Patent Application
20120204707
The present invention relates to a method and apparatus for charging a small-scale bullet with compressed high-performance composite explosives, and more particularly, to a method and apparatus for manufacturing many bullets charged with compressible composite explosives, wherein explosives are measured in constant amount, simultaneously shaped by using a plurality of pallets, and charged to bullets by compression.
In small or middle caliber bullets, melt-cast explosives are generally used due to easiness in charging, which includes TNT and Composition B (Comp. B). Also used are particle type explosives like Composition A3 (Comp. A3). The conventional explosives, however, are very sensitive to external impact and have high chance of explosion while transport, although they are widely used due to the cheap price and easiness for mass production.
The method of producing bullets by using the melt-cast explosives comprises melting the explosives in a container utilizing the property of the explosives of melting above 80° C., and pouring certain amount of the explosives into the bullet. It is important to cool the explosives slowly so that cracking or excessive contraction is not generated inside the explosives. The above-described melt-cast explosives have the merit of mass production of bullets since the explosives are heated and liquid state explosives are charged to the bullet. However, recently developed new bullets require safety in handling as well as high performance. So, research has been made to increase the stability of the bullet by minimizing the possibility of explosion while carrying and using the bullet, and therefore, much study has been made on the method of charging bullets with compressible composite explosives having greater performance and lower defects compared to conventional explosives.
The compressible composite explosives is generally produced by coating explosives such as HMX(octogen), RDX(hexogen) with polymer materials, and then applying high molding pressure thereby producing solid state pellets. These compressible composite explosives are state of the art explosives which can have controllable explosive performance and sensitivity by controlling the compositions of the explosives, and are applied to the warhead of recently developed guided warfare systems.
The compressible composite explosives, however, has had technical limitation for applying to small caliber bullet due to the difficulty in charging process and manufacturing procedure. In other words, in order to charge the compressible composite explosives to the bullet, particle explosives (Molding Powder) in the shape of powder should be molded under vacuum at very high molding pressure, considering the characteristics of bullet of small and complex internal structure, especially when the bullet is long compared to radius.
Therefore, compressible composite explosives are hardly applied to the small bullet. The applicant of the present invention has filed a Korean Patent Application No. 10-2009-0004285 relating to a precise charging method of compressible composite explosives to the bullet having fragment notch with long length compared to the radius. The patent application, however, relates to a compressible composite explosives charging method which is appropriate for developing stage but not sufficient for manufacturing the bullets in large quantity, which requires additional process and apparatus for applying to a manufacturing method of bullets.
Korean Patent Application No. 10-2009-0004285
The present invention has been designed to solve the above mentioned problem of prior arts and aims to provide a method and apparatus for manufacturing many bullets simultaneously charged with high performance compressible composite explosives safely and uniformly.
More particularly, the present invention relates to a method and apparatus for manufacturing bullets charged with compressible composite explosives, wherein composite explosives are measured in constant amount, simultaneously shaped by using a plurality of pallets, and charged to bullets by compression.
Also, the present invention aims to provide an automated sequence of manufacturing procedure with organically connected and safe method providing basis for automated processes for manufacturing bullets charged with compressible composite explosives.
To accomplish the object of the present invention, the method of the present invention for manufacturing bullet charged with compressible composite explosives comprises a first process in which particle explosives are measured in constant amount by using constant quantity supplying devices and are charged to pallette molds, a second process in which the particle explosives are transferred to a pellet-forming molds by transporting the pallette mold charged with the particle explosives to the constant pressure molding device, and returned to the particle explosives constant quantity supplying device, and then the particle explosives of the pellet-forming mold is molded under constant pressure to a pellet, a third process in which the pellet-forming mold is transported to the upper side of the bullet body fixing mold which is supplied to the constant pressure charging device thereby exiting the pellet of the pellet-forming mold, and then the pellet-forming mold is returned to the constant pressure molding device, and the pellet which is inserted to the bullet in the fixing mold is pressed under constant pressure for charging, a fourth process in which the bullet completely charged with explosives is transported to the bullet separating device along with the bullet body fixing mold, each bullet is separated from the bullet body fixing mold to be supplied to the excess explosives cutting device, and then new bullet body fixing mold is supplied to the constant pressure charging device, and a fifth process in which excess explosives is removed through cutting from bullet.
