Proportional pressure reducing valve, pilot-operated

Material #: R901275714

$2,945.00

Valve for reducing a system pressure Operation by means of a proportional solenoid Proportional solenoid with rotatable and detachable coil For subplate mounting: porting pattern according to ISO 5781 Third way A to Y (Ø 7.5 mm) Linearized pressure/command value characteristic curve Good transient response Optional check valve between A and B Optional maximum pressure limitation With integrated electronics (OBE)

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Valves of type DRE(M)E are pilot-operated pressure reducing valves. They are used for operating pressure reduction.

These valves basically consist of a pilot control valve (1) with proportional solenoid (2), a main valve (3) with main spool insert (4), as well as an optional check valve (5). On the proportional solenoid, there is moreover a housing (23) with the control electronics. Supply and command value voltage are applied at the connector (24). At the factory, the command value pressure characteristic curve is adjusted with little manufacturing tolerance.

 

Type DREE...

The pressure in channel A is set in a command value-dependent form via the proportional solenoid (2).

In rest position – no pressure in channel B –, the spring (17) holds the main spool (4) in its initial position. The connection from channel B to A is closed. A start-up jump is thereby prevented.

The pressure in channel A acts on the surface (7) of the main spool via the bore (6). The pilot oil is taken from channel B and flows through the bore (8) to the constant-current control (9) that keeps the pilot flow constant independent of the pressure drop between channel A and B. From

the constant-current control (9), the pilot flow flows in den spring chamber (10), through the bores (11) and (12) via the valve seat (13) into channel Y (14, 15, 16) and from there to the return flow. The pressure required in channel A is preset at the related amplifier. The proportional solenoid moves the valve poppet (20) in the direction of the valve seat (13) and limits the pressure in the spring chamber (10) to the set value. If the pressure in channel A is lower than the preset command value, the higher pressure in the spring chamber (10) moves the main spool to the right. The connection from B to A is opened. If the set pressure in A is reached, the forces at the main spool are balanced – the main spool is in control position.

Pressure in channel A • Spool face (7) = pressure in spring chamber (10) • Spool face – spring force (17)

If in a standing hydraulic fluid column (e. g. cylinder piston at stop), the pressure in A is to be reduced, (e. g.) a lower command value is preset at the control electronics and in this way a lower pressure is preselected which is present immediately in the spring chamber (10). The higher pressure in A which acts on the surface (7) of the main spool pushes the main spool to the stop against the plug screw (18). The connection A to B is blocked and A to Y is open. The force of the spring (17) now counteracts the hydraulic force acting on the surface (7) of the main spool. In this main spool position, the hydraulic fluid can flow from channel A via the control edge (19) to Y into the return flow.

When the pressure in A has dropped to the pressure in the spring chamber (10) plus ∆p from spring (17), the main spool closes the large control bores in the socket at the control edge A to Y.

The residual pressure differential of approx. 10 bar to the new command value pressure in A is now only unloaded via the fine control bore (21). In this way, a favorable transient response without pressure undershoot is achieved. For the free flow back from channel A to B, a check valve (5) can optionally be installed. Part of this flow from channel A simultaneously flows into the return flow via the open control edge (19) of the main spool A to Y.

 

Type DREME...

For hydraulic protection against an inadmissibly high electric control current at the proportional solenoid, which imperatively results in excessive pressures in port A, you can optionally install a spring-loaded pressure relief valve as maximum pressure limitation (22). The maximum pressure limitation is pre-set based on the relevant pressure rating (see table).

