Created on:2021-09-13 10:42

Construction machinery_ Maintenance of excavator_ Example of detection method for proportional valve of main pump

Construction machinery_ Maintenance of excavator_ Example of detection method for proportional valve of main pump

① The test of proportional valve of Liebherr excavator takes the commissioning of main pump of r984 excavator as an example. See the following table for the standard values of detection parameters of proportional valve.

 

Test results of proportional valve of Liebherr excavator

 

Engine speed / (R / min)

输入电流/mA

二次油压/kPa

主泵P1(BP260)

1800

345+10

1000±100

主泵P2(BP260)

1650

<210

<400

主泵P3(BP260)

1800

600+15

1600±100

1650

<300

<700

 

② The test of proportional valve of caterpillar excavator takes cat320b excavator as an example. During the scanning test of EPR proportional valve, the password must be input through the monitoring board to enter the maintenance mode, the throttle knob is located at "10", and the operating handle is fully set to the middle position; Connect a pressure gauge with a measuring range of 6Mpa at the output end of EPR proportional valve (secondary oil pressure Ps measuring point), and put the clamp ammeter into the EPR valve wire; The engine is off, but the start switch is on. In the 20s scanning cycle, when the current increases from 200mA to 1750ma, if the secondary oil pressure increases from 490kpa to 3450kpa, the EPR valve is normal.

③ The test of proportional valve of Shengang excavator takes the proportional valve for main pump of Sk-6 series excavator as an example. The coil resistance value on it should be (17.5 ± 1) Ω. The standard values of input current and secondary oil pressure detection parameters are shown in the table below.

 

Test results of proportional valve of Shengang excavator

测试条件

SK200-6

Sk230-6

SK320-6

输入电流

/mA

二次油压

//kPa

输入电流

/mA

二次油压

//kPa

输入电流

/mA

二次油压

/kPa

操纵杆中立,发动机中速转动

700±70

2646±260

720±72

2744±270

700±70

2646±260

操纵杆中立,发动机高速转动

750±75

2940±290

770±77

3088±300

770±77

3136±310

发动机高速转动,测P1泵(右侧履带空转),测P2泵(左侧履带空转)

350±35

588±60

350±35

588±60

350±35

588±60

 

④ The test of the proportional valve of Komatsu excavator takes Komatsu pc200-6 and PC220-6 excavators as examples. If the resistance of the coil is 7 ~ 14 Ω and the resistance between the ground wire and the machine body is more than 1m Ω, it is normal. The start switch is powered on, the engine is placed at the maximum throttle position, and the operating handle is neutral. If the input current is (320 ± 80) MA, it is normal.

⑤ The test of the proportional valve of Daewoo excavator takes Daewoo dh220ijc - Ⅲ excavator as an example. The standard values of the detection parameters of the proportional valve are shown in the table below.

 

Test results of proportional valve of Daewoo excavator

动力模式

作业模式

输入电流/mA

一次油压/kPa

H(I速)

挖掘

400±40

147±15

装车

600±60

284±28

S(II速)

平整

0

0

 

⑥ Test of proportional valve of modern excavator take modern r290-3 excavator as an example. During eppr valve test, after starting the engine, operate the bucket control handle under the specified power mode and engine speed. The standard values of input current and corresponding secondary oil pressure detection parameters of bucket circuit in overflow position are shown in the table below.

 

Test results of proportional valve of modern excavator

动力模式

发动机转速/(r/min)

输入电流/mA

二次油压/kPa

H

2050±50

240±24

392±39

S

2050±50

290±29

784±78

L

1850±50

450±45

1960±19

F

1550±50

600±60

3234±32

 

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