According to the method for manufacturing a bullet charged with compressible composite explosives of the present invention, the fourth process is performed after repeating the first process through the third process three times.
And the pallette mold and the pellet-forming mold and the bullet body fixing mold are divided into 64 sections so that 64 bullets are produced per one cycle.
Also, the apparatus for manufacturing a bullet charged with compressible composite explosives, according to the present invention, comprises a particle explosives constant quantity supplying device which measures particle explosives in constant amount and charges a pallette mold divided into a plurality of partitions with the explosives; a constant pressure molding device which inserts particle explosives of the pallette mold to the pellet-forming mold and molds the explosives into a pellet by using a plurality of punch operating at the same pressure; a constant pressure charging device which press-charges the pellet of the pallet-forming mold into a bullet body fixing mold by using a plurality of punch operating at the same pressure; a bullet supplying device which supplies the bullet body fixing mold to the constant pressure charging device; a mold transporting means which repeatedly transports the pallet-forming mold between the constant pressure molding device and constant pressure charging device, and repeatedly transports the bullet body fixing mold between the constant pressure charging device and the bullet supplying device; a bullet separating device installed at the bullet supplying device to separate the bullet from the bullet body fixing mold; and an excess explosives cutting device which transports the bullet separated by the bullet separating device to a conveyer and cuts excess explosives of the bullet.
And, the particle explosives constant quantity supplying device comprises a frame provided with a transport guide, a hopper installed at the upper side of the frame with opening and closing slider equipped at an exit, a constant volume measuring mold which exits through a plurality of holes the particle explosives supplied from the hopper in constant amount and charges the mold hole of the pallette mold located at lower portion thereof, and a pallette mold transporting means which transports the pallette mold to the constant pressure molding device when particle explosives is completely charged.
The pallette mold, pellet-forming mold and bullet body fixing mold are respectively equipped with 64 or more of mold holes having the 8×8 structure.
The constant pressure molding device comprises a lower frame housing the pellet-forming mold, a upper frame which is installed in a way to move up and down along a guide bar installed at 4 corners of the lower frame, and a constant pressure chamber located at the lower part of the upper frame to mold the particle explosives into a pellet by applying constant molding pressure to a plurality of punches inserted to the mold holes of the pellet-forming mold.
Also, the constant pressure molding device further comprises a vacuum box so that the pellet forming is carried out under vacuum.
The constant pressure chamber comprises a chamber body which includes a plurality of holes for installing a spool which drives the punch and a groove for interconnecting each hole, and a punch holder which is formed in one body with the chamber body and to which the punch is combined.
The constant pressure chamber further comprises a punch guide installed constant on the lower part of the punch holder to guide the punch.
The constant pressure charging device comprises a lower frame housing the bullet body fixing mold, a upper frame which is installed in a way to move up and down along a guide bar installed at 4 corners of the lower frame, and a constant pressure chamber located at the lower part of the upper frame to charge the pellet to the bullet of the bullet body fixing mold by applying constant molding pressure to a plurality of punches inserted to the mold hole of the pellet-forming mold.
The constant pressure charging device further comprises a vacuum box so that the pellet molding is carried out under vacuum.
The bullet body fixing mold comprises a lower mold which is equipped with a plurality of holes to which the bullet is inserted, and a upper mold which is equipped with a plurality of holes into which the punch is inserted and which is combined detachably to the lower mold fixing the bullet which is aligned to the lower mold.
Here, only the lower mold among the bullet body fixing mold can be transported to the bullet supplying device.
