JPH0740880Y2 - Training bullets - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a training bullet equipped with a drag cone that imparts aerodynamic resistance to shorten the landing distance.

[Background of technology]

The training bullet described above has a trajectory that is almost the same as a real bullet within a predetermined time after launch, and then decelerates rapidly to land at a short-distance point such as the launch site. By doing so, the landing point as an actual bullet is calculated.

An example of the above-described live bullet and its related device will be described with reference to FIG.

The bullet 1 is a bullet 2 and a stabilizing wing 3 fixed to the tail of this bullet
Mainly constituted by and, the chain cap 4 holds the ammunition body 2 at its axial center position. The chain cap 4 is formed as a thick-walled cylinder as a whole by a plurality of pieces divided in the axial direction, and the occipital region 4a formed at the rear portion is tightly bound with a band 5 to integrate the plurality of pieces. There is. In addition, the frontal head 4b of the chain cap 4 is flared to the front, and the outer peripheral surfaces of the frontal head and the band 5 are fitted to the inner surface of the gun cavity. The chain cap 4 is fitted into the cartridge case 6 and loaded into the gun together with the cartridge case.

Therefore, when the propellant 8 is detonated by the detonator 7, the chain cap 4 is rapidly propelled in the gun cavity along with the live ammunition 1, and when the shell 5 leaves the muzzle, the chain cap 4 is acted on by the ram pressure acting on the flare frontal head 4b. Is divided into the above-mentioned pieces and scattered, and thereafter only the actual bullet 1 flies.

[Conventional technology]

7 and 8 exemplify a training bullet corresponding to the actual bullet 1.

This training bullet 10 is related to the proposal of the linemental company in West Germany (Jane's Armor and Artillery 85), and the bullet 11
A drag cone 12 is provided at the rear of the stabilizer blade 3 in place of the stabilizing wing 3 (FIG. 6), and a plurality of through holes 13 directed in the machine axis direction are bored point-symmetrically in the drag cone. The manner of loading the gun is the same as in the case of FIG.

Therefore, when the training bullet 10 is fired, a large amount of aerodynamic resistance acts on the tail of the training wing 3 as compared with the stabilizing wing 3, and as a result, the training bullet 10 lands at a short distance point with a greater deceleration than the actual bullet. The aerodynamic resistance is proportional to the projected area of the drag cone and almost proportional to the square of the flight speed, and the training bullet is indexed backward by the air space generated immediately after the drag cone 12. The through hole 13 serves to reduce the indexing action by connecting the air space with the high pressure region generated immediately before the drag cone 12. Since the air pressure in this high-pressure region is almost proportional to the square of the flight speed, the above-mentioned killing effect is remarkable in the high-speed region of the training bullet 10, that is, within a predetermined time after the launch, and the flight speed, and thus the trajectory, is real. Is similar to that of. The firing range of this training bullet is about 7km, compared to 30km of the actual bullet.

[Problems to be solved by the device]

However, such a conventional training bullet has a problem in that its shot distance cannot be shortened sufficiently.

As described above, by loading the training bullet into the gun in the same manner as the real bullet, the maximum outer diameter of the drag cone cannot exceed the diameter of the stabilizing wing in the real bullet, and in this state the drag cone This is because a large number of through holes have to be formed, so that the projected area is reduced.

In addition, when it is difficult to obtain a wide range like Japan, it is required to shorten the range of the shot.

Therefore, an object of the present invention is to provide a greater aerodynamic resistance after the lapse of the predetermined time.

[Means for Solving the Problems]

The means of the present invention, which has solved this problem, is a training bullet with a drago cone whose tail increases in diameter toward the rear to impart aerodynamic resistance, and the cone of the drag cone is elastically deformed inward. The present invention is characterized in that a plurality of possible tongue-shaped resistance plates are used, and a space is provided between the tongue-shaped resistance plates to form a conical shape with slits.

[Action]

 This means works as follows.

When the training bullet is launched from the gun at a high speed, the cone portion of the drag cone receives a large dynamic pressure at this moment, so the multiple tongue-shaped resistance plates elastically deform inward to narrow the slit width, and the cone Reduce the part diameter. This causes the drag cone's drag coefficient to drop sharply immediately after firing, causing the training bullet to leave the muzzle at about the same speed as a live bullet.

And as the flight speed decreases over time,
The resistance plate expands the cone portion diameter while expanding outward with its elasticity to increase the resistance coefficient. Therefore, the deceleration of the training bullet increases, and due to this increase, the aerodynamic resistance acting on the resistance plate decreases with the above-mentioned squared relationship, so that the restoring speed of the resistance plate is synergistically increased accordingly. That is, as a result of the coefficient of resistance due to the cone portion jumping synergistically,
The training bullet is suddenly decelerated and hits an extremely short distance.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 and 2.

