05液压系统Hydraulic system.pdf

液压系统 Hydraulic system

目录 Table of contents 1.液压基础知识 Hydraulic basic knowledge z 2.液压元件介绍 The introduction of hydraulic components z 3.挖掘机液压系统 Hydraulic system of excavator z 4.液压管路介绍 The introduction of hydraulic pipe line z 5. 压力测试与调整 Pressure test and adjust z 6. 故障分析与处理 Troubleshooting z

1.1 帕斯卡原理 Pascal’s theorem 1. 处于密闭容器内的液体对施加于它表 面的压力向各个方向等值传递。 Pressure on a confined liquid will exert the same force in all directions equally .

Large area

Load

2.速度的传递按“容积变化相等”的原则 The speed of the load, as it moves, is in direct proportion to the area of it’s cylinder verses the area of the cylinder F. 3.液体的压力由外载荷建立。认为泵一出 油就有压力是错误的。 Fluid pressure is created by external load. No load, no pressure. 4.能量守恒 Conservation of energy

Small area F

Full of oil

F＝p×A P＝v×F

v＝q÷A

F--force p--pressure A--area q--flow P--power v--speed

1.2 液压系统常用线型和符号 Lines and symbols commonly used in hydraulic systems 线型 Lines: 粗实线表示工作管路 Thick solid lines represent work lines 虚线表示控制管路 Broken solid lines represent pilot or drain lines 双点划线表示组合元件 Double dotted lines represent combined elements 有小圆点的相交线表示连接管路 Intersect lines with small dots represent connected lines. 有小圆弧的相交线表示不相交连接管路 Intersecting lines with small circular offset, represent lines or circuits that do not meet

符号 Symbols： P——泵压力油 Pressure oil of pump A、B——油缸或马达的工作油口 The work oil port of cylinder or motor O、T、Dr——油箱 Reservoir

1.3 液压系统的基本构成 Basic composition of the hydraulic system 液压系统由4部分组成： Hydraulic system consist of 4 parts: 液压泵：将机械能转换为液体压力能。 Hydraulic pump: Converts the mechanical energy to hydraulic energy. 执行元件：将液体压力能转换为机械能。例 如油缸、油马达等。 Implement components: Convert the hydraulic energy to mechanical energy. For example cylinder, motor and so on.

1.3 液压系统的基本构成 Basic composition of the hydraulic system 控制元件：各种阀。大致有压力控制阀、流 量控制阀、方向控制阀等。 Control components: Valves. Generally, there are pressure control valves, flow control valves, directional control valve. 辅助元件：油箱、过滤器、管路、接头、密 封、冷却器、蓄能器等等。 Auxiliary components: Hydraulic tank, filters, piping, joints, seals, coolers, accumulators and so on.

1.4 液压元件符号 Symbol of hydraulic components 液压泵 Hydraulic pump:

单向、定排量 One-way, fixed displacement

双向、定排量 Two-way, fixed displacement

单向、变排量 One-way, variable displacement

1.4 液压元件符号 Symbol of hydraulic components 液压阀 Hydraulic valves :

单向阀 One-way valve

溢流阀 Relief valve

梭阀 Shuttle Valve

压力减压阀 Pressure reducing valve

节流阀 Flow Control Valve

电磁阀 Solenoid valve

可变节流阀 Variable Flow Control Valve

截止阀 Shut-off valve

1.4 液压元件符号 Symbol of hydraulic components 液压马达 Hydraulic motor:

单向、定排量 One-way, fixed displacement

双向、定排量 Two-way, fixed displacement

双向、变排量 Two-way, variable displacement

1.4 液压元件符号 Symbol of hydraulic components 液压缸 Hydraulic cylinder :

A

B

双作用液压缸 Double-acting hydraulic cylinder

A

B

单作用液压缸 Single-acting hydraulic cylinder

1.4 液压元件符号 Symbol of hydraulic components 辅助元件 Auxiliary components:

液压油箱 Hydraulic Reservoir

散热器 Cooler

过滤器 Filter

蓄能器 Accumulator

1.5 推荐用液压油 Recommended Hydraulic oil

如果需要额外的信息，请联系柳工总部 Please contact LiuGong Headquarters for additional information. 禁止使用马达润滑油 Use of Motor oil is prohibited.

目录 Table of contents 1.液压基础知识 Hydraulic basic knowledge z 2.液压元件介绍 The introduction of hydraulic components z 3.挖掘机液压系统 Hydraulic system of excavator z 4.液压管路介绍 The introduction of hydraulic pipe line z 5. 压力测试与调整 Pressure test and adjust z 6. 故障分析与处理 Troubleshooting z

主要液压元件 Main hydraulic components

主泵 Main pump

行走马达及减速机 Travel Motor&Reducer

主控阀 Main control valve

回转马达及减速机 Swing Motor&Reducer

先导阀块 手先导阀 行走先导阀 Pilot valve Travel pilot valve Pilot valve block

z

2. 液压元件介绍 The introduction of hydraulic components

2.1 主泵 Main pump 2.2 主控阀 Main control valve 2.3 回转马达及减速机 Swing Motor&Reducer 2.4 行走马达及减速机 Travel Motor&Reducer 2.5 手先导阀 Pilot valve 2.6 行走先导阀 Travel pilot valve 2.7 先导阀块 Pilot valve block