The bullet supplying device comprises a transport guide for fixing bullet body fixing mold so that the process of fixing a plurality of bullet to the bullet body fixing mold, transporting the bullet body fixing mold to the constant pressure charging device and separating the bullet transported from the constant pressure charging device from bullet body fixing mold is carried out sequentially, the transport guide being constructed so that 3 or more of bullet body fixing molds are arranged and each process is carried out continuously through the orbital shape of the transport guide.
The bullet separating device comprises a finger frame which picks up the bullet of the bullet body fixing mold by using a plurality of fingers that can pick the bullet and transports to the conveyer of the cutting device of excess explosives, a lifting cylinder installed on a main frame to lift the finger frame, and a transport means installed on the main frame to transport the finger frame to the direction of the excess explosives cutting device.
The excess explosives cutting device comprises a cutter for cutting the explosives charged over the bullet, a supply conveyer for transporting the bullet supplied from the bullet separating device to the cutter, a exit conveyer for exiting the bullet from which excess explosives is removed by the cutter, and a bullet holding wheel which picks up each bullet of the supply conveyer in a way the metal section of the bullet is located perpendicularly to the blade of the cutter and supplies the bullet to the cutter, and supplies the bullet with excess explosives removed to the exit conveyer.
The mold transporting means is composed of a first transport means which transports the pellet-forming mold and a second transport means which transports the bullet body fixing mold, the first transport means being operated to transport the pellet-forming mold at a higher position compared to the second transport means.
By using the method and apparatus for manufacturing a bullet charged with high performance compressible composite explosives of the present invention, it is possible to produce bullets in a large scale by charging the bullet with compressible composite explosives safely and uniformly.
According to the method and apparatus of the present invention, a high performance stable bullets charged with compressible composite explosives are manufactured by measuring the composite explosives in constant amount, simultaneously molding by using a plurality of pallets, and charging the molded explosives to a bullet by compression, the processes being carried out sequentially.
The method for manufacturing a bullet charged with compressible composite explosives according to the present invention will be described in more detail with reference to the drawings attached.
The method for manufacturing a bullet charged with compressible composite explosives according to the present invention, as shown in
At this step, it is preferable to perform the fourth process after repeating the first process through the third process three times since it is impossible to fully charge the bullet 45 by using only one pellet 25′. Also, each of the pallette mold 15, pellet-forming mold 25 and bullet body fixing mold 35 is preferably divided into 64 partitions, one cycle producing 64 bullets 45.
The method for manufacturing a bullet charged with compressible composite explosives as described above is carried out as follows.
In the first process, particle explosives is measured in constant amount by using a particle explosives constant quantity supplying device 10, then charged to a pallette mold 15, and then the pallette mold 15 is transferred to a constant pressure molding device 12.
And, in the second process, the particle explosives supplied through the pallette mold 15 from the constant pressure molding device 12 is molded into pellet 25′ under constant pressure, in which 64 pellets 25′ are simultaneously molded in one molding process. During the second process, the pallette mold 15 is transported to the particle explosives constant quantity supplying device 10, carrying out the first process independently. In other words, the particle explosives are measured in constant amount in order to supply the particle explosives to the second process.
In the third process, the pellet 25′ molded at the constant pressure molding device 20 is transported to the constant pressure charging device 30 along with pellet-forming mold 25 for charging to the bullet 45, and then the pellet 25′ of the pellet-forming mold 25 is charged to the bullet 45 of the bullet body fixing mold 35 under constant pressure. In the third process, the pellet 25′ is exited to the bullet body fixing mold 35, and then the exited pellet-forming mold 25 is returned to the constant pressure molding device 20, repeating the process of the second process, and the constant pressure charging device 30 presses and charges the pellet 25′ at the 64 bullets 45 simultaneously. At this step, three pellets 25′ at the bullet 45 are changed repeating the first through the third process three times, thereby completing constant pressure charging of the pellet 25′ at the 64 bullets 45.
