DAFTAR ISI HALAMAN JUDUL ........................................................................................ i LEMBAR JUDUL ............................................................................................ ii LEMBAR NOMOR PENGESAHAN .............................................................. iii LEMBAR PENGESAHAN.............................................................................. iv MOTTO ........................................................................................................... v LEMBAR PERSEMBAHAN........................................................................... vi LEMBAR PERNYATAAN ............................................................................ vii KATA PENGANTAR ................................................................................... viii ABSTRACT ....................................................................................................... x INTISARI ........................................................................................................ xi DAFTAR ISI .................................................................................................. xii DAFTAR TABEL .......................................................................................... xv DAFTAR GAMBAR ..................................................................................... xvi DAFTAR LAMPIRAN ................................................................................... xx
BAB I. PENDAHULUAN 1.1 Latar Belakang .......................................................................................... 1 1.2 Tujuan ....................................................................................................... 3 1.3 Batasan Masalah ....................................................................................... 3 1.4 Metode Penelitian...................................................................................... 4 1.5 Sistematika Penulisan ............................................................................... 5
BAB II. LANDASAN TEORI 2.1 Pengertian Main Control Valve ................................................................. 6 2.2 Fungsi Valve pada Main Control Valve ..................................................... 7 2.2.1Pressure Control Valve ....................................................................... 8 2.2.1.1 Fungsi Pressure Control Valve .............................................. 8 2.2.1.2 Tipe Limit Pressure ............................................................. 10 2.2.1.3 Fenomena penting ............................................................... 12 2.2.2 Directional Control Valve ................................................................ 15 xii
2.2.2.1 Check Valve ......................................................................... 16 2.2.2.2 Spool Valve .......................................................................... 18 1.1 Jenis-jenis directional control valve ............................... 21 1.2 Jenis-jenis spool valve berdasarkan jumlah posisi dan koneksi .................................................................... 22 2.2.3 Volume Control Valve ..................................................................... 26 2.3 Cara Kerja Main Control Valve .............................................................. 28 2.4 Spesifikasi Main Control Valve ............................................................... 29 2.5 Letak Main Control Valve ....................................................................... 30 2.6 Komponen ............................................................................................... 31 2.6.1 Housing ........................................................................................... 31 2.6.2 Spool Valve ...................................................................................... 34 2.6.3 Main Relief Valve ............................................................................ 38 2.6.4 Overload Relief Valve ...................................................................... 40 2.6.5 Make Up Valve ................................................................................ 43
BAB III. ANALISA CYLINDER DRIFT SERTA MALFUNGSI PADA MAIN CONTROL VALVE 3.1 Latar Belakang Masalah......................................................................... 47 3.2 Diagram Alir Penelitian .......................................................................... 48 3.3 Troubleshooting ....................................................................................... 49 1.Pemeriksaan actuator ....................................................................... 49 2. Pemeriksaan hose dan pipe .............................................................. 50 3. Pemeriksaan hydraulic pump ........................................................... 53 4. Pemeriksaan main control valve ...................................................... 55 5. Pemeriksaan engine ......................................................................... 62 6. Pemeriksaan control lever ............................................................... 62
BAB IV. ANALISA KERUSAKAN MAIN CONTROL VALVE 4.1 Pembahasan ............................................................................................ 63 4.1.1 Penyebab Cylinder Drift ................................................................. 63
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4.1.2 Analisa Kerusakan Overload Relief Valve ..................................... 65 4.1.3 Pembahasan Scratch dan Sumber Suara Mendesis ...................... 66 4.1.4 Analisa Penyebab Scratch pada Poppet ......................................... 67 4.2 Solusi dan Penanganan ........................................................................... 72 4.3 Estimasi Dampak .................................................................................... 74
BAB V. PENUTUP 5.1 Kesimpulan.............................................................................................. 89 5.2 Saran........................................................................................................ 90
