JPS62248999A - Accelerator for projectile by electrically heated plasma - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrically heated plasma projectile accelerator, and more particularly to an apparatus for accelerating a projectile using electrically heated plasma. and the first electrode is disposed coaxially within a closed portion of the pipe that is closed on one side;
The second electrode is then designed as an annular electrode and relates to a device for accelerating the projectile present in the pipe by means of an electrically heated plasma.

[Conventional technology]

A projectile in a metal pipe can be accelerated at high speed using electrically heated plasma (Gold Thetaine S, A, etc. Regarding research and development of plasma jet mass accelerator as a device for impact separation) Final Report: GT-Equipment, Alexandria, VA, USA, Coytrak) DE-ACO5-81-ER10846, 19
(see May 1984).

In this known device, plasma radiation is generated in a narrow capillary of insulating material and acts on the base of the projectile. The contact between the gas discharge and the capillary wall drives the insulating material and heats the plasma. As a result, plasma radiation is generated from the capillary opening.

A disadvantage of this known device is that the capillary section of the accelerator is subject to great wear, especially due to material vaporization and heating processes.

Therefore, the pipes of applicable weapons operating on this principle must be replaced very often. This is especially true if the weapon has to be used to fire one shot at a time.

[Problem that the invention seeks to solve]

It is therefore an object of the invention to improve a device of the type mentioned at the outset, so that even during long, continuous firing shots, the corresponding pipe sections are exposed to less wear.

[Means for solving problems]

In order to achieve the above object, the present invention employs a structure in which all parts exposed to severe wear, including both electrodes, can be easily replaced.

[Effect]

The invention therefore essentially provides that the plasma propagation is no longer introduced by a part of the accelerator itself, as was the case in one known device, but that both the introduction of the gas discharge and the subsequent heating process are separate parts that can be easily replaced. It is constructed by being carried out within a body unit and the projectile is also provided within this unit. Preferably, therefore, not only the projectile but also the entire cartridge is fed into the pipe in each case.

〔Example〕

Further advantages of the invention will be explained in more detail below using the exemplary embodiments shown in the drawings.

In FIG. 6, the known accelerator device is shown once again, as described in detail in the report by Goldseetine et al. cited at the outset.

In FIG. 6, the reference numeral 1 indicates a pipe that is closed on one side, and a first electrode 2 is installed at the base of the tube on the closed side. The second electrode (annular electrode) 3 is connected to the first electrode 2 via a voltage source 4 and a switch. A plasma chamber designated by 6 is delimited within the nozzle 1 by two electrodes 2 and 3, the area of the annular electrode 3 of this plasma chamber 6 being initially closed off by the projectile 7 to be accelerated.

After closing the switch 5 an arc is ignited between electrodes 2 and 3 and the projectile 7 is accelerated by the pressure of the arc plasma.

As already mentioned at the outset, this device has the disadvantage that the part of the mother plate forming the plasma chamber is exposed to very severe wear due to material vaporization and heating processes. The plasma cannon is supplied with not only the projectile 7 but also all parts exposed to severe wear, including the electrodes, in the form of a cartridge.

Next, the function of the cartridge 8 shown in FIG. 1 and then in relation to the cannon (FIG. 2) will be explained in detail.

The cartridge 8 essentially consists of a projectile 80, a jacket 81 surrounding the projectile, a second electrode 82 designed as a contact ring, and a first electrode 83 designed as a contact piece. The first electrode 83 and the second electrode 82 are separated by an insulating piece 84. Furthermore, a thin contact plate ring 85 is provided on the front side of the second electrode 82, and a thin contact plate ring 86 is provided on the rear side.

On the side of the first electrode 83 facing away from the projectile 80 a contact laminate disc 87 is provided. A gap-shaped discharge chamber 88 is provided between the projectile 80 and the first electrode 83.

Jacket 81 is preferably formed from a combustible and volatile material, such as polyethylene, and insulator 84 is formed from polycarbonate. In this case, the material that is easily vaporized is a substance that decomposes into molecules (gas) having a lower molecular weight (molecular weight <30) under the action of arc discharge.

Aluminum was used as the material for electrodes 82 and 83 in the following embodiments.

FIG. 2 shows how the cartridge 8 is arranged within the plasma cannon. Parts that are not relevant to the invention, such as the tail plug, are shown only schematically. What is designated by the reference numeral 9 is a portion of the pipe 90 on the closed side. In the closed chamber, contact between the inner conductor 92 and the first electrode 83 takes place via the contact sheet disc 87 . The outer conductor 93 is accordingly connected to the annular electrode 82 via a contact plate ring 86 .

The contact members 85, 86 and 87 of the cartridge are pressed against the pipe 90 and the coaxial first electrode by the pressure of the base piece 91.

A resilient silicon cartridge seal 97 is provided between the insulating means 94 and the insulating piece 84 for electrical sealing.

In order to carry out the acceleration process, the inner conductor 92 and the outer conductor 9
A voltage is applied between 3 and 3. Then, the first electrode 83
The acceleration step is introduced by a gas discharge formed in a narrow gap 88 between the and coaxial electrodes 82 and indicated at 96 in FIG. From the outer electrode 93 to the contact thin plate 86, the annular electrode 82, the gas discharge 96, the coaxial inner electrode &
During the rapid rise of the current i flowing through 83 and the contact laminated disc 87 to the inner conductor, material is evaporated and heated primarily in the vertical foot of the hot arc.