01

02

03

04

05

06

07

08

09

10

11

12

13

14

DRE

6X

/

Y

G24

K31

*

01

Proportional pressure reducing valve, pilot-operated

DRE

02

Without maximum pressure limitation

no code

With maximum pressure limitation

M 1)

03

With integrated electronics (OBE)

E

04

Size 10

10

Size 25

20

05

Component series 60 … 69 (60 … 69: unchanged installation and connection dimensions)

6X

Pressure rating

06

50 bar

50

100 bar

100

200 bar

200

315 bar

315

07

Pilot oil return always external, separate and depressurized to the tank

Y

08

With check valve between A and B

no code

Without check valve

M

Supply voltage of the control electronics

09

Direct voltage 24 V

G24

10

1600 mA version

no code

800 mA version

-8 2)

Electrical connection

11

Without mating connector, with connector according to DIN EN 175301-804, separate order

K31

Electrical interface

12

Command value 0 … 10 V

A1

Command value 4 to 20 mA

F1

Seal material

13

NBR seals

M

FKM seals

V

14

Further details in the plain text

*

1)

The maximum pressure limitation only serves as protection against overpressure in case of an error in the pilot valve (e. g. in case of contamination or over-current).

2)

Replacement for series 5X. (Attention! External amplifiers only suitable for G24 = 1.6 A solenoid),

For applications outside these parameters, please consult us!

general

Type

DRE(M)E

Size

10 25

Component series

6X

Installation position

Any

Weight

kg

4.8 6.1

Storage temperature range

°C

-20 … +80

Ambient temperature range

°C

-20 … +50

hydraulic

Type

DRE(M)E

Size

10 25

Maximum operating pressure

bar

315

Maximum operating pressure

Port A

bar

315

Port B

bar

315

Port T 1)

separate and depressurized to the tank

Maximum set pressure in port A

Pressure rating 50 bar

bar

50

Pressure rating 100 bar

bar

100

Pressure rating 200 bar

bar

200

Pressure rating 315 bar

bar

315

Minimum set pressure 2)

bar

2

Maximum pressure relief function

Pressure rating 50 bar 3)

bar

70

Pressure rating 100 bar

bar

130

Pressure rating 200 bar

bar

230

Pressure rating 315 bar

bar

350

Pilot flow

l/min

0.8

Maximum flow

l/min

200 300

Hydraulic fluid temperature range

°C

-20 … +80

Viscosity range

mm²/s

15 … 380

Maximum admissible degree of contamination of the hydraulic fluid, cleanliness class according to ISO 4406 (c) 4)

Class 20/18/15 according to ISO 4406 (c)

Hysteresis 5)

%

± 3.5

Repetition accuracy 5)

%

< ± 2

Linearity 5)

%

± 2

Manufacturing tolerance of the command value pressure characteristic curve 6)

%

± 1.5

Step response

10 ... 90% 7)

ms

≈ 130

90 ... 10% 7)

ms

≈ 160

10 ... 90% 8)

ms

≈ 150

90 ... 10% 8)

ms

≈ 150
1) Internal pipe Ø ≥ 5 mm; pipe length < 2500 mm
2) in channel A with command value 0
3) set at the factory
4) The cleanliness classes specified for the components must be adhered to in hydraulic systems. Effective filtration prevents faults and simultaneously increases the life cycle of the components. For the selection of the filters, see www.boschrexroth.com/filter.
5) from maximum set pressure; does not apply to types "G24-8"
6) of the maximum set pressure, related to the hysteresis characteristic curve, pressure increasing; does not apply to types “G24-8”
7) measured with standing hydraulic fluid column, 1.0 liters at port A
8) measured with standing hydraulic fluid column, 5 liters at port A

Hydraulic fluid

Classification

Suitable sealing materials

Standards

Mineral oils and related hydrocarbons

HL, HLP, HLPD, HLPP

NBR / FKM

DIN 51524

Flame-resistant   - water-free

HFDU, HFDR

FKM

ISO 12922

Flame-resistant   - containing water

HFC (Fuchs HYDROTHERM 46M, Petrofer Ultra Safe 620)

NBR

ISO12922

Important information on hydraulic fluids:

For more information and data on the use of other hydraulic fluids please contact us.

The flash point of the process and operating medium used must be 40 K over the maximum solenoid surface temperature.