DAFTAR PUSTAKA .................................................................................... 91
LAMPIRAN .................................................................................................. 92
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DAFTAR TABEL
Tabel 2.1 Kelebihan dan kekurangan direct acting relief valve ....................... 10 Tabel 2.2 Kelebihan dan kekurangan pilot operated relief valve ..................... 12 Tabel 2.3 Perbedaan main relief valve dan overload relief valve ..................... 42 Tabel 3.1 Perawatan hose ............................................................................... 51 Tabel 3.2 Perawatan pipe ............................................................................... 52 Tabel 3.3 Fungsi main control valve (kanan bawah) ....................................... 56 Tabel 3.4 Fungsi main control valve (tengah atas) .......................................... 56 Tabel 3.5 Fungsi main control valve (kiri bawah) ........................................... 57 Tabel 3.6 Adjustment overload relief valve ..................................................... 59 Tabel 4.1 Brand name of hydraulic oil ........................................................... 67 Tabel 4.2 Hydraulic oil sample....................................................................... 68 Tabel 4.3 Standar viskositas hydraulic oil sample........................................... 69 Tabel 4.4 Kontaminasi hydraulic oil sample ................................................... 70 Tabel 4.5 Standar kontaminasi hydraulic oil sample ....................................... 70 Tabel 4.6 Nilai Total Acid Number (TAN) ..................................................... 71 Tabel 4.7 Standar kontaminasi hydraulic oil sample ....................................... 71 Tabel 4.8 Nilai milipore (mg/ml) .................................................................... 71 Tabel 4.9 Standar milipore (mg/ml) ................................................................ 72 Tabel 4.10 Monthly availability report EX 269 (Maret 2014) ......................... 80 Tabel 4.11 Monthly availability report EX 269 (Maret 2014) ......................... 80 Tabel 4.12 Breakdown monthly availability report (Maret 2014) EX 269 (Maret 2014) ................................................................... 80 Tabel 4.13 Perbandingan monthly availability Maret 2014 ............................. 83 Tabel 4.14 Monthly availability report EX 269 (Mei 2014) ............................ 84 Tabel 4.15 Monthly availability report EX 269 (Mei 2014) ............................ 84 Tabel 4.16 Breakdown monthly availability report (Mei 2014) EX 269 (Mei 2014) ...................................................................... 84 Tabel 4.17 Perbandingan monthly availability Maret 2014 ............................. 88
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DAFTAR GAMBAR
Gambar2.1 Siklus pemindahan tenaga dari prime mover hingga actuator ........ 7 Gambar2.2 Main control valve ........................................................................ 7 Gambar2.3 Ilustrasi pressure control valve sebagai reducing valve.................. 8 Gambar 2.4 Simbol reducing valve .................................................................. 8 Gambar 2.5 Ilustrasi prinsip kerja sederhana pressure control valve ................ 9 Gambar 2.6 Ilustrasi cara kerja relief valve ...................................................... 9 Gambar 2.7 Cara kerja direct acting relief valve ............................................ 10 Gambar 2.8 Ilustrasi cara kerja pilot operate relief valve ............................... 11 Gambar 2.9 Ilustrasi cracking pressure.......................................................... 12 Gambar 2.10 Ilustrasi cracking pressure ketika terdapat beban ...................... 13 Gambar 2.11 Ilustrasi full flow pressure ........................................................ 13 Gambar 2.12 Ilustrasi full flow pressure ketika terdapat beban....................... 13 Gambar 2.13 Ilustrasi grafik oil relief pressure control valve......................... 14 Gambar 2.14 Ilustrasi proses oil relief pressure control valve ........................ 14 Gambar 2.15 Ilustrasi polisi lalu lintas sebagai pengatur jalur lalu lintas ........ 15 Gambar 2.16 Ilustrasi check valve ................................................................. 16 Gambar 2.17 Ilustrasi check valve yang memiliki fungsi sama dengan rambu lalu lintas ...................................................................... 16 Gambar 2.18 Simple check valve dengan orifice ............................................ 17 Gambar 2.19 Pilot operated check valve – pilot to open check valve .............. 17 Gambar 2.20 Pilot operated check valve – pilot to close check valve ............. 18 Gambar 2.21 Ilustrasi directional control valve ............................................. 18 Gambar 2.22 Ilustrasi directional control valve pada posisi netral ................. 19 Gambar 2.23 Ilustrasi directional control valve pada posisi kiri ..................... 19 Gambar 2.24 Ilustrasi directional control valve pada posisi kanan ................. 20 Gambar 2.25 Pembagian fungsi directional control valve .............................. 20 Gambar 2.26 Ilustrasi directional control valve – open center ....................... 21 Gambar 2.27 Ilustrasi directional control valve – close center ....................... 22 Gambar 2.28 Ilustrasi spool valve 2 posisi 3 koneksi ..................................... 22
