Design of the Ammunition Degreasing Based on PLC in the Ammunition Preparation Operation System

Before the ammunitions are used, repaired, and discarded, the oil layers on the surface must be eliminated, and the ammunition oiling can obviously enhance the antirust and sealing property, and reduce the influences of the temperature and the humidity change, but the ammunition oiling must be eliminated before the ammunitions are used. At present, the degreasing methods mainly include the physical heating, mechanical abrasion, chemical cleaning, and high pressure water washing, and to adopt PLC to control the degreasing of the ammunition preparation operation system could enhance the working efficiency and the safety coefficient of the ammunition test, reduce test personal’s labor intensity, and realize the automatization or semi-automatization of the ammunition preparation operation.

The ammunition degreasing is the key of the preparation operation, and the former traditional degreasing method is to use the flaxes repeatedly scrub and wipe out the ammunition by dipping in kerosene or turpentine.This method wastes human resources and materials, with low working efficiency.Through repeating demonstrations and sufficient survey, the greasing method of using PLC to control the high pressure water is selected in this article.

Components
The equipment is mainly composed by the rotating clamping system, the pneumatic sealing system, the high pressure water washing system, the flushing-prevent system, the compressed air system, and the case (seen in Figure 1).

Rotating clamping system
This system is composed by the principal axis drum, the internal spline rotating axis, the external spline clamp, fixed cylinder, and the motor.
Two rotary sleeves have cone chucks, and their poles have external spline clamps, fixed cylinder, and motor.

Pneumatic sealing system
This system is designed to close the greasing box, and it is composed by two cylinders, two flexible sealing doors, and rotating pins.

High pressure water washing system
This system is mainly used to eliminate the oils on the pill surface, and it is composed by the water box, the high pressure pump, the pressure valve, the selector valve, and the high pressure water nozzle.The working pressure can be adjusted by the pressure valve, and the close and open can be controlled by the selector valve.When the pressure achieves about 10Mpa, the high pressure waters rush to the oiling surface of pills, and eliminate the oiling in short time, and the sewages could be repeatedly used through filtration, if the quantity is large, and if the quantity less, the sewages could be discharge into the ground.

Oil-water flushing-prevent system
When the nozzle of the high pressure water begins spraying water and degreasing oils, if the water on the ammunition and the oils flushed by the water have not been controlled or limited, these waters and oils will splashed to other places of the ammunition, causing secondary pollution, so these oil waters must be drained.The gas-current-limiting is used to control the waste water.On two ends of the ammunition body, there or two or four gas jets, and when the high pressure water begins degreasing, the flushing-prevent system begins to work, and these gas jets begin to spray high pressure air current to the outside, forming two gas screens on two ends of the ammunition body, and these two gas screens can effectively prevent the water current and the eliminated oils flow to the place without oils, so the flushing of sewages can be prevented sufficiently.

Compressed air system
When the degreasing station begins to work, a pressure-consistent gas source needs to be equipped to supply the compressed airs.Furthermore, the clamping equipment of the washing machine, the oil water flushing-prevent system, and the sealing door system all need the compressed air as the power.

Working principle
Except for the water system, other devices of the degreasing system are all placed in the sealing box with transparent observation window to prevent the pollution to the work environment when the high pressure water works.
The procedures of the degreasing work can be described as follows.
(1) By the push of the hydro-cylinder, the ammunition delivering dolly1 delivers the ammunitions to the degreasing station, and sealing door opens, and the system puts the ammunitions into the degreasing box from the vertical direction.
(2) The rotating clamping system begins to work, and clamps the pills, and the V-shape base of the dolly descends, and the sealing door closes.
(3) The electromagnetic clutch of the motor in the clamping system works and drives the rotating axis to rotate.
(4) The flushing-prevent jet system begins to work, and form two gas screens on two ends of the ammunition body.
(5) The high pressure pump works and begins to wash the pills.
(6) After certain time, the high pressure water stops to spray, and the compressed air begins to blow until the pills are dried incompletely.
(8) The ammunition delivering dolly 2 rises from the box, and the sealing board opens, and the system delivers the washed pills to the next station, so the first pill is cleared completely.And when the first pill is delivered to the next station, the dolly 1 delivers the second pill for degreasing.
Above procedures are repeated and the degreasing work can be completed.

Working principle of control system
When the first pill is put on the dolly 1, the control system controls the hydraulic system and delivers the dolly 1 to the degreasing station, and the V-shape base rises, and the pneumatic sealing door opens, and the clamping system begins to work, and the V-shape base descends, and the sealing door closes, and the motor starts and drives the roller to rotate.At the same time, the magnetic valve starts, and the high pressure jet begins to spray high pressure water to the pills, and wash the oils on the surface of pills.After certain time, the motor stops, and the high pressure water magnetic valve acts, and the high pressure water stops spraying, and the gas jets are started to blow the pills.

System chart of the electrical apparatus control system of ammunition degreasing station
The system chart of the electrical apparatus control system of ammunition degreasing station is seen in Figure 2.

I/O point distribution of PLC function system
According to the design of input and output, 13 input points and 25 output points are needed, and the PLC of FX 2 -64MR is selected, and its output form is the relay output, which can drive the AC or DC load, with 32 input points and 32 output points, so it can satisfy the design requirements, and the concrete I/O address distribution is seen in Table 1.

Design of the ammunition degreasing station control circuit
(1) Detect the level of water box.
(2) Detect the air pressure signal of pneumatic pump.
(3) Detect the water pressure signal of high pressure pump.
reduce test personal's labor intensity, and realize the automatization or semi-automatization of the ammunition preparation operation.

Table 1
n Center of Scien