scholarly journals Preventive maintenance pada mesin die casting dengan age replacement model untuk peningkatan reliabilitas mesin

Author(s):  
Andriani Andriani ◽  
Ikhsan Romli

In an industry, the maintenance department plays a very important role in ensuring the smooth production process. The method of machine maintenance with preventive maintenance is a strategy that can be used to repair existing machines. This is related to proper and regular maintenance can improve engine performance and reduce the level of engine damage which will increase the continuity of production activities. In the die casting division of PT Astra Honda Motor in the observation on the die casting machine 07 there were 45 times damage to the ladle component and 11 times the damage to the auto spray component. These two components are critical components of the 07 die casting machine. After testing the compatibility index and the good compatibility of the damage time data and repair time data to obtain distribution data distribution patterns, obtain the tablespoon component MTTF assessment results of 107,833 hours and auto spray components amounting to 314,226 hours. Whereas the MTTR value of the spoon component is 0.385 hours and the auto spray component is 0.766 hours. The next step is to look for critical component replacement time intervals with the age replacement model, to further review whether it is related to increased reliability, decrease in total downtime, and cost savings before preventive maintenance is carried out and after preventive maintenance is carried out.

2011 ◽  
Vol 71-78 ◽  
pp. 4199-4202
Author(s):  
Bo Ya Zhao ◽  
Song Yang ◽  
Zhe Zhang ◽  
Ri Sheng Sun

In this paper an optimal maintenance policy for a Reactor Protection System (RPS) for a nuclear plant was developed. RPS consists of continuously operating sub-systems that were subject to random failures. A block system diagram for RPS had been proposed that facilitates analyzing of individual sub-systems separately. The proposed maintenance policy is the Age Replacement model, which incorporated both corrective and preventive maintenances. A Markov model was used to optimize the preventive maintenance interval of those sub-systems whose failure and repair rates were exponentially distributed. Finally, a sensitivity analysis had been performed and recommendations for maintaining the required RPS availability have been suggested.


2020 ◽  
Vol 22 (2) ◽  
pp. 1-12
Author(s):  
Endang Prasetyaningsih ◽  
Ilyas Ruchiyat ◽  
Chaznin R. Muhammad

Engine performance will decrease when it is operated continuously so that maintenance is needed. Improper maintenance time intervals can reduce engine reliability and still causes machine damage suddenly. Therefore, maintenance time intervals must be determined precisely. This study aims to determine the engine maintenance time intervals using Reliability Theory and Age Replacement Model, then calculate the total maintenance cost. The result shows that the application of new maintenance time interval increases machine reliability.


Author(s):  
Ali Aflah Muzakki

The smooth production process of PT Nugraha Indah Citarasa Indonesia is often disrupted because AM Korin machines that act for filling processes often experience damage and cause the need to repair components that are very detrimental to the company because of the time lost for production due to breakdown of these engine components, causing production loss. Preventive maintenance schedule is needed to prevent damage in the future to find out the maintenance time intervals for AM Korin engine components so as to eliminate downtime based on selection with the most minimal cost savings. Age Replacement is a preventive replacement based on the age of the component by following a certain distribution pattern. So preventive replacement is carried out by re-establishing the time interval for the next preventive replacement in accordance with a predetermined interval in the event of a replacement due to the damage that occurred. The Age Replacement method serves to accurately predict AM Korin engine component replacement activities that often suffer damage by analyzing based on historical data of damage to these components as well as knowing the optimal cost emphasis for each time interval of component replacement.The results of the study showed that one of the optimal replacement intervals was 23 days for sensor components with a replacement cost of Rp. 77. 625,000 which reduces the cost of previous treatments, which is Rp. 99,900,000. Keywords: Age Replacement; Preventive Maintenance; BreakdownAbstrakKelancaran proses produksi PT Nugraha Indah Citarasa Indonesia sering mengalami gangguan karena mesin AM Korin yang bertindak untuk proses filling sering mengalami kerusakan dan menimbulkan keperluan untuk perbaikan komponen yang sangat merugikan bagi perusahaan karena waktu yang hilang untuk produksi akibat breakdown komponen mesin tersebut sehingga menyebabkan production loss. Jadwal preventive maintenance sangat dibutuhkan untuk mencegah kerusakan di masa yang akan datang untuk mengetahui interval waktu perawatan bagi komponen mesin AM Korin sehingga dapat mengeliminasi downtime berdasarkan pemilihan dengan penghematan biaya yang paling minimal. Age Replacement merupakan penggantian pencegahan berdasarkan umur dari komponen dengan mengikuti pola distribusi tertentu. Jadi penggantian pencegahan dilakukan dengan menetapkan kembali interval waktu penggantian pencegahan berikutnya sesuai dengan interval yang telah ditentukan jika terjadi penggantian akibat kerusakan yang terjadi. Metode Age Replacement berfungsi untuk memprediksikan secara akurat kegiatan penggantian komponen mesin AM Korin yang seringkali mengalami kerusakan dengan menganalisa berdasarkan data historis kerusakan komponen tersebut serta mengetahui penekanan biaya optimal untuk setiap interval waktu penggantian komponen. Hasil dari penelitian menunjukkan bahwa salah satu  selang waktu penggantian optimal yaitu selama 23 hari untuk komponen sensor dengan biaya penggantian Rp. 77. 625.000 dimana menekan biaya perawatan sebelumnya yaitu sebesar Rp. 99.900.000.