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Gambar 2.29 Ilustrasi spool valve 2 posisi 4 koneksi ..................................... 23 Gambar 2.30 Ilustrasi spool valve 2 posisi 4 koneksi (solenoid controlled atau spring return (offset)) ....................... 23 Gambar 2.31 Ilustrasi spool valve 3 posisi4 koneksi (spring centered valve atau double solenoid controlled) ........... 23 Gambar 2.32 Ilustrasi spool valve 3 posisi 4 koneksi (lever controlled atau detended) ............................................... 24 Gambar 2.33 Ilustrasi spool valve 3 posisi 4 koneksi (spring centered) ..................................................................... 24 Gambar 2.34 Ilustrasi spool valve 2 posisi 4 koneksi (spring return) ......................................................................... 24 Gambar 2.35 Ilustrasi spool valve 3 posisi 4 koneksi (double air pilot)...................................................................... 25 Gambar 2.36 Ilustrasi spool valve 3 posisi 4 koneksi (double hydraulic pilot) ........................................................... 25 Gambar 2.37 Spool valve pada diagram hydraulic system dari excavator EX 2500-6 ............................................................... 26 Gambar 2.38 Ilustrasi volume control valve ................................................... 27 Gambar 2.39 Ilustrasi cara kerja volume control valve – proportional flow divider ......................................................... 27 Gambar 2.40 Skema cara kerja main control valve ........................................ 28 Gambar 2.41 Foto main control valve ............................................................ 30 Gambar2.42 Denah letak main control valve dari atas................................... 30 Gambar2.43 Denah letak main control valve ................................................ 31 Gambar 2.44 Ilustrasi cutway housing main control valve ............................. 32 Gambar 2.45 Sketch housing main control valve............................................ 32 Gambar 2.46 Housing main control valve Z-axis ........................................... 33 Gambar 2.47 Housing main control valve unit EX ......................................... 34 Gambar 2.48 Ilustrasi spool valve .................................................................. 35 Gambar 2.49 Foto spool valve ....................................................................... 36 Gambar 2.50 Foto spool valve ....................................................................... 36
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Gambar 2.51 Foto spool valve ....................................................................... 36 Gambar 2.52 Foto spool valve ....................................................................... 37 Gambar 2.53 Sketch spool valve .................................................................... 37 Gambar 2.54 Spool valve pada hydraulic diagram EX 2500-6 ....................... 38 Gambar 2.55 Main relief valve pada hydraulic diagram EX 2500-6 ............... 38 Gambar 2.56 Sketch main relief valve ............................................................ 39 Gambar 2.57 Cutway main relief valve .......................................................... 39 Gambar 2.58 Komponen main relief valve ..................................................... 39 Gambar 2.59 Overload relief valve pada hydraulic diagram EX 2500-6 ........ 41 Gambar 2.60 Sketch overload relief valve ...................................................... 41 Gambar 2.61 Komponen overload relief valve ............................................... 42 Gambar 2.62 Cutway overload relief valve .................................................... 42 Gambar 2.63 Make up valve pada hydraulic diagram EX 2500-6 ................... 44 Gambar 2.64 Sketch make up valve ................................................................ 44 Gambar 2.65 Cutway make up valve .............................................................. 45 Gambar 2.66 Bagian-bagian make up valve ................................................... 45
Gambar 3.1 Excavator 2500-6 dengan fleet number EX 269 .......................... 47 Gambar 3.2 Diagram alir penelitian ............................................................... 48 Gambar3.3 Siklus pemindahan tenaga dari prime mover hingga actuator ...... 49 Gambar 3.4 Hydraulic cylinder pada bucket 2500-6 dengan fleet number EX 269 tidak mengalami leakage. .......................... 50 Gambar 3.5 Titik pemeriksaanan pada hose ................................................... 51 Gambar 3.6 Titik pemeriksaanan pada clamp pipe ......................................... 52 Gambar 3.7 Skema sederhana sirkuit hidrolik EX 2500-6 .............................. 53 Gambar 3.8 Skema sederhana sirkuit hidrolik EX 2500-6 .............................. 54 Gambar 3.9 Main control valve pada excavator 2500-6 ................................. 55 Gambar 3.10 Lock nut dan adjusting screw pada overload relief valve........... 58 Gambar 3.11 Arah adjustment adjusting screw pada overload relief valve ..... 59 Gambar 3.12 Overload relief valve yang telah diganti ................................... 60 Gambar 3.13 Make-up valve yang telah diganti ............................................. 61
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Gambar4.1 Ilustrasi cara kerja relief valve ..................................................... 64 Gambar4.2 Foto scratch pada poppet overload relief valve ............................ 65
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DAFTAR LAMPIRAN
Lampiran 1. Safety data sheet SU-459 Hitachi genuine hydraulic oil 46 TP .. 93 Lampiran 2. Hasil pengujian hydraulic oil sample oleh PT Tekenomiks Indonesia.................................................. 96 Lampiran 3. Hydraulic oil temperature histogram EX 269 bulan Maret 2014 ...................................................................... 98 Lampiran 4. Hydraulic oil temperature histogram EX 269 bulan April 2014 ....................................................................... 99 Lampiran 5. Hydraulic oil temperature histogram EX 269 bulan Mei 2014 ....................................................................... 100 Lampiran 6. Monthly availability EX 2500-6 (EX 269) bulan Mei 2014 ...... 101 Lampiran 7. Monthly availability EX 2500-6 (EX 269) bulan Mei 2014 ...... 102
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