In the fourth process, the completely charged bullet 45 at the pellet 25′ is transported along with the bullet body fixing mold 35 to the bullet separating device 50, and after the bullet body fixing mold 35 is transported to the bullet separating device 50, another bullet 45 at the fixed new bullet body fixing mold 35 is transported to the constant pressure charging device 30 waiting for being processed by the third process.
Finally, in the fifth process, the excess explosives of the bullet 45 is removed, thereby after excess explosives is completely cut, 64 bullets 45 with high performance compressible composite explosives charged are obtained.
In summary, starting from particle explosives, the process, in which bullet is charged with explosives and excess explosives is removed, is carried out in one cycle, each process being operated organically while independently, thereby greatly increasing the manufacturing capacity through automation.
Meanwhile, the apparatus of the present invention for manufacturing a bullet charged with compressible composite explosives, as illustrated in
The particle explosives constant quantity supplying device 10 comprises a frame 11 provided with a transport guide, a hopper 12 installed at the upper side of the frame 11 with opening and closing slider equipped at an exit, a constant volume measuring mold 13 which exits through a plurality of holes the particle explosives supplied from the hopper 12 in constant amount and charges the mold hole of the pallette mold located at lower portion thereof, a pallette mold transporting means 14 which transports the pallette mold to the constant pressure molding device 20 when particle explosives is completely charged, a main hopper 16 storing the particle explosives, and a conveyor 17 which supplies the particle explosives of the main hopper 16 to the hopper 12.
Here, the constant volume measuring mold 13 charges the pallette mold 15 with particle explosives per row, and the pallette mold transporting means 14 transports the pallette mold 15 with constant pitch until particle explosives is charged in all the mold hole of the pallette mold 15. In other words, the constant volume measuring mold 13 has 8 holes formed therein and the pallette mold 15 has 64 mold holes with 8×8 structure, thereby the constant volume measuring mold 13 charges at a rate of 8 rows per each cycle and the pallette mold transporting means 14 transports the pallette mold 15 in the unit of 1 row of the mold hole.
And, the constant pressure molding device 20 comprises a lower frame 21 housing the pellet-forming mold 25, a upper frame 23 which is installed in a way to move up and down along a guide bar 22 installed at 4 corners of the lower frame 21, a constant pressure chamber 24 located at the lower part of the upper frame 23 to mold the particle explosives into a pellet 25′ by applying constant molding pressure to a plurality of punches 25′ inserted to the mold hole of the pellet-forming mold 25, and a vacuum box 27 which separates the inner side where the pellet-forming mold 25 locates from the outer side so that pellet molding is carried out under vacuum.
Here, a hydraulic device 28 for operating the constant pressure chamber 24 and a vacuum exiting means (not shown) for introducing vacuum to the vacuum box 27 are installed on the upper frame 23.
Meanwhile, the constant pressure chamber 24 comprises a chamber body 24a which includes a plurality of holes for installing a spool 24b which drives the punch 26 and a groove 24c for interconnecting each hole, a punch holder 24d which is formed in one body with the chamber body 24a and to which the punch 26 is combined, and a punch guide 24e installed on the lower part of the punch holder 24d to guide the punch 26. The punch 26 is preferably installed in a way not constant to the punch holder 24d so that the punch can move up and down. Also, the pellet-forming mold 25 is processed at the inlet of the mold hole with chamfering 25″.
Also, the pellet-forming mold 25 and bullet body fixing mold 35 have 64 mold holes with 8×8 structure, as well as the constant pressure chamber 24 which has 64 punches 26 with 8×8 structure, thereby making it possible to mold 64 pellets 25′ simultaneously.
The constant pressure charging device 30 comprises a lower frame 31 housing the bullet body fixing mold 35, a upper frame 33 which is installed in a way to move up and down along a guide bar 32 installed at 4 corners of the lower frame 31, a constant pressure chamber 34 located at the lower part of the upper frame 33 to charge the pellet 25′ to the bullet 45 of the bullet body fixing mold 35 by applying constant molding pressure to a plurality of punches 36 inserted to the mold hole of the pallette mold 25, and a vacuum box 37 which separates inner side where the pallette mold 25 resides from outré side so that the pellet molding is carried out under vacuum.
