23-Row Wing Fold Hydraulic System

N88535-UN-20MAY10

A - Outer Wing Fold Valve

B - Center Flow Divider Manifold

The following schematics illustrate the six system states of the outer wing fold valve (A) during unfolding and folding. The 23-row wing fold hydraulic system uses two outer wing fold valves, one on each outer wing. The following schematics only show the outer wing fold valve and not the center flow divider manifold (B).

N88528-UN-25MAY10

Wing Fold Hydraulic System Components

Legend	Component	Description
A	SV1 Valve Cartridge	Normally OPEN valve. Should receive 12V once switch closes.
B	SV2 Valve Cartridge	Normally CLOSED valve. Should receive 12V once switch closes.
C	Counter Balance Valve Cartridge (CB1)	Three circuits through the valve 1. Opens via pilot pressure at point 6—allows oil to flow out port R. 2. Opens via pressure greater than 17 237 kPa (172 bar) (2500 psi) from port R at point 7. 3. Directional flow check valve always allows oil to flow from port T towards port R from point 8 to point 7.
D	PSI Valve Cartridge	Pressure activated valve. Normally closed. Opens when pressure at point 1 reaches 15 168 kPa (151.6 bar) (2200 psi).
E	Port P (Pressure from Tractor)	To main frame splitter valve, pressure side.
F	Port H	To base end of outer wing fold cylinder.
G	Port R	To rod end of outer wing fold cylinder.
H	Port 2	To rod end of front fold wing cylinder.
I	Port T (Return to Tractor)	Return to tractor via junction with other machine return lines.
J	Oil to base end of front fold wing cylinder	Teed external of valve at port P.
K	Outer Wing Fold Valve	One valve per front fold wing.
L	Cylinder	Front Fold Wing
M	Cylinder	Outer Wing Fold

1. NOTE: With all unfolding procedures, the inner wing will be fully unfolded first.

   Unfolding, Switch OFF

   
   N88529-UN-25MAY10

   Component Status

   Legend

   A

   B

   C

   D

   E

   F

   G

   H

   I

   J

   K

   L

   M

   System State

   SV1 normally open

   SV2 normally closed

   CB1

   PS1

   Port P (Pressure from Tractor)

   Port H

   Port R

   Port 2

   Port T (Return to Tractor)

   Base End Front Folding Wing Cylinder

   Outer Wing Fold Valve

   Front Fold Wing Cylinder

   Outer Wing Fold Cylinder

   Machine Movement

   Unfolding, switch off

   Open

   Closed

   Open via pilot pressure at point 6, allowing oil flow from point 7 to 8

   Closed, no flow through

   Pressure oil from main frame splitter

   Oil flow from port P, through SV1, to base end of outer wing fold cylinder

   Oil from rod end outer wing fold cylinder

   No flow, SV2 closed

   Oil from port R through CB1

   No flow, no path from rod end

   Outer wing unfolding and front fold wing stationary

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2. Unfolding, Switch On, Front Fold Cylinder Extending

   
   N88530-UN-25MAY10

   Component Status

   Legend

   A

   B

   C

   D

   E

   F

   G

   H

   I

   J

   K

   L

   M

   System State

   SV1 normally open

   SV2 normally closed

   CB1

   PS1

   Port P (Pressure from Tractor)

   Port H

   Port R

   Port 2

   Port T (Return to Tractor)

   Base End Front Folding Wing Cylinder

   Outer Wing Fold Valve

   Front Fold Wing Cylinder

   Outer Wing Fold Cylinder

   Machine Movement

   Unfolding, switch on, front fold wing cylinder extending

   Closed

   Open

   Closed, no pressure

   Closed, no flow through

   No flow, no oil path

   No flow, no oil path

   No flow, CB1 closed

   Oil flow from rod end of front fold wing cylinder.