2.1 主泵 (描述) Main pump (description) 该泵由主泵和先导泵构成。主泵是可变排量轴向柱塞泵，他提供高压油给 液压系统。先导泵是定排量齿轮泵，它给控制系统提供先导油。主泵由发动机 通过联轴器驱动，先导泵与主泵的轴直接连接，转速和主泵一致。 This pump is composed of main pump and pilot pump. The main pump is a variable displacement axial plunger pump. It provides high pressure oil for the hydraulic system of excavator. The pilot pump is a fixed displacement gear pump. It supplies oil for the control system. The main pump is driven by the engine through a coupler. The pilot gear pump is connected directly by the drive shaft of the main pump at the same rotate speed.

2.1 主泵 (主要参数) Main pump (main parameters) 条目 Item

单位 unit

型式 Type 主泵 Main pump

923D/925D

Duplex Variable Axial Piston Pump

Duplex Variable Axial Piston Pump

排量 Displacement

cc

108

115

流量 Flow

L/min

2×215

2×230

额定压力 Rated pressure

MPa

34.3

34.3

Gear pump

Gear pump

型式 Type 先导泵 Pilot pump

920D/922D

排量 Displacement

cc

10

10

流量 Flow

L/min

20

20

额定压力 Rated pressure

MPa

3.9

3.9

2.1 主泵(外形) Main pump (shape) 先导泵测压口 The port of pilot pressure test

主泵测压口 The port of main pressure test 左泵 Left pump

适用机型 Models： 920D (Ⅱ) 922D (Ⅱ) 923D (Ⅱ) 925D (Ⅱ)

泄油口 Port for Leakage 泵出油口 Oil outlet

右泵 Right pump

先导泵 Pilot pump

先导压力调整螺钉 Pilot pressure adjust bolt

最小流量调整螺钉 The adjust bolt of min. flow 左泵调节器 Regulator for right pump

最大流量调整螺钉 The adjust bolt of max. flow

电比例减压阀 Solenoid Proportional Reducing Valve

右泵调节器 Regulator for right pump

最小流量调整螺钉 The adjust bolt of min. flow

2.1 主泵(液压回路图) Main pump (Hydraulic schematic ) P1泵调节器 Regulator for P1 pump

电磁比例减压阀 Solenoid Proportional Reducing Valve

适用机型 Models： 920D (Ⅱ) 922D (Ⅱ) 923D (Ⅱ) 925D (Ⅱ)、 925D(Ⅲ)

P2泵调节器 Regulator for P2 pump

Pilot pump P1 pump P2 pump

z

2. 液压元件介绍 The introduction of hydraulic components

2.1 主泵 Main pump 2.2 主控阀 Main control valve 2.3 回转马达及减速机 Swing Motor&Reducer 2.4 行走马达及减速机 Travel Motor&Reducer 2.5 手先导阀 Pilot valve 2.6 行走先导阀 Travel pilot valve 2.7 先导阀块 Pilot valve block

2.2 主控阀(描述) Main control valve (description) 主控阀位于主泵和执行元件（油缸和马达）之间，它控制执行元件的油的 方向和流量。控制阀为液压先导控制、开式负流量控制阀，由九个阀芯组成、 并联的整体式多路换向阀。包含用于控制动臂、斗杆、铲斗、回转、行走、附 属装置的阀芯。控制阀具有动臂上升合流、斗杆合流、斗杆再生、回转优先、 动臂、斗杆锁定、直线行走等功能。 The main control valve is located between the main pump and actuators(all of the cylinders and motors).It controls the oil direction, pressure, and flow rate for all of the actuators. Main control valve is pilot control, open negative flow control, and paralleling monolithic multi-ported directional valve composed of nine spools. It includes spools for the boom，arm，bucket， swing，travel and auxiliary devices. Main control valve has the auxiliary functions for boom raise confluence，arm confluence，arm regeneration， swing priority，boom anti-drift，arm anti-drift and straight travel.

2.2 主控阀(主要参数) Main control valve (main parameters) 条目 Item

单位 unit

920D/922D

923D/925D

主溢流阀压力(标准) Main relief pressure, (standard)

Mpa

31.8

32.2

主溢流阀压力(增压) Main relief pressure, (boost)

Mpa

33.3

34.6

回转压力 Implement circuits

Mpa

25.5

25.5

2.2 主控阀(外形) Main control valve (Shape) 斗杆油口溢流阀 Port relief valve for arm spool

适用机型 Models： 920D(Ⅱ)、 922D(Ⅱ)、 922D(Ⅲ)、 923D(Ⅱ)、 925D(Ⅱ)、925D(Ⅲ)