Here, the constant pressure charging device 30 is also installed at the upper frame 31, and is equipped with a hydraulic device 38 for driving the constant pressure chamber 34 and a vacuum exiting system (not shown) for introducing vacuum to the vacuum box 37. The construction of the constant pressure chamber 34 is the same as that of the constant pressure chamber 24 of the constant pressure molding device 20 except for some functional aspects and so the explanation is omitted.
Meanwhile, the bullet body fixing mold 35 comprises a lower mold 35a which is equipped with a plurality of holes to which the bullet 45 is constant, and a upper mold 35b which is equipped with a plurality of holes into which the punch 36 is inserted and which is combined detachably to the lower mold 35a fixing the bullet 45 which is constant to the lower mold 35a. The hole of the lower mold 35a is preferably processed larger than the external radius of the bullet, and the hole of the upper mold 35b is preferably processed larger than the external radius of the punch 36. And only the lower mold 35a among the bullet body fixing mold 35 is transported to the bullet supplying device 40 and the upper mold 35 remains with no transport.
Herein, more than necessary amount of pellet 25′ is charged to the bullet 45 at the constant pressure charging device 30, which is in consideration of the processing error in manufacturing the bullet and the error in molding the pellet 25′. In other words, the bullet 45 is charged with excessive amount of pellet 25′, and then the unnecessary excess explosives is cut out, thereby making the amount of the pellet 25′ charged to the bullet 45 in optimum amount.
And, the bullet supplying device 40 comprises a transport guide 41 for fixing bullet body fixing mold 35 so that the process of fixing a plurality of bullet 45 to the bullet body fixing mold 35, transporting the bullet body fixing mold 35 to the constant pressure charging device 30 and separating the bullet transported from the constant pressure charging device 30 from the bullet body fixing mold 35 is carried out sequentially, the transport guide 41 being constructed so that 3 or more of bullet body fixing molds 35 are arranged and each process is carried out continuously through the orbital shape of the transport guide 41.
Also, the bullet separating device 50 comprises a finger frame 53 which picks up the bullet 45 of the bullet body fixing mold 35 by using a plurality of fingers 52 that can pick the bullet 45 and transports to the conveyer of the cutting device 60 of excess explosives, a lifting cylinder 54 installed on a main frame 51 to lift the finger frame 53, and a transport means 55 installed on the main frame 51 to transport the finger frame 53 to the direction of the excess explosives cutting device 60.
And the excess explosives cutting device 60 comprises a cutter 65 for cutting the explosives charged over the bullet 45, a supply conveyer 61 for transporting the bullet 45 supplied from the bullet separating device 50 to the cutter 65, a exit conveyer 62 for exiting the bullet 45 from which excess explosives is removed by the cutter 65, and a bullet holding wheel 63 which picks up each bullet 45 of the supply conveyer 61 in a way the metal section of the bullet 45 is located perpendicularly to the blade of the cutter 65 and supplies the bullet 45 to the cutter 65, and supplies the bullet 45 with excess explosives removed to the exit conveyer 62.
Meanwhile the mold transporting means 70 is composed of a first transport means 71 which transports the pellet-forming mold 25 and a second transport means 72 which transports the bullet body fixing mold 35, the first transport means 71 being operated to transport the pellet-forming mold 25 at a higher position compared to the second transport means 72, the first transport means 71 being operated to move the pellet-forming mold 25 at higher location compared to the second transport means 72.
By using the apparatus for manufacturing a bullet charged with compressible composite explosives as described above, particle explosives is molded into a pellet and the process of charging into the bullet is carried out sequentially.
The particle explosives constant quantity supplying device 10 has the role of supplying particle explosives in constant amount to mold pellet 25′ of uniform standard, and can supply particle explosives to the pallette mold 15 in constant amount by calculating the volume. In other words, in order to mold the pellet 25′, necessary amount of the particle explosives is calculated in volume, and then particle explosives in the amount corresponding to the volume is filled into the pallette mold 15.