Furthermore, the close contact between the marks and the walls of the gap 88 causes other materials to be vaporized.

The pressure generated at this time drives the projectile 80 toward the end of the pipe.

A plasma is created within the combustion chamber that grows behind the projectile 80 during acceleration. This plasma is formed by a shank that conducts the current in the axis of the accelerator (if a plastic jacket 81 is used) and a case that is pressed against the jacket 81 by the force of the resulting current. The close contact of the plasma case with the jacket 81 vaporizes the surface of the jacket, thereby feeding the plasma with other materials.

FIG. 3 shows another embodiment according to the invention. In this case, parts that are the same as in FIG. 1 are provided with the same reference symbols. In contrast to FIG. 1, in this embodiment the projectile 80 is combined with the jacket 81 and the electrodes 82.83 with the contact plates 85.degree.

This division into separate component units makes it possible to insert first the projectile with the jacket 81 and, in the next part, the unit consisting of the electrodes 82, 83 and the insulating strips 84 into the cannon bore. Can be done. This division of the load into two temporal parts is often necessary, especially in the case of large-caliber weapons.

FIG. 4 shows a simplified circuit system for driving a plasma cannon according to the invention.

In this case, reference numeral 10 is a schematic diagram of a plasma cannon, and reference numeral 11 is a simplified circuit chamber. Here, only the projectile 100 is shown in place of the cartridge inside the plasma cannon.

Reference numeral 101 indicates a first electrode, which is connected to the nonave. The second electrode is indicated at 102.

In the circuit chamber 11, what is designated by the reference numeral 110 is a drive device such as a motor supplied with liquid fuel, for example.
What is indicated by the reference numeral 111 is a DC generator. The voltage generated by the DC generator is supplied via switch 112 to capacitor 113, which acts as a capacitive energy storage device. The capacitor 113 is connected to the first electrode 101 via a switch 114, and further connected to the second electrode 101 via an inductance 116.
2 is connected.

Furthermore, the capacitor 113 can be short-circuited via a switch.

To start the acceleration process, a capacitive energy storage device 1
13 is voltage V. is charged to. After switching on the switch 114 at time t=0 (see also FIG. 5), the energy storage device discharges in the accelerator via the inductance 116 and the plasma. Time t=1. When the current reaches the maximum value i max at , the shorting switch 115 is closed. after that,
The decreasing current flow through the accelerated plasma is caused by coil 1
16 inductance.

In order to make the dimensions of the cartridge 8 (FIG. 1) as small as possible, the projectile 80 can also be connected directly to the coaxial inner electrode 83 (distance between inner electrode and projectile=0).

However, it is also possible, preferably in the form of a gap, to fill the gap 88 with a vaporizable material (for example polyethylene). This is because further vaporization of this material increases the plasma pressure so that the projectile leaves 74 Eve 90 at a greater velocity.

[Brief explanation of drawings]

1 is a cross-sectional view of a first embodiment of a cartridge according to the invention; FIG. 2 is a cross-sectional view of a plasma cannon according to the invention having the cartridge shown in FIG. 2; FIG. 4 is a circuit diagram showing a simplified circuit chamber for driving the plasma cannon according to the invention; FIG. 5 is a diagram showing the flow of current in the plasma cannon; Diagram showing the time course. FIG. 6 is a schematic representation of a known device for accelerating a projectile using an electrically heated plasma. 8... Ammunition cylinder, 9... Closed side part of pipe, 8o.
... Projectile, 81... Jacket, 82... First electrode, 83... Second electrode, 84... Insulating piece, 88
...discharge chamber, 90...pipe. I-1 bu 1 τ White 1st country

Claims (1)

[Claims] 1. Two electrodes are provided for generating plasma, the first electrode being disposed coaxially within the closed part of the pipe, one of which is closed; In a device for accelerating a projectile in said pipe by means of an electrically heated plasma, which is formed as annular electrodes, all parts (81, 82, 82, 83) is easily replaceable, an electrically heated plasma projectile acceleration device. 2. Parts exposed to severe wear (81, 82, 83)
is the closed side part (of the pipe (90)) together with the projectile (80).
9) Device according to claim 1, characterized in that it is assembled in an exchangeable cartridge (8) provided in the cartridge (9). 3. The cartridge is formed from two units, the first unit containing a projectile (80) and a jacket (81) surrounding this projectile, and the second unit containing a contact plate (85, electrodes (82, 83) with (86, 87);
and an insulating piece (84) arranged between the electrodes (82, 83). 4. Device according to claim 2, characterized in that both electrodes (82, 83) together with the projectile (80) form a gap-like discharge chamber (88). 5. The device according to claim 4, characterized in that a vaporizable substance is provided in the gap-shaped discharge chamber (88). 6. The device according to claim 5, characterized in that polyethylene is used as the material that easily vaporizes. 7. According to any one of claims 1 to 6, characterized in that the projectile (80) is surrounded by a combustible jacket (81) made of a substance that easily vaporizes. The device described.