斗杆2阀芯 2nd arm spool

斗杆锁定阀 Lock valve for boom

铲斗阀芯 Bucket spool

斗杆1阀芯 1st arm spool

动臂1阀芯 1st boom spool

动臂2阀芯 2nd boom spool

铲斗油口溢流阀 Port relief valve for bucket spool

回转阀芯 Swing spool

动臂油口溢流阀 Port relief valve for boom spool

主溢流阀 Main relief valve

动臂锁定阀 Lock valve for boom

直线行走阀 Straight travel valve

左行走阀芯 Left travel spool

右行走阀芯 Right travel spool

备用油口溢流阀 Port relief valve for option spool

备用阀芯 Option spool

适用机型 Models：

2.2 主控阀(外形) Main control valve (Shape) C2

备用提升 阀/LCo

HV

HV

C1

920D(Ⅱ)、 922D(Ⅱ)、 922D(Ⅲ)、 923D(Ⅱ)、 925D(Ⅱ)、925D(Ⅲ)

动臂合流单 向阀/CCb

斗杆1提 升阀 /LCa1

CP2 负反馈 油口FR 负反馈 油口FL

动臂1提 升阀 /LCb1

铲斗提升 阀/LCk

斗杆2提 升阀 /LCa2

CSp

CSp

主溢流阀单向阀 /CMR1&CMR2

2.2 主控阀(液压回路图) Main control valve (Hydraulic schematic )

适用机型 Models： 920D(Ⅱ)、 922D(Ⅱ)、 922D(Ⅲ)、 923D(Ⅱ)、 925D(Ⅱ)、925D(Ⅲ)

z

2. 液压元件介绍 The introduction of hydraulic components

2.1 主泵 Main pump 2.2 主控阀 Main control valve 2.3 回转马达及减速机 Swing Motor&Reducer 2.4 行走马达及减速机 Travel Motor&Reducer 2.5 手先导阀 Pilot valve 2.6 行走先导阀 Travel pilot valve 2.7 先导阀块 Pilot valve block

2.3 回转马达及减速机(描述) Swing motor & reduction gear (description) 回转马达及减速机由液压马达和减速机组成。它带动挖掘机的上 部机构回转。 The swing motor&reducer consists of a hydraulic motor and a reduction gear.It rotates the upper structure of excavator.

920D/922D

923D/925D

2.3 回转马达及减速机(外形) Swing motor & reduction gear (shape) 润滑油加注口 Port for lubricating oil

溢流阀 Relief valve

油标尺 Oil dipstick

适用机型 Models： 920D(Ⅱ) 922D(Ⅱ) 922D(Ⅲ)

测压口 Port for pressure test 防反转阀 Anti-reversion valve 主压力口 Port for main pressure 回转制动延时阀 Time-delay valve for braking

回转减速机 Swing reduction gear

2.3 回转马达及减速机(外形) Swing motor & reduction gear (shape)

适用机型 Models： 923D(Ⅱ) 925D(Ⅱ) 925D(Ⅲ)

溢流阀 Relief valve 测压口 Port for pressure test 润滑油加注口 Port for lubricating oil

油标尺 Oil dipstick 主压力口 Port for main pressure

防反转阀 Anti-reversion valve

回转减速机 Swing reduction gear

2.3 回转马达及减速机(液压回路图)

Swing motor & reduction gear (hydraulic schematic)

适用机型 Models： 920D(Ⅱ)、 922D(Ⅱ)、 922D(Ⅲ)、 923D(Ⅱ)、 925D(Ⅱ)、925D(Ⅲ)

z

2. 液压元件介绍 The introduction of hydraulic components

2.1 主泵 Main pump 2.2 主控阀 Main control valve 2.3 回转马达及减速机 Swing Motor&Reducer 2.4 行走马达及减速机 Travel Motor&Reducer 2.5 手先导阀 Pilot valve 2.6 行走先导阀 Travel pilot valve 2.7 先导阀块 Pilot valve block

2.4 行走马达及减速机(描述) Travel motor & reduction gear (description) 行走马达及减速机由液压马达和减速机组成。它带动挖掘机的上 部机构回转。它用来控制机器向前、向后、左转、右转运动。行 走速度由行走速度控制开关控制。它有两档速度：低速和高速。 它不能从高速档自动调到低速档。 The Travel motor & reducer consists of a hydraulic motor and a reduction gear. It is used to control the forward, backward, left turn and right turn operation of the machine.The travel speed can be controled by travel speed control switch.There are two speed positons:Low Speed and High Speed. It does not automatically downshift.

2.4 行走马达及减速机(外形) Travel motor & reduction gear (Shape)

适用机型 Models： 920D(Ⅱ)、 922D(Ⅱ)、 922D(Ⅲ)、 923D(Ⅱ)、 925D(Ⅱ)、925D(Ⅲ)

平衡阀 Balance valve 安全阀 Relief valve 先导油口/控制行走变速 Pilot Port/control travel speed

减速机 Travel reduction gear

安全阀 Relief valve 测压口 Port for pressure test

泄油口 Port for Leakage

注油口 Refill oil

主压力油口 Port for main pressure

油位线 Oil level mark

泄油口 Port for Leakage

放油口 Oil drain plug

适用机型 Models：

2.4 行走马达及减速机(液压回路图) Travel motor & reduction gear (hydraulic schematic )

920D(Ⅱ)、 922D(Ⅱ)、 922D(Ⅲ)、 923D(Ⅱ)、 925D(Ⅱ)、925D(Ⅲ)