The particle explosives which is supplied from the main hopper 16 where the particle explosives is contained in the hopper 12 before being supplied to the constant volume measuring mold 13, and the 8 holes installed on the constant volume measuring mold 13 is filled with particle explosives as the open-closed slider on the lower portion of the hopper 12 is opened. At this stage, when the constant volume measuring mold 13 is fully filled with particle explosives, the open-closed slider is closed so that the constant volume measuring mold 13 is filled with precise amount of volume of particle explosives.
Thereafter, the pallette mold 15 moves by one pitch by the pallette mold transporting means 14, the particle explosives in the constant volume measuring mold 13 is supplied to the pallette mold 15 as soon as the hole of the constant volume measuring mold 13 and the mold hole of the pallette mold 15 coincides. At this stage, due to the 64 mold holes installed on the pallet mold 15, the constant volume measuring mold 13 which includes 8 holes supplies particle explosives to the pallette mold 8 times sequentially.
Thereafter, the pallette mold 15 is moved to the constant pressure molding device 20 by the pallette mold transporting means 14 and supplies particle explosives to the pellet-forming mold 25 installed on the constant pressure molding device 20, and the pallette mold 15 with empty mold hole is returned to the particle explosives constant quantity supplying device 10 and repeatedly carries out the above processes, thereby repeatedly supplying particle explosives to the pellet-forming mold 25 of the constant pressure molding device 20.
Here, the weight of the particle explosives is measured by the particle explosives constant quantity supplying device 10, which showed margin of ±0.1 g at constant quantity of 3.5 g. The margin of ±0.1 g is considered to be generated from the difference of the size of particle explosives.
When particle explosives is supplied to the pellet-forming mold 25, the constant pressure molding device 20 starts to operate the process the molding of the pellet. The constant pressure molding device 20 is designed considering mass productivity and stability, in which the concept of molding under constant pressure is introduced to secure first spatial stability and then secure moldability of the gunpowder. Hence, the concept of molding under constant pressure make it possible to secure stability and moldability when a plurality of punches 26 are used to simultaneously mold a plurality of pellets 25′. In the process, the constant pressure chamber 24 is placed between the hydraulic device 28 and the punch 26 so that the pressure generated from the hydraulic device 28 is uniformly distributed and transferred to each punch 26 by the constant pressure chamber 24.
Since the constant pressure chamber 24 is filled with grease and oil, as the pressure generated by the contact of the punch 26 installed at the particle explosives and the constant pressure chamber 24 is transferred to the constant pressure chamber 24, the grease and oil moves along the groove 24c connected to each punch 26 and spool 24b, thereby maintaining the pressure in the constant pressure chamber 24 uniformly and finally making the same pressure applied to each punch 26.
This concept of molding under constant pressure is based on the theory of Pascal which means that all forces applied at any one random point inside the fluid is the same, which allows in the present invention that uniform mold density is obtained due to the same pressure applied to the 64 punches. Also, excessive local power applied to some punches 26 is basically prevented, thereby securing the safety of the process. By utilizing the concept of molding under constant pressure, there is also the merit of obtaining relatively uniform mold density since same pressure is transferred despite the variance of the height of the molded body due to the difference in the weight of the particle explosives during molding.
The constant pressure molding device 24 includes 64 punches 26, each punch 26 being installed not fixed in order to be able to move with constant interval, so they are arranged naturally as the punch 26 is inserted inside the pellet-forming mold 25 during the pellet molding and enables molding the particle explosives into pellet 25′. On the pellet-forming mold 25 is installed 64 mold holes, and the particle explosives supplied to each mold hole is molded into pellet 25′ by the punch 26.
The order of process in the constant pressure molding device 20 is as follows.
