9A234 fuze

[PzGr40]

Who can help me on a drawing of the 9A234 fuze as used in the 9M111 Fagot missile. It is the bakelite fuze in an aluminium housing just below the shaped charge.
Thanks in advance,
regards, DJH

[Nabob]

Will this help?

Regards, Bob

[PzGr40]

Thanks Bob, it helps a lot, I now fully understand the working of the fuze.
The squib ignites the black powder pellet (1) allowing the pin below it to rise and make the detonator rotate in line. At the same moment the fuze is lit , allowing pin 2 to rise and close the electric circuit with the detonator and impact fuze. The last pin, on the end of the pyrotcehnic delay is the self destruct mechanism. When the pin rises, the ignition circuit is closed, exploding the fuze.
Thanks a lot!!!

[Vince]

To be more precise:

-On firing, due to the inertia the V1 switch connects the MV-4-1 igniter to the missile's battery thru the R2 resistor.
-The igniter ignites the powder train and the pyrotechnical safety pin of the booster rotor
-The safety pin frees the rotor which turns into armed position and locks itself by a pin
-When the burning of the powder train reaches the V2 switch (a pin pushed into the place of the burnt powder by a spring, freeing a twisted spring), it connects the C capacitor to the missile's battery thru the R1 resistor and starts loading it.
-When the C is loaded, a contact between the 3 and 4 leg of the fuze (impact) sets off the capacitor detonating the ED-0,5-9 electric detonator.
-When the burning of the powder train reaches the V3 switch (same as V2), it connects the C directly to the ED-0,5-9

Regards,
Vince

[PzGr40]

Thanks , so if I understand well,
-The flame of the igniter pellet (ip), goes left and right (red arrows). It burns away pellet P1 , allowing the detonator shutter to rotate in the armed position.
-At the same moment the pyrotechnic delay starts burning, freening pin P2 and loading the capacitator. (This will probably also form the arming delay upon firing).
-The pyrotechnic delay burns up )blue arrows' until pin P3 is lifted, detonating the fuze, This is the self destruct mechanism.

-Below the P4 wire, a spring loaded set back pin is placed that connects for a short moment upon firing from the tube. It is not clear to me what is is meant for.
-Why is a capacitator used and no direct connection to the battery? Does the capacitator form the launching safety , enshuring the missile is not armed during launch and the first 20 meters after leaving the launching tube? Or does setback Pin P4 shortcircuit the fuze at launch?



Thanks in advance, regards

[Vince]

- First of all: your fuze is a 9E234M for the 9M111-2, 9M111M, and 9M113 (it differs in arming and SD times)
- Below P4 that's the V1 switch
- Yes, the burning time to V2 plus the loading time of the capacitor give the arming delay. I think the capacitor also provides higher and constant voltage level during the whole flight than the pyro-electrical battery.

[Nabob]

As I understand it is because the battery is not a part of the fuze. So the capacitor is there to ensure propper ignition of the detonator. The arming delay is 70m.
Bob

[Vince]

Yes the two batteries are in the missile's instrument compartment. The fuze has a 4 pin connector. Pins 1,2 are for the battery and 3,4 are for the nose sensing element.

[PzGr40]

Thanks for all the info. I am now able to finnish my 9M111-2 cutaway model. A posting will follow.
Regards, DJH