安全阀 Relief valve

平衡阀 Balance valve

z

2. 液压元件介绍 The introduction of hydraulic components

2.1 主泵 Main pump 2.2 主控阀 Main control valve 2.3 回转马达及减速机 Swing Motor&Reducer 2.4 行走马达及减速机 Travel Motor&Reducer 2.5 手先导阀 Pilot valve 2.6 行走先导阀 Travel pilot valve 2.7 先导阀块 Pilot valve block

2.5 手先导阀(描述) Pilot valve (description) 手先导阀用于控制执行元件的速度和操作。一个位于驾驶室内座 椅左侧，一个位于右侧。在标准模式下，左侧先导阀控制回转、 斗杆和喇叭，右侧先导阀控制动臂、铲斗和增压。 The pilot control valve is used to control implements speed and operation. One is installed on the left side of operator seat in the cab, and another is installed on the right side. The left one controls swing, arm and horn. The right one controls boom and bucket and power boost in standard mode.

2.5 手先导阀(液压回路图) Pilot valve (Hydraulic schematic )

z

2. 液压元件介绍 The introduction of hydraulic components

2.1 主泵 Main pump 2.2 主控阀 Main control valve 2.3 回转马达及减速机 Swing Motor&Reducer 2.4 行走马达及减速机 Travel Motor&Reducer 2.5 手先导阀 Pilot valve 2.6 行走先导阀 Travel pilot valve 2.7 先导阀块 Pilot valve block

2.6 行走先导阀(描述) Travel pilot valve (Description) 行走先导阀提供先导油至主控阀上的行走阀芯，控制整机前进、 后退、左转、右转。它也能控制行走系统平稳的运行。 The travel pilot valve supplies pilot oil for the travel spools of the main control valve to control the forward, backward, left turn and right turn operation of the machine. It also has hydraulic dampeners to smooth operation of the travel system.

2.6 行走先导阀(液压回路图) Travel pilot valve (Hydraulic schematic )

z

2. 液压元件介绍 The introduction of hydraulic components

2.1 主泵 Main pump 2.2 主控阀 Main control valve 2.3 回转马达及减速机 Swing Motor&Reducer 2.4 行走马达及减速机 Travel Motor&Reducer 2.5 手先导阀 Pilot valve 2.6 行走先导阀 Travel pilot valve 2.7 先导阀块 Pilot valve block

2.7 先导阀块(描述) Pilot valve block (description)

适用机型 Models： 920D(Ⅱ)、 922D(Ⅱ)、 922D(Ⅲ)、 923D(Ⅱ)、 925D(Ⅱ)、925D(Ⅲ)

先导油流过先导阀块去遥控先导控制阀。先导阀块上有三个电磁 阀，分别控制液压先导锁定、二速行走、主溢流阀增压。 Pilot oil goes through the pilot valve block to remote pilot control valve. There are three solenoid valves which control pilot lock, two speed travel. and power boost of main relief valve.

液压先导切断 Pilot lock 二速行走 Two speed travel 增压 Power boost

2.7 先导阀块(液压回路图) Pilot valve block (Hydraulic schematic )

液压先导锁定 二速行走 Pilot Lock Two Speed Travel

增压 Power Boost

目录 Table of contents 1.液压基础知识 Hydraulic basic knowledge z 2.液压元件介绍 The introduction of hydraulic components z 3.挖掘机液压系统 Hydraulic system of excavator z 4.液压管路介绍 The introduction of hydraulic pipe line z 5. 压力测试与调整 Pressure test and adjust z 6. 故障分析与处理 Troubleshooting z

z

3.挖掘机液压系统 Hydraulic system of excavator

§ 3.1 液压系统参数 Hydraulic system parameters § 3.2 液压系统传动简图 Drive diagram of hydraulic system § 3.3 液压系统回路图 Hydraulic system schematic 3.3.1 负流量控制系统 Negative flow control system 3.3.2 动臂上升 Boom raise 3.3.3 动臂下降 Boom lower 3.3.4 斗杆伸 Arm out 3.3.5 斗杆收 (带再生功能) Arm In (with regeneration) 3.3.6 斗杆收 (不带再生功能) Arm In (without regeneration) 3.3.7 铲斗伸 Bucket in 3.3.8 铲斗收 Bucket out 3.3.9 左回转 Swing left 3.3.10 右回转 Swing right 3.3.11 前进(高速) Forward travel (high speed) 3.3.12 后退( 低速) Backward travel (low speed) 3.3.13 直线行走 Straight travel