When particle explosives is supplied from the particle explosives constant quantity supplying device 10 to the pellet-forming mold 25, the vacuum box 27 of the constant pressure molding device 20 moves downward, thereby setting the region near the pellet-forming mold 25 at vacuum. As the vacuum box 27 moves down 64 punches 26 also moves down and stops right above the pellet-forming mold 25. Thereafter, when inside of the vacuum box 27 reaches a near vacuum of 20 mmHg (the complete vacuum corresponds to 0 mmHg in this specification) the punch 26 is inserted into the mold hole of the pellet-forming mold 25, thereby contacting the particle explosives with the punch 26.
At this state, when the punch 26 moves down by the hydraulic device 28, pressure is generated between the particle explosives and the punch 26, and then the pressure generated is transferred to the spool 24b in the constant pressure chamber 24, thereby compressing the operational oil body including a mixture of grease and oil and maintaining constant pressure in the constant pressure chamber 24. If the pressure inside the constant pressure chamber 24 is maintained at a constant pressure, the molding pressure of the punch 26 is also maintained at the constant pressure, and the particle explosives is molded into a 25′ while maintaining the constant pressure state for 30 seconds or more.
The pressure applied by the punch 26 to mold the pellet 25′ is 1757 kg/cm2(25000 psi), and is maintained for 30 seconds or more, then the punch 26 is separated from the pellet-forming mold 25, thereby exiting from the vacuum state with the vacuum box 27 being lifted. With this one cycle of molding process, 64 pellets 25′ are molded.
The table 1 shows the density distribution of 64 molded pellets. As shown in the table, when theoretical maximum density of the particle explosives is 1.763 g/cc, the density distribution of the pellets molded under constant pressure is in the range of 1.750 g/cc-1.761 g/cc, which corresponds to 99.26%-99.88% of the theoretical maximum density. The pellet density shows high density with uniform distribution.
Meanwhile, at the constant pressure chamber 24 is equipped a punch guide 24e so that the punch 26 is uniformly inserted into the inside of the pellet-forming mold 25. Here, the inlet of the pellet-forming mold 25 is processed with chamfering 25″ so that metallic friction is minimized when the punch 26 is inserted.
Meanwhile, the pellet 25′ which is completely molded in the pellet-forming mold 25 remains inside the pellet-forming mold 25 without being separated. This is for the pellet 25′ to be press-charged to the bullet 45 more efficiently. In other words, since the pellet 25′ is inserted into the bullet 45 by moving the pellet-forming mold 25 above the bullet body fixing mold 35 in which the bullet 45 is installed while the pellet 25′ is present, there is no need for another device for separating the pellet 25′ from the pellet-forming mold 25 and then inserting again into the bullet 450. Also, the method of supplying pellet 25′ to the bullet 45 by using the pellet-forming mold 25 is very efficient in automation and provides the effect of productivity in manufacturing.
The pellet 25′ which is completely molded is charged to the bullet 45 by using the method disclosed in the Korean patent application no. 10-2009-004285, which includes the step of press-charging 3 pellets 25′ to the inside of the bullet 45 sequentially. In using this method, the concept of molding under constant pressure which is introduced to sequentially charge 64 bullets 45 with pellet 25′ is applied in charging the bullet 45. In other words, 64 pellets 25′ molded at the constant pressure molding device 20 are simultaneously supplied to the bullet 45 and the concept of press-charging under constant pressure is applied by using the 64 punches 36 installed on the constant pressure charging device 30. By repeating the process three times, the bullet is charged with pellet more quickly, thereby securing security and productivity of charging the bullet.
The constant pressure charging device 30 for this process has similar construction to the construction of the constant pressure molding device 20 except that the punch 36 used and the bullet body fixing mold 35 fixing the bullet have different structures. When pellet 25′ is completely molded, the pellet-forming mold 25 is transported to the constant pressure charging device 30. At this stage, the constant pressure charging device 30, the bullet 45 is in wait state fixed to the bullet body fixing mold 35 which fixes the bullet 45. As transported pellet-forming mold 25 moves to the upper portion of the bullet body fixing mold 35, the punch 36 of the constant pressure charging device 30 slowly moves down pushing in the pellet 25′ at the pellet-forming mold 25 into the bullet 45. When the pellet 25′ is inserted into the bullet 45, the pellet-forming mold 25 is returned to the constant pressure molding device 20, and the upper mold 35b of the bullet body fixing mold 35 is assembled to the lower mold 35a.
