Gradall 544D (9136-4003) Service Manual User Manual download pdf (Page 62)

Gresen’s Model V40 Directional Control Valves are

available with five different types of work sections, plus

various options to meet specific job specifications.

The following paragraphs describe the five work

sections and options with reference to the parts illus-

trations in Section IV in this manual.

3-WAY, 3-POSITION PARALLEL WORK SECTION

(Refer to Figure 4-2)

Provides control of single acting cylinders or start and

stop of non-reversible hydraulic motors where free-

wheeling of motor is NOT required. The work port is

blocked in neutral position.

4-WAY, 3-POSITION PARALLEL WORK SECTION

(Refer to Figure 4-3)

Provides control of double acting cylinders without the

floating action plus hydraulic motor start, stop,

reverse control where free-wheeling is NOT required.

Work ports are blocked in neutral position.

4-WAY, 3-POSITION TANDEM (PRIORITY) WORK

SECTION (Refer to Figure 4-3).

When combining parallel and tandem work sections in

the same V40 valve assembly, the tandem section and

all sections upstream from the tandem section have

priority. If the spool in the tandem section is fully actu-

ated, no oil is available to downstream work sections.

4-WAY, 4-POSITION FLOAT WORK SECTION (Refer

to Figure 4-4)

Provides control of double-acting cylinders requiring a

floating action such as: loaders, dozers, snow plows,

etc. Incorporated into the work section is a 4-position

float positioner. Three positions are standard double-

acting with spring return to neutral. The fourth position is

detented to hold in float position (both work ports open

to tank).

4-WAY, 4-POSITION REGENERATIVE WORK

SECTION (Refer to Figure 4-5).

Same as 4-way, 3-position work section except that

the fourth “regeneration” position provides a large vol-

ume of oil for fast cylinder action, but with little force.

MID-INLET SECTION (Refer to Figures 4-6 & 4-7).

Provides an inlet port for a secondary pump down-

stream in the valve assembly. Mid-inlet sections are

available in split flow, combined flow, and a two-position

SECTION II

DESCRIPTION

section for two-speed split or combined low application.

SPOOL ACTION OPTIONS

SPRING RETURN TO NEUTRAL (Standard) (Refer to

Figure 4-10).

Spool will return to neutral position from “A” or “B” power

position when handle is released.

SPRING EXTENDED SPOOL, “A” Option (Refer to

Figure 4-12).

Eliminates spring return to neutral. Spring returns to

the spool “OUT” position only. Usually used for cam

operation of spool.

3-POSITION DETENT, “D” Option (Refer toFigure

4-13).

Valve spool remains in any of three detented positions.

No spring return to neutral.

DETENT WITH SPRING RETURN TO NEUTRAL,

“R” Option (Refer to 4-14).

Can be used on either 3-way or 4-way free flow spool.

Has detent position for either spool “in”, spool “out”, or

2-position detent for both spool “in” and spool “out”

positions, with spring return to neutral position.

SPOOL TRAVEL LIMITER POSITIONER, “L” Option

(Refer to 4-15).

Allows the forward spool travel (spool “in” to be adjusted

to a very fine degree, allowing a restricted amount of

pressurized oil to pass through “A” port of the control

valve. Standard spring return to neutral assembly is

provided.

For 3-way (single-acting cylinder operation, “A” port is

plugged and “B” port only is used. Therefore, the spool

travel assembly would restrict exhausting oil from

work port “B” to tank port.

INTERNAL HYDRAULIC DETENT RELEASE, “KO”

Option (Refer to Figure 4-16).

Automatically returns spool to a neutral position as soon

as work cycle is completed.

ROTARY SPOOL ACTUATOR, “W” Option (Refer to

Figure 4-20).

Movement of spool is controlled by a rotary movement

of the handle. Allows 90° rotation of spool in each

direction from center.

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Gradall 544D (9136-4003) Service Manual User Manual Page 62

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