§ 3.1 液压系统参数 Hydraulic system parameters 条目 Item

单位 Unit

920D/922D

923D/925D

Double Variable Axial Piston Pump

Double Variable Axial Piston Pump

cc

108

115

1

主泵型式 Main pump type

2

主泵排量Main pump displacement

3

主泵总流量Main pump total flow

L/min

2×215

2×230

4

主溢流阀压力Relief pressure, main

MPa

31.8

32.2

5

增压溢流阀压力Relief pressure, boost

MPa

33.3

34.6

6

回转回路压力Swing Circuit pressure

MPa

25.5

25.5

7

行走回路压力Travel circuit Pressure

MPa

31.8

31.8

8

动臂大/小腔溢流阀压力Boom Head/Rod Relief Pressure

MPa

36.3/36.3

36.6/36.6

9

斗杆大/小腔溢流阀压力Arm Head/Rod Relief Pressure

MPa

37.2/37.2

36.6/37.2

10

铲斗大/小腔溢流阀压力Bucket Head/Rod Relief Pressure

MPa

35.3/36.3

36.6/37.2

11

备用溢流压力Option Relief Pressure

Mpa

19.6

19.6

§ 3.1 液压系统参数 Hydraulic system parameters 12

先导泵型式 Pilot pump type

齿轮泵 Gear pump

齿轮泵 Gear pump

13

先导泵排量Pilot pumpdisplacement

cc

10

10

14

先导泵流量Pilot pump flow

L/min

20

20

15

先导压力Pilot pressure

MPa

3.9

3.9

16

动臂油缸(缸径×杆径×行程 –最小安 装距 ) boom cylinder (Bore×rod×Stroke -Min. Installation Dimension )

mm

120×85×1187-1794

φ125×φ90×1350×1950

17

斗杆油缸(缸径×杆径×行程 –最小安 装距 ) arm cylinder (Bore×rod×Stroke -Min. Installation Dimension )

mm

135×95×1450-2063

φ140×φ105×1610×223 5

18

铲斗油缸(缸径×杆径×行程 –最小安 装距 ) bucket cylinder (Bore×rod×Stroke -Min. Installation Dimension )

mm

120×85×1058-1593

φ130×φ90×1075×1665

19

液压油(油箱/系统)hydraulic oil (tank/system)

L

230/330

230/330

20

回转马达齿轮油Swing motor gear oil

L

3.4

4.4

21

行走马达齿轮油Drive motor gear oil

L

5.5*2

5.5*2

§ 3.2 液压系统传动简图 Drive diagram of hydraulic system 驱动 柴油机

Drive

控制油 先导泵

Control oil

Pilot pump

Engine

驱动 Drive

Work oil

Work pump

Implement work

Control

Carry out

司机 Driver

控制油 Control oil 工作油 主控阀 Work oil 马达 Main valve

实现

工作装置工作

先导阀 Pilot valve

工作油 工作泵

操纵

Motor

工作油

实现

Work oil

Carry out

油缸

旋转、行走

Cylinder

Swing、Travel

3.3 液压系统回路图 Hydraulic system schematic 3

3.3.1 负流量控制系统 Negative Flow Control System

BOOM RAISE 3.3.2 动臂上升Boom Raise

BOOM LOWER 3.3.3 动臂下降Boom Lower

ARM OUT

3.3.4 斗杆伸Arm Out

ARM IN WITH REGENERATION

3.3.5 斗杆收(带再生功能)Arm In (With Regeneration)

3.3.6 斗杆收(不带再生功能) WITHOUT ArmARMREGENERATION InIN(Without Regeneration)

BUCKET IN 3.3.7 铲斗收 Bucket In

3.3.8 BUCKET 铲斗伸Bucket Out OUT

M

SWING LEFT 3.3.9 左回转Swing Left

3.3.10右回转Swing SWING RIGHT Right

3.3.11 前进(高速) Forward Travel (High Speed) FORWARD TRAVLE(HIGH SPEED)

3.3.12 后退(低速) Backward Travel (Low Speed) BACKWARD TRAVLE(LOW SPEED)

3.3.13 直线行走Straight Travel STRAIGHT TRAVLE

目录 Table of contents 1.液压基础知识 Hydraulic basic knowledge z 2.液压元件介绍 The introduction of hydraulic components z 3.挖掘机液压系统 Hydraulic system of excavator z 4.液压管路介绍 The introduction of hydraulic pipe line z 5. 压力测试与调整 Pressure test and adjust z 6. 故障分析与处理 Troubleshooting z

4.1 主泵管路 Main pump piping 泄油管Case Drain hose

适用机型 Models： 920D(Ⅱ)、 922D(Ⅱ)、 923D(Ⅱ)、 925D(Ⅱ)、925D(Ⅲ)

压力传感器 Pressure sensor

工作管路 Working hose 电比例减压阀 Solenoid Proportional Reducing Valve

吸油钢管 Oil inlet tube

液压油温传感器 Sensor for hydraulic oil temperature

4.2 回转马达管路 Swing Motor Piping

适用机型 Models： 920D(Ⅱ)、 922D(Ⅱ)、922D(Ⅲ)

工作油管 Working hose 补油管 Make up oil inlet

回转压力测压点 Swing pressure test point

润滑油加注口 Port for lubricating oil

泄油管 Case Drain hose

回转溢流阀 Swing relief valve

油标尺 Oil dipstick

4.2 回转马达管路 Swing Motor Piping 泄油管 Case Drain hose

回转溢流阀 Swing relief valve

适用机型 Models： 923D(Ⅱ)、 925D(Ⅱ)、925D(Ⅲ)

补油管 Make up oil inlet

润滑油加注口 Port for lubricating oil

油标尺 Oil dipstick 回转压力测压点 Swing pressure test point 工作油管 Working hose

4.3 先导液压管路(先导阀块)

