CAT液壓內部培訓教程(ppt 117頁)

主要內容
Objectives 目標
Power Flow 動力流動
Energy Distribution during Truckloading 9XX 9XX 裝車應用時的能量分配
Focus Primary users of energy 焦點能量的主要使用者
Implement System 工作係統
Terminology
Hydraulic Schematics
Tandem Center Valve(Open Center at Cat)
627 G – Implement SystemTandem Center – Interrupted Series
980H Implement Schematic Tandem Center (open) Interrupted Series
988H Implement SchematicTandem (Open) Center Interrupted Series
Tandem (Open) Center System
Tandem (Open) Center Hydraulic System開芯式液壓係統
Valve Hardware閥硬件
988H Tilt Stem Characteristics
988H Lift Stem Characteristics
Pump Hardware Gear Pump
Pump HardwareVane Pump
Pump HardwarePiston Pump
WHERE
Examine actual machine裝載機現場調查
Work at Board 白板展示
Speed ControlFill in chart for a light load and a heavy load速度控製完成輕載及重載圖表
Force Control Fill in chart for a light load and a heavy load力的控製完成輕載及重載圖表
Basic Hydraulic Equations 基本液壓公式
Basic Force Equations 基本的力的計算公式
Basic Force Equations for hydraulic components 液壓件的基本力的計算公式
Summary
Form small teams to work problemsNeed to stagger groups to work on machine tests分成小組解決問題需要交叉小組進行整車測試
Fundamentals – Open Center SystemsExercise 基礎知識-開芯式係統練習
Fundamentals – Open Center Systems基礎知識-開芯式係統
Machine Tests整車測試
Machine Tests 整車測試
Load Sensing 加載敏感的
Efficiency 效率
Modifications to go from Open Center Hydraulic System toClosed Center Hydraulic System開芯式係統到閉芯式係統的變更
Pump Controls – High Pressure Cut Off泵控製-高壓截止
High Pressure Cut Off 高壓截止
Pump Controls – Load Sensing泵控製 – 負載敏感的
Load Sensing Control 載荷敏感控製
Physical Locations of Controls
Vickers Load Sensing Compensator and Pressure Limiter
Sample System
System in Neutral
Variable Pump – Neutral ModeLoad Sensing Spool MetersPump near 0 – has sufficient flow to compensate for leakage and maintain output = margin
System Actuated
Variable Pump – Actuated Mode Load Sensing Spool MetersPump at displacement needed to provide sufficient flow to maintain pressure drop from pump to signal (cylinder) output pressure = margin plus cylinder
System at High Pressure Cut
Variable Pump – Pressure Limit Mode Pressure Cut off Spool MetersPump near 0 – has sufficient flow to compensate for leakage and maintain output = high pressure cut pressure
Pump Controls627H Tier 4 Interim
Pump Controls – 980H InterimPump Discharge sent to control piston
Pump Controls – 988H Electronic Pump Control – no signal pressure Pilot Pressure sent to control spool
How do we generate the loadsensing signal?
Signal Generation 信號的產生
Work at White Board
627 Tier 4H Interim
980 Closed Center ValveParallel Circuit
Fundamentals – Closed Center Systems基礎知識-閉芯式係統
Pressure Compensation
980H Interim Closed Center LS - Post CompensationValves in Neutral
980H Interim Closed Center LS - Post CompensationShifted Valves
MG Closed Center LS - Post CompensationValves in Neutral
MG Closed Center LS - Post CompensationValve Shifted
Load Cases
980H Interim Closed Center LS - Post CompensationCase 1 Demand 100 lpm in both circuits
980H Interim Closed Center LS - Post CompensationCase 2 Demand 200 lpm in both circuits
980H Interim Closed Center LS - Post CompensationCase 3 Demand 100 lpm in both circuits
980H Interim Closed Center LS - Post CompensationCase 4 Demand 200 lpm in both circuits
980H Interim Closed Center LS - Post CompensationCase 5 Demand 100 lpm in both circuits, one circuit stalled, one resistive
980H Interim Closed Center LS - Post CompensationCase 6 Demand 100 lpm in both circuits, one circuit stalled, one overrunning
What is Pressure Compensation and What are the Advantages?
Proportional Priority Pressure Compensationor Post Pressure Compensation
Closed Center LS - Post Compensation
Fundamentals – Pressure Compensation基礎知識-閉芯式係統 Needs edited
Ride Control System
Simplest Ride Control
Additional valving for ride control
Equations
Fundamentals – Ride Control

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