• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.700-707
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• 2016

Recently, ammunition malfunctions of the 40mm grenade were reported during live fire training. When 72 40mm grenades were fired by the army, 11 duds were encountered. The dud ammunition rate was approximately 15%. Because ammunition is used a long time after its manufacture, it is necessary to ensure its performance after long-term storage. In this study, we attempted to decrease the dud ammunition rate of 40mm grenade (K200) fuzes through quality improvement. First, it was determined by the detonator performance test that abnormal explosions occurred due to the degradation of the detonator as a result of its aging characteristics. Second, we improved the fuze quality of the 40mm grenade. Third, we tested its shelf life to estimate its life expectancy. The shelf life of the 40mm grenade fuze obtained using the Arrhenius equation was 6.5 years for the existing grenade fuze and 45.5 years for the improved grenade fuze. This showed that the shelf life of the improved grenade was increased approximately 7 times. Therefore, the improved 40mm grenade fuze contributes to the quality improvement of the 40mm grenade by decreasing the dud ammunition rate during long term storage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4828-4834
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• 2015

From the moment that a firing pin triggers the detonator to the moment that a grenade leaves a barrel is called Action Time. Since a loading and percussion of 40mm grenade happens simultaneously, action time should be within a certain time in order to prevent a Jamming malfunction. Previously, unreliable action time device of 40mm grenade made it difficult to improve quality assurance of K4 Grenade Machine Gun. Here, various sensors were compared and a special device was designed to seek an accurate measurement on action time. In this device, the gap between a signal from an optical sensor in Firing Pin and that from Eddy current probe in the barrel was recorded and data were sent to a computer in real time. Confirming if action time is within the criteria, it is expected that action time plays an important role in quality assurance on 40mm grenade.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.14-22
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• 2016

Because fuses have many parts, human error can occur during visual inspections. This paper proposes an automatic ammunition test algorithm for preventing human error during an inspection. The automatic ammunition test algorithm consists of the following three steps. First, the image input and preprocessing step is where an inspection image is rotated using an image rotation algorithm and the image is converted to a binary image. Second, the inspection step of arming determines if the ammunition is armed using Masked Template Matching algorithm, etc. Third, the inspection step of the parts determines if the parts are omitted using an image searching algorithm, etc. The arming or parts omission of the fuse are detected efficiently using the ammunition automatic test algorithm. The ammunition automatic test algorithm is expected to help improve the safety and reliability of 40 mm grenade fuse.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.130-135
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• 2019

This study performed the quality improvement of a red dot sight for a 40 mm grenade launcher through parallax reduction. The red dot sight cited in this study is currently in mass production for military use as a non-weapon system. While the red dot sight's parallax currently meets requirements, slightly greater error was observed on the outside of effective optical area of the reflection lens compared to other sights. Parallax is easily affected by eye movement, which can result in aiming error. To improve the red dot sight's quality, this study analyzed why parallax is observed in the effective optical area of the reflection lens and how to reduce it. As a result, the red dot sight demonstrated lower parallax error using the new optical system design with an increased reflection lens thickness and modified components configuration related to the reflection lens assembly. Parallax was calculated and simulated by using a particular program to verify that it decreased. This improvement for the 40 mm. grenade launcher red dot sight more than satisfies requirements, offers advanced capabilities for users, and as a result, successful operation carryout.

• Journal of the Korean Magnetics Society
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• v.25 no.3
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• pp.83-86
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• 2015

Nowadays the weapon systems are employed air bursting munition (ABM) as smart programmable 40 mm shells which have been developed in order to hit the target with programmed munition that can be air burst after a set distance in the battlefield. In order to improve the accuracy of such a bursting time, by measuring the speed of the munition from the barrel, weapon systems calculate the exact time of flight to the target and then the time information must be inputted to the munition. In this study, we introduce a device capable of detecting a shot at K4 40 mm automatic grenade. The shot is composed of a rotating copper band to convert linear motion into rotary motion when it passes through the barrel, the steel section is exert the effect of fragment and aluminum section to give fuze information. The aluminum section was used to detect munition using eddy current method. To measure muzzle velocity by means of non-contact method, two eddy current probes separated 10 cm was employed. Time interval between two eddy current probe detection times was used as muzzle velocity. The eddy current probe was fabricated U-shape Mn-Zn ferrite core with enamelled copper wire, and 200 kHz alternating current was used to detect inductance change. Measured muzzle velocity using the developed sensor was compared to the Doppler radar system. The difference was smaller than 1%.