适用机型 Models： 922D(Ⅲ)

Pilot hydraulic pipe line(Pilot valve block)

蓄能器 Accumulator 先导溢流阀 Pilot relief valve 压力传感器 Pressure sensor

先导压力测试点 Pilot pressure test point 先导滤芯 Pilot filter

4.3 先导液压管路(先导阀块)

适用机型 Models：

Pilot hydraulic pipe line(Pilot valve block)

920D(Ⅱ)、 922D(Ⅱ)、 923D(Ⅱ)、 925D(Ⅱ)、925D(Ⅲ)

蓄能器 Accumulator 先导压力测压点 Pilot pressure test point 压力传感器 Pressure sensor 先导滤芯 Pilot filter

目录 Table of contents 1.液压基础知识 Hydraulic basic knowledge z 2.液压元件介绍 The introduction of hydraulic components z 3.挖掘机液压系统 Hydraulic system of excavator z 4.液压管路介绍 The introduction of hydraulic pipe line z 5. 压力测试与调整 Pressure test and adjust z 6. 故障分析与处理 Troubleshooting z

5.1 系统压力测试 System pressure test P2

P1

a2

a1

适用机型 Models： 920D(Ⅱ)、 922D(Ⅱ)、 922D(Ⅲ)、 923D(Ⅱ)、 925D(Ⅱ)、925D(Ⅲ)

P1、P2口压力测试:(压力测试口a1、a2 ,规格：G1/4) Port P1、P2 pressure test:(pressure test ports a1、a2 dimension:G1/4) 1、用扳手拧开图中a1、a2处的螺塞并连上测压接头和压力表(压 力表量程0～70MPa)； Remove the plug a1/a2 in the illustration with a spanner and connects with a pressure testing joint and a pressure gauge(with a range of 0~70MPa); 2、启动发动机，慢慢的操作挖掘机使油温增高到50±5℃左 右，然后读压力表的读数； Start engine, Slowly operate the excavator to raise the hydraulic oil temoerature to 50±5℃;then read the data from the gauge; 3、拧下压力表和测压接头，用16Nm的扭矩拧紧螺塞。 Remove pressure gauge and pressure testing joint.Tighten the plugs to a torque of 16Nm.

5.2 系统压力调整 System pressure adjust

适用机型 Models： 920D(Ⅱ)、 922D(Ⅱ)、 922D(Ⅲ)、 923D(Ⅱ)、 925D(Ⅱ)、925D(Ⅲ)

1、启动发动机，缓慢提高发动机转速到最高转速； Start the engine, increase it‘s rotating speed slowly to full speed ； 2、调整挖掘机上的显示器功能，使之位于检测左泵和右泵压力的状态 ； Set the excavator monitor to the function of cheking the left and right pump pressure; 3、放下先导操作手柄，操作工作装置使液压油温升高到50±5℃，然后操作动臂或斗杆伸出到行程 末端位置，使安全阀打开。此时的压力值应为31.8~32.8MPa，再按下位于右操作杆上的按钮，压力 值应为33.3~34.3MPa； Turn on the pilot cutoff lever, operate the work implements to let the hydraulic oil temperature raises to 50±5℃, then operate the boom up or arm to extreme position to make the main relief valve open. At the moment the pressure value should be 31.8~32.8MPa, then press the burst button located on the right joystick, the pressure value should be 33.3~34.3MPa； 4、如果压力值不在以上的范围之内，我们需要按照以下的步骤进行调整： If the pressure values are not in the arrange above, we need to adjust them as following procedure: (1) 用开口为30mm的开口扳手松开序号3锁紧螺母； Loose locknut number 3 with open-end wrench(30mm);

5.2 系统压力调整 System pressure adjust

适用机型 Models： 920D(Ⅱ)、 922D(Ⅱ)、 922D(Ⅲ)、 923D(Ⅱ)、 925D(Ⅱ)、925D(Ⅲ)

(2) 按下右操作杆上的按钮，用6mm的内六角扳手向内或向外旋转序号4零件，同时观察显示器上的 压力值，当达到33.3-34.3MPa时，停止旋转序号4零件并拧紧序号3零件，松开右操作杆上的按钮； Press the burst button located on the right joystick ，turn number 4 slightly inwards or outwards slowly with inner hexagon spanner(6mm) and check the pressure value in the monitor.Stop turning number 4 when the pressure value reaches to 33.3-34.3MPa, then tighten number 3， loose the burst button located on the right joystick ; (3)用开口为22mm的开口扳手逆时针松开序号5锁紧螺母，用6mm的内六角扳手向内或向外旋转序号 4零件，同时观察显示器上的压力值，当达到31.8-32.8MPa时，停止旋转序号4零件并拧紧序号5零 件。 Loose locknut number 5 with open-end wrench(22mm) in anticlockwise direction.Turn number 4 inwards or outwards slowly with hexagon spanner(6mm) and check the pressure value in the monitor. Stop turning number 4 and tighten number 5 when the pressure value reaches to 31.8~32.8MPa. 主安全阀 Main relief valve