2020 ◽  
Vol 72 (10) ◽  
pp. 1153-1158 ◽  
Author(s):  
Yafei Deng ◽  
Xiaotao Pan ◽  
Guoxun Zeng ◽  
Jie Liu ◽  
Sinong Xiao ◽  
...  

Purpose This paper aims to improve the tribological properties of aluminum alloys and reduce their wear rate. Design/methodology/approach Carbon is placed in the model at room temperature, pour 680°C of molten aluminum into the pressure chamber, and then pressed it into the mold containing carbon felt through a die casting machine, and waited for it to cool, which used an injection pressure of 52.8 MPa and held the same pressure for 15 s. Findings The result indicated that the mechanical properties of matrix and composite are similar, and the compressive strength of the composite is only 95% of the matrix alloy. However, the composite showed a low friction coefficient, the friction coefficient of Gr/Al composite is only 0.15, which just is two-third than that of the matrix alloy. Similarly, the wear rate of the composite is less than 4% of the matrix. In addition, the composite can avoid severe wear before 200°C, but the matrix alloy only 100°C. Originality/value This material has excellent friction properties and is able to maintain this excellent performance at high temperatures. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2019-0454/


2021 ◽  
Vol 48 (2) ◽  
pp. 156-168
Author(s):  
Melika Tabasi ◽  
Ahmadreza Mehrabian ◽  
Sadaf Sayadi

Abstract Assessing distribution patterns of valuable taxa plays an important role in the biodiversity conservation of these taxa. The genus Crocus L. (Iridaceae) comprises about 100 species that are distributed mainly in the Mediterranean region and western Asia. The present study purposed to assess the distribution patterns of Iranian Crocus species (including C. sativus L. and 8 wild species) and their conservation status in Iran as one of diversity centers of Crocus in the Middle East. A set of geographic distribution data was compiled through field studies, and reviews of herbarium specimens, iNaturalist, and various Flora. Localities were marked on geo-referenced maps (1/106) of Iran using ArcView version 3.2 (Esri, 2000). The distribution patterns of the taxa were mapped per 0.25° × 0.25° universal transverse Mercator grid cells (25 km2 with the exception of boundary area). Based on the species distribution (SDI) (33%) and species specialization (SSI) (44%) indices, those Iranian Crocus species that are threatened are mainly distributed in Irano-Turanian region. The mountainous ecosystems of Almeh and Western Alborz are important distribution centers of these taxa. Iranian Crocus species with SSI < 0.5 (C. almehensis, C. gilanicus, C. michelsonii, and C. caspius) have the highest conservation value.


2011 ◽  
Vol 383-390 ◽  
pp. 707-711
Author(s):  
Hong Yan ◽  
Yong Hu ◽  
Xiao Quan Wu

Magnesium alloys have high specific strength, specific stiffness, excellent thermal conductivity and casting properties, which have a great prospects development in the industry, However, its low plasticity and ductility limited its application. Magnesium matrix composites can effectively improve its performance. Magnesium alloy die-casting is the main forming process, the conventional high-pressure die-casting (HPDC) defects in multi-cavity type, easy to volume gas, non-heat-treated. Compared with HPDC, the rheo-diecasting (RDC) process has been greatly developed for near-net shape components. In this paper, Mg2Si /AM60 composites is fabricated by in-situ synthesis and semi-solid magnesium matrix composites which are rheoformed in the die-casting machine are prepared by mechanical stirring. The results indicate that the microstructure of composites is non-dendritic and Chinese script type Mg2Si are fine distributed. The fundamental morphology of microstructure by HPDC is dendrite and liquid-phase distributed between dendrite irregularly. The RDC samples have close-to-zero porosity, less segregation, the most of semi-solid of microstructure in rheo-diecasting is spherical or as-spherical structure.


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