed should be reduced to a level where the components of the submunition is not negatively affected.

ALTERNATIVE DESIGN TYPES

[0029] The invention is not limited to the types of design specifically shown, but can be varied in different ways within the framework of the claims.

[0030] For instance, it is clear that the number of projectiles, submunitions and canisters, along with the included elements and details, are to be adapted to the one or several weapons systems, platforms and other construction-related properties which are applicable in each individual case.

[0031 ] Furthermore, the invention is not limited to certain types of target objects, but can also be applied to other types of targets, such as surface targets, ground targets or air targets.

[0032] Furthermore, the invention encompasses all types of projectiles, including grenades, high-explosive shells, robots, missiles and rockets.

[0033] Furthermore, the invention is not limited to a certain number of projectiles or target objects, but can be adapted to the number of target objects or projectiles presently at issue.

Claims

1. Canister (1 , 1 '), arranged so that it encompasses at least one submunition (10) for purposes of being arranged in a projectile, (100), characterized in that the canister (1 , 1 ') is arranged with at least one air brake (2) and at least one rotation brake (4) and where at least one submunition is separated from the canister when the fall speed is less than 115 meters per second.

2. Canister according to claim 1 , characterized in that the air brake (2) is a parachute.

3. Canister according to claim 2, characterized in that the parachute is affixed to the canister (1 , 1 ') by means of a ball bearing.

4. Canister according to any of the preceding claims, characterized in that the rotation brake (4) consists of at least one brake flap which is arranged on the canister (1 , 1 ') in a manner which enables it to unfold.

5. Projectile (100) characterized in that at least one cannister (1 ) according to any of the preceding claims 1 -5 is included.

6. Method for distributing submunitions arranged in a canister from a projectile, characterized in that the following method steps are included: i.) the canister, comprising at least one submunition, is separated from a projectile, ii.) the canister is braked by means of an air brake, iii.) the canister is braked by means of a rotation brake, iv.) at least one submunition is separated from the canister when the fall speed is less than 115 meters per second.

7. Method for distributing submunitions from a projectile according to claim 6, characterized in that at least one submunition is separated from the canister when the rotational speed is less than 150 revolutions per minute.

8. Method for distributing submunitions from a projectile according to any of claims 6-7, characterized in that the air brake is a parachute which is unfolded once the canister has exited the projectile.

9. Method for distributing submunitions from a projectile according to any of claims 6-8, characterized in that the rotation brake is at least one brake flap which is unfolded once the canister has exited the projectile.