5.3 先导压力测试 Pilot pressure test

适用机型 Models： 920D(Ⅱ)、 922D(Ⅱ)、 923D(Ⅱ)、 925D(Ⅱ)、925D(Ⅲ)

先导压力测试：压力测试口a3，规格G1/4 Pilot pressure test and adjust:(pressure test port a3 dimension:G1/4) 1、用扳手拧开图中a3（序号466）处的螺塞并连上测压接 头和压力表(压力表量程0～6MPa); Remove the plug a3（number466） in the illustration with a pressure testing joint and a spanner and connects with a pressure gauge(with a range of 0~6MPa); 2、启动发动机，慢慢的操作挖掘机使油温增高到50±5℃ 左右，然后读压力表的读数； Start engine, Slowly operate the excavator to raise the hydraulic oil temperature to 50±5℃;

先导泵测压口a3 The port of pilot pressure test a3

3、在发动机转速在最高转速时，看压力表的读数，数值应 在3.9~4.1MPa之间。 Set the engine speed to full speed , check the pressure gauge,the value should be between 3.9~4.1MPa.

5.3 先导压力测试 Pilot pressure test

适用机型 Models： 920D(Ⅱ)、 922D(Ⅱ)、 922D(Ⅲ)、 923D(Ⅱ)、 925D(Ⅱ)、925D(Ⅲ)

1、用手拧开图中序号2或序号4处的螺塞并连上压力表(压力表量 程0～6MPa); Remove the plug number 2 or 4 in the illustration by hand and connects with a pressure gauge(with a range of 0~6MPa); 2、启动发动机，慢慢的操作挖掘机使油温增高到50±5℃左右， 然后读压力表的读数； Start engine, Slowly operate the excavator to raise the hydraulic oil temperature to 50±5℃; 3、在发动机转速在最高转速时，看压力表的读数，数值应在 3.9~4.1MPa之间。 Set the engine speed to full speed, check the pressure gauge,the value should be between 3.9~4.1MPa.

5.4 先导压力调整 Pilot pressure adjust

适用机型 Models： 920D(Ⅱ)、 922D(Ⅱ)、 923D(Ⅱ)、 925D(Ⅱ)、925D(Ⅲ)

如果先导压力值不正确，请按以下步骤进行调整： If the Pilot pressure pressure value is incorrect, adjust it as following procedure: (1)、用开口为22mm的开口扳手松开图中序号312锁紧螺 母，用6mm的内六角扳手拧紧序号311螺钉，顺时针方向压 力升高，逆时针方向压力降低,当压力值达到3.9~4.1MPa 时，上紧锁紧螺母312，压力调整完成； Loose locknut 312 with open-end wrench(22mm)as shown in the illustration. Tighten screw 311 by inner hexagon spanner(6mm). The pressure will increase when rotate in clockwise direction and decrease when rotate in anticlockwise direction. Tighten locknut 312 when the pressure value reaches to 3.9~4.1MPa. After that, pressure adjustment is finished.

先导压力调整螺钉 Pilot pressure adjust bolt

(2)、拧下压力表和测压接头，用16Nm的扭矩拧紧螺塞。 Remove pressure gauge and pressure testing joint. Tighten the plug to a torque of 16Nm.

5.4 先导压力调整 Pilot pressure adjust 先导溢流阀 Pilot relief valve

适用机型 Model： 922D(Ⅲ)

如果先导压力值不正确，请按以下步骤进行调整： If the Pilot pressure pressure value is incorrect, adjust it as following procedure: (1)、松开先导溢流阀上的锁紧螺母，用内六角扳手拧紧先 导溢流阀上的螺钉，顺时针方向压力升高，逆时针方向压力 降低,当压力值达到3.9~4.1MPa时，上紧锁紧螺母，压力调 整完成； Loose locknut that installed on the pilot relief valve as shown in the illustration. The pressure will increase when rotate in clockwise direction and decrease when rotate in anticlockwise direction. Tighten locknut 312 when the pressure value reaches to 3.9~4.1MPa. After that, pressure adjustment is finished. (2)、拧下压力表和测压接头，用16Nm的扭矩拧紧螺塞。 Remove pressure gauge and pressure testing joint. Tighten the plug to a torque of 16Nm.

目录 Table of contents 1.液压基础知识 Hydraulic basic knowledge z 2.液压元件介绍 The introduction of hydraulic components z 3.挖掘机液压系统 Hydraulic system of excavator z 4.液压管路介绍 The introduction of hydraulic pipe line z 5. 压力测试与调整 Pressure test and adjust z 6. 故障分析与处理 Troubleshooting z