When the bullet 45 is completely fixed to the upper and lower mold 35a, 35b of the bullet body fixing mold 35, the vacuum box 37 moves down to the bullet body fixing mold 35 and vacuum state under 20 mmHg is generated. When vacuum state is reached, the punch 36 of the constant pressure charging device 30 moves down and contacts the pellet 25′, thereby generating pressure to each punch 36 which is transferred to the constant pressure chamber 34.
The pressure is transferred to the operational fluid composed of grease and oil inside the constant pressure chamber 34, and the inside of the constant pressure chamber 34 is set to the same pressure and the same pressure is applied to the punch 36, and then the punch 36 press-charges the pellet 25′ inside the bullet 45 under constant pressure. The pressure by which the pellet 25′ is press-charged to the bullet 45 is the same as the pressure of molding the pellet 25′, which is 1757 kg/cm2(25000 psi). In this way, 64 pellets 25′ are simultaneously charged to the 64 bullets 45 per one cycle, and by repeating this process three times, the process of press-charging pellet 25′ to 64 bullets 45 is completed.
When the bullet 25 is completely charged with pellet 25′, among the bullet body fixing mold 35, the upper mold 35b is separated from the lower mold 35a, and the lower mold 35a is transported to the bullet supplying device 40 by the second transport means 72 with the bullet 45 fixed.
The bullet body fixing mold 35 which is supplied to the bullet supplying device 40 is transported to the bullet separating device 50 along the transport guide 41 in the shape of orbit, and new bullet body fixing mold 35 is supplied to the constant pressure charging device 30 by the second transport means 72 and stays in wait state for charging. Then, the bullet 45 inside of which is empty is manually fixed to other bullet body fixing mold 35.
The bullet separating device 50 efficiently separates the bullet 45 from the bullet body fixing mold 35 by using the finger 52 that can pick up the bullet 45. In other words, the finger frame 53 moves down by the lifting cylinder 53 and the finger 52 can pick up the bullet 45 of the bullet body fixing mold 35, and then the finger frame 53 moves up and supplies the bullet 45 to the excess explosives cutting device 60 by moving horizontally or rotating by the transport means 55.
The excess explosives cutting device 60 has the role of cutting the portion of explosives which is charged over the bullet 45 when the pellet 25′ is charged to the bullet 45. The reason that the pellet 25′ is charged over the bullet 45 is that the height of the bullet 45 varies due to the process error of the bullet body and that the size of the molded pellet 25′ also varies slightly. For this reason, the pellet 25′ is molded slightly bigger than actually necessary in charging and charged to the bullet 45, and so explosives is generally charged over the bullet 45.
The excess explosives cutting device 60 cuts the excess explosives by using the cutter 65 as the bullet 45 separated by the bullet separating device 50 moves sequentially one by one along the supply conveyer 61. More specifically, when the bullet 45 transported by the supply conveyer 61 is picked up by the bullet holding wheel 63 and placed in perpendicular with the cutter 65, the cutter 65 cuts excess explosives of the bullet 45. At this time, the cutter 65 contacts metal section of the bullet 45 in order to set reference plane and moves perpendicularly with reference to the cross section of the bullet 45 and cuts the excess explosives over the bullet. In this way, excess explosives of the bullet 45 is removed by the excess explosives cutting device 60, which completes the process of charging compressible composite explosives to the bullet 45.
Preferable embodiments of the present invention have been described in the specification. The examples, however, are not intended to limit the present invention to specific embodiments and any one who is skilled in the art may be able to modify the invention appropriately within the scope of the invention as described in claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2010-0066164 | Jul 2010 | KR | national |