The body 21 of this training bullet 20 has its weight adjusted in the same way as the actual bullet, and the drag cone 25
Are fitted and fastened with nuts 24 via washers 23.

The drag cones 25 are made of elastic metal, and a plurality of drag cones 25 are attached to the studs 22 from the base end portion 26, in this example, 8
A resistance plate 27 having a tongue shape is extended and a cone portion 28 is formed by these resistance plates. Then, by forming a required gap 29 between each resistance plate 27, each resistance plate becomes a third gap.
As shown in the figure, it can be deformed concentrically inward.

This FIG. 3 shows a state in which the diameter of the cone portion 28 is sufficiently reduced by the above deformation until the gap 29 becomes very small (29 ').
In this state, the resistance coefficient of the cone portion is equal to that of the stabilizing blade 3
The size of the initial gap 29 is set so as to be substantially equal to that of (FIG. 6), and the elastic characteristic of the resistance plate 27 is set so that this state can be obtained by the dynamic pressure immediately after the firing.

Therefore, when the training bullet 20 is set in the mode shown in FIG. 6 and is fired from the gun at a high speed, the resistance plates 27 that have spread as shown in FIG. It deforms inward to the state shown in the figure. Since the resistance coefficient at this time is set as described above, the training bullet 20 flies in a trajectory similar to that of the actual bullet.

After that, as the flight speed of the training bullet 20 decreases with the passage of time, the dynamic pressure also decreases. Therefore, each resistance plate 27 restores to the state of FIG. 1 while synergistically increasing the restoring speed as described above. . Aerodynamic resistance increases sharply from this, and the training bullet is rapidly decelerated.

As shown in FIG. 3, even when the resistance plate 27 is deformed to this state, if a slight gap is left between these resistance plates, this gap 29 ′ will cause the gap 29 ′ to pass through the hole 13 ( Sixth
(See Fig.), The indexing effect of the airspace can be reduced.

4 and 5 show this training bullet 20, the conventional training bullet described above.
Simulation results are shown for characteristics of 10 and live bullet 1, and graphs I, II and III in the respective figures are for training bullets 20, 10 and live bullet 1, respectively.

The horizontal axis of FIG. 4 is the flight speed, and the vertical axis is the resistance coefficient based on the cross sectional area of the body of the bullet. As shown in the figure, the resistance coefficient changes from right to left in the graph after firing.

As you can see in the figure, Graph II is Graph III from the beginning.
In contrast to this, with a distance from, the graph I shows a similar tendency, but in the graph I, at the beginning of the graph, the graph I showed a sharp rise after approaching the graph III. Therefore 20 training bullets
Reproduces the trajectory of real bullet 1, then decelerate suddenly and land at a close range.

The horizontal axis of FIG. 5 is the shooting distance, and the vertical axis is the flight speed. As described above, the shooting distances of the real bullet 1 and the training bullet 10 are 30 respectively.
This is about 4km for Training Bullet 20 compared to km and about 7km
Is greatly shortened.

[Effect of device]

As described above, the training bullet of the present invention has the drag cone whose diameter can be expanded rearward and whose opening can be changed depending on the magnitude of the dynamic pressure. It can be fired at an equivalent speed and can be significantly decelerated by expanding the drag cone and increasing the drag coefficient as the flight speed decreases. Therefore, a large amount of aerodynamic resistance is added to the training bullet after a predetermined time has elapsed, the speed is rapidly reduced, and the shooting distance can be greatly shortened, enabling firing training in a narrow range.

[Brief description of drawings]

FIG. 1 is a sectional side view of an essential part showing an embodiment of the present invention, and FIG.
1 is an end view of FIG. 1 as seen in the direction of arrow II, FIG. 3 is a cross-sectional view showing the operating mode of the above embodiment, and FIGS. 4 and 5 are graphs showing the operating characteristics of the above embodiment. FIG. 6 is a cross-sectional side view of an essential part showing a device mode of an actual bullet, FIG. 7 is a side view illustrating a conventional training bullet, and FIG. 8 is an end view of FIG. 7 as seen in the direction of arrow VIII. 20 ... Training bullet 25 ... Drag cone 27 ... Resistor plate 28 ... Cone part

Continuation of the front page (56) Bibliographic references Sho 62-148899 (JP, U) US Patent 4295617 (US, A)

Claims (1)

[Scope of utility model registration request] 1. In a training bullet having a tail portion with a drag cone whose diameter increases toward the rear for imparting aerodynamic resistance, the cone portion of the drag cone has a plurality of tongues capable of elastically deforming inward. A training bullet, characterized in that it is formed into a conical shape with slits between each of the tongue-shaped resistance plates using a resistance plate.