6.1 液压元件动作缓慢 Hydraulic components works slowly 原因 Cause

解决办法 Solutions

1

低油位 Low oil level

给液压箱加油至充满记号 Add oil to oil tank to the full mark

2

冷油 Cold oil

开动发动机给液压系统加热 Run the engine to preheat hydraulic system

3

错误的液压油 Wrong hydraulic oil

使用正确的液压油 Use the correct oil

4

发动机速度太慢 Slow engine speed

解决发动机速度慢的问题 Solve the problem of low engine speed

5

先导回路问题 Pilot oil loops

检查先导回路 Check the pilot circuit

6

泵磨损 Worn pump

更换或修理损坏的零部件 Replace or repair worn parts

7

泵吸油管受限制 Restricted pump suction pipe

检查泵的吸油管路 Check pump suction pipe

6.2 液压油过热 Hydraulic oil over hot 原因 Cause

解决办法 Solutions

1

错误的液压油 Wrong hydraulic oil

使用正确的液压油 Use the correct oil

2

低油位 Low oil level

给液压箱加油至充满记号 Add oil to oil tank to the full mark

3

泵磨损 Worn pump

更换或修理损坏的零部件 Replace or repair worn parts

4

堵塞的散热器或油冷却器 Clogged radiator or oil cooler

清扫或整顿散热器翅片 Clean or rearrange the radiator fins

5

油冷却器旁路 Oil cooler bypasses

检查回油单向阀 Check one-way valve of the oil return

6

溢流阀 Relief valve

检查或调整溢流阀 Check and adjust the relief valve

7

不清洁的液压油 Unclean oil

排油之后重新加油 Add oil after draining oil

8

不适当的调整液压组件 Improper adjustment for the hydraulic components

正确的调整液压组件 Proper adjustment for the hydraulic components

6.3 低压或无油压 Low pressure or no oil pres-sure 原因 Cause

解决办法 Solutions

1

错误的液压油 Wrong oil

使用正确的液压油 Use the correct oil

2

不适当的调整液压组件 Improper adjustment for the hydraulic components

正确的调整液压组件 Proper adjustment for the hydraulic components

3

系统内无液压油 No oil in the hydraulic system

加进正确的液压油 Add the correct oil

4

磨损的液压缸 Worn cylinder

更换或修理损坏的零部件 Replace or repair worn parts

5

溢流阀 Relief valve

检查或调整溢流阀 Check and adjust the relief valve

6.4 液压缸工作但不能提升载荷 Cylinder can work but can not lift load 原因 Cause

解决办法 Solutions

1

泵磨损 Worn pump

更换或修理损坏的零部件 Replace or repair worn parts

2

主溢流阀压力低 Low pressure of main relief valve

检查和调整主溢流阀压力Check and adjust the main relief valve pressure

3

液压油位低 Low oil level

加液压油 Add oil

4

吸油滤网堵塞 Clogged the filter

清扫滤网和系统 Clean the filter and the system

5

泵吸油管渗漏 Pump suction pipeline leaks

检查吸油管 Check suction pipeline

6.5 一个控制操作杆不工作 One control lever does not work 原因 Cause

解决办法 Solutions

1

油口溢流阀压力过低 Low pressure of the oil port relief valve

检查和调整油口溢流阀压力Check and adjust the oil port relief valve pressure

2

钢管或软管损坏 Tube or hose damaged

修理或更换 Repair or replace

3

液压装置松弛 Hydraulic components loosen

拧紧 Tighten

4

在装配中损坏O形圈 更换新O形圈 O-ring is damaged when assembled Replace a new O-ring

5

先导阀 Pilot valve

修理或更换先导阀上损坏的零部件 Repair or replace worn parts of pilot valve

6

先导管路 Pilot lines

修理或更换 Repair or replace

6.6 一个液压缸不工作 One cylinder does not work 原因 Cause

解决办法 Solutions

1

控制阀阀芯损坏或被灰尘污染 Spool of control valve damaged or polluted by dust

更换和修理主控阀损坏部件或清洗它 Replace and repair worn parts of control valve or cleaning it

2

钢管或软管损坏 Tube or hose damaged

修理或更换 Repair or replace

3

液压装置松弛 Hydraulic components loosen

拧紧 Tighten

4

液压元件中的O形圈损坏 更换新的O形圈 O-ring of hydraulic components damaged Replace a new O-ring

5

先导阀 Pilot valve

6

先导管路 Pilot pipeline failure

修理或更换先导阀上损坏的零部件 Replace and repair worn parts of hand pilot valve or clean it 修理或更换 Repair or replace

6.7 一个行走马达不工作 One travel motor does not work 原因 Cause

解决办法 Solutions 修理或更换行走马达上损坏的零部件

1

行走马达 Travel motor trouble

2

中心接头故障 Center swivel joint trouble

检查中心接头是否内漏 Check for internal leakage of center swivel joint

3

没释放驻刹车器 Do not set free brake pedal

更换或修理驻刹车器 Replace and repair brake

4

行走先导阀 Travel pilot valve

5

先导管路 Pilot circuit

Replace and repair worn parts of travel motor or clean it

修理或更换行走先导阀上损坏的零部件

Repair or replace worn parts of travel pilot valve or clean it 修理或更换 Repair or replace

6.8 不能回转 Can not swing

原因 Cause

解决办法 Solutions

1

回转制动器释放阀 Swing brake release valve

更换或修理回转制动器释放阀 Replace and repair swing brake release valve

2

回转马达 Swing motor

更换或修理回转马达上损坏的零部件 Replace and repair worn parts of swing motor

3

先导阀 Pilot valve

修理或更换先导阀上损坏的零部件 Replace and repair worn parts of hand pilot valve or clean it

谢谢！ Thank you ! 问题？ Questions?