   Return oil from port 2 through SV2

   Pressure oil from main frame splitter

   Outer wing stops, not completely unfolded and front fold wing completely unfolds

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3. Unfolding, Switch On, Front Fold Wing Cylinder Fully Extended

   
   N88531-UN-25MAY10

   Component Status

   Legend

   A

   B

   C

   D

   E

   F

   G

   H

   I

   J

   K

   L

   M

   System State

   SV1 normally open

   SV2 normally closed

   CB1

   PS1

   Port P (Pressure from Tractor)

   Port H

   Port R

   Port 2

   Port T (Return to Tractor)

   Base End Front Folding Wing Cylinder

   Outer Wing Fold Valve

   Front Fold Wing Cylinder

   Outer Wing Fold Cylinder

   Machine Movement

   Unfolding, switch on, front fold wing cylinder fully extended

   Closed

   Open

   Open via pilot pressure from PS1

   Open, pressure exceeds 15 168 kPa (151.6 bar) (2200 psi) allowing oil flow from point 1 to 2

   pressure oil from main frame splitter to PS1

   Oil flow from port P, through PS1, to base end of outer wing fold cylinder

   Oil from rod end outer wing fold cylinder

   No flow, cylinder fully extended

   Oil from port R through CB1

   No flow, cylinder fully extended

   Outer wing completes unfolding

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4. NOTE: With all folding procedures, the inner wing will fold after front fold wing and outer wing are fully folded.

   Folding, Switch On, Front Fold Wing Cylinder Retracting

   
   N88532-UN-25MAY10

   Component Status

   Legend

   A

   B

   C

   D

   E

   F

   G

   H

   I

   J

   K

   L

   M

   System State

   SV1 normally open

   SV2 normally closed

   CB1

   PS1

   Port P (Pressure from Tractor)

   Port H

   Port R

   Port 2

   Port T (Return to Tractor)

   Base End Front Folding Wing Cylinder

   Outer Wing Fold Valve

   Front Fold Wing Cylinder

   Outer Wing Fold Cylinder

   Machine Movement

   Folding, switch on, front fold wing cylinder retracting

   Closed, no oil flow from H towards P. (See CB1 in this step.)

   Open

   No oil flow because pressure to retract wing fold cylinder and outer wing fold is greater than the pressure to retract the front fold wing cylinder.

   No flow

   Flow from base end of outer wing fold cylinder

   Flow to rod end of outer wing cylinder

   Flow to rod end of front fold wing cylinder

   Flow from tractor

   Flow from returning to main frame splitter

   Front fold wing starts and completes folding. This movement is controlled by hydraulic flow through the path of least resistance.

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5. Folding, Switch On, Front Fold Wing Cylinder Fully Retracted

   
   N88533-UN-25MAY10

   Component Status

   Legend

   A

   B

   C

   D

   E

   F

   G

   H

   I

   J

   K

   L

   M

   System State

   SV1 normally open

   SV2 normally closed

   CB1

   PS1

   Port P (Pressure from Tractor)

   Port H

   Port R

   Port 2

   Port T (Return to Tractor)

   Base End Front Folding Wing Cylinder

   Outer Wing Fold Valve

   Front Fold Wing Cylinder

   Outer Wing Fold Cylinder

   Machine Movement

   Folding, switch on, front fold wing cylinder fully retracted

   Oil flow from points 4 to 5 via flow check valve circuit

   Open

   Oil flow from port T toward R from points 8 to 7 through flow check valve circuit

   No flow

   Flow from Port H via flow check valve circuit in SV1

   Flow from base end of outer wing fold cylinder

   Flow to rod end of outer wing cylinder

   No flow, cylinder fully retracted

   Flow from tractor

   No flow, cylinder fully retracted

   Outer wing begins folding immediately after full retraction of front fold wing cylinder.

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6. Folding Switch Off, Front Fold Wing Cylinder Fully Retracted

   
   N88534-UN-25MAY10

   Component Status

   Legend

   A

   B

   C

   D

   E

   F

   G

   H

   I

   J

   K

   L

   M

   System State

   SV1 normally open

   SV2 normally closed

   CB1

   PS1

   Port P (Pressure from Tractor)

   Port H

   Port R

   Port 2

   Port T (Return to Tractor)

   Base End Front Folding Wing Cylinder

   Outer Wing Fold Valve

   Front Fold Wing Cylinder

   Outer Wing Fold Cylinder

   Machine Movement

   Folding, switch off, front fold wing cylinder fully retracted

   Open

   Closed

   Oil flow from port T toward R from points 8 to 7 through flow check valve circuit

   No flow

   Flow from Port H through SV1, returns oil to tractor through center flow divider manifold

   Flow from base end of outer wing fold cylinder

   Flow to rod end of outer wing fold cylinder

   No flow, SV2 closed

   Flow from tractor return line

   No flow, no path from rod end

   Outer wing completes folding

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