Flame-resistant - containing water:
maximum pressure differential 210 bar, otherwise increased cavitation erosion!
Pressure peaks must not exceed the maximum operating pressures!
Life cycle compared to operation with HLP 30 is 30%
Maximum fluid temperature 60°C

electrical

Type

DRE(M)E

Power supply

Nominal voltage

VDC

24

Lower limit value

VDC

21

Upper limit value

VDC

35

Minimum solenoid current

with 1600 mA - coil

mA

≤ 100

with 800 mA - coil

mA

≤ 100

Maximum solenoid current

with 1600 mA - coil

mA

1760

with 800 mA - coil

mA

840

Solenoid coil resistance

Cold value at 20 °C

with 1600 mA - coil

Ω

5.5

with 800 mA - coil

Ω

20.6

Solenoid coil resistance

Maximum hot value

with 1600 mA - coil

Ω

8.05

with 800 mA - coil

Ω

33

Duty cycle

%

100

Current consumption

A

1.5

Required fuse protection

2, time-lag

Inputs

Voltage

V

0 … 10

Current

mA

4 … 20

Outlet

Actual current value

1 mV ≙ 1 mA

Protection class according to DIN EN 60529

IP65 (with mating connector mounted and locked)

(measured with HLP46, ϑOil = 40 ±5 °C)

Pressure in port A dependent on the command value (flow = 0.8 l/min)

DRE(M)E

Pressure in channel A dependent on the flow qv
(characteristic curves with constant Δp)

Size 10

Pressure in channel A dependent on the flow qv
(characteristic curves with constant Δp)

NG25

Pressure differential from A to B via the check valve

Pressure differential from B to A

Pressure in channel A dependent on the command value

Pressure rating 50 bar

Pressure rating 100 bar

Pressure rating 200 bar

Pressure rating 315 bar

Pressure rating 200 bar (with VT-SSPA1)

Comparison series 5X-6X / pressure rating 100 bar (with amplifier VT-VSPA1-1-1X with 800 mA coil)

Comparison series 5X-6X / pressure rating 315 bar (with amplifier VT-VSPA1-1-1X with 800 mA coil)

Type DREE-6X/...YM...

Type DREME-6X/...YM...

Type DREME-6X/...Y...

Type DREE-6X/...Y...

Pin assignment

Contact

Assignment interface "A1"

Assignment interface "F1"

Power supply

A

24VDC(u(t)=21...35V);Imax≤1,5A

B

0V

Reference potential actual value

C

Reference contact F; 0 V

Reference contact F; 0 V

Differential amplifier input (command value)

D

0 ... 10 V; Re = 100 kΩ

4 ... 20 mA; Re = 100 kΩ

E

Reference potential command value

Measuring output (actual value)

F

0 to 1.6 V actual value (1 mV ≙ 1 mA);
Load resistance > 10 kΩ

PE

connected to solenoid and valve housing

Connection cable

1) Connection cable:- Recommendation 6-wire, 0.75 or 1mm2 plus protective earthing conductor and screening- Connect screening to PE on supply side only- Maximum admissible length 100 m The minimum supply voltage at the power supply unit depends on the length of the supply line (see diagram)

Integrated electronics (OBE)

 

Function

The electronics are supplied with voltage via ports A and B. The command value is applied to the differential amplifier ports D and E.Via the characteristic curve generator, the command value solenoid current characteristic curve is adjusted to the valve so that non-linearities in the hydraulic system are compensated and thus, a linear command value pressure characteristic curve is created.The current controller controls the solenoid current independently of the solenoid coil resistance.The power stage of the electronics for controlling the proportional solenoid is a chopper amplifier with a clock frequency of approx. 180 Hz to 400 Hz. The output signal is pulse-width modulated (PWM). For checking the solenoid current, a voltage can be measured at the connector between pin F(+) and pin C(–) which is proportional to the solenoid current. 1 mV corresponds to 1 mA solenoid current.

Block diagram / pin assignment

Size

10 25

B1

mm

85 102

B2

mm

66.7 79.4

B3

58.8 mm 73 mm

B4

7.9 mm 6.4 mm

ØD1

mm

15 25

ØD2

H11

mm

21.8 34.8

H1

mm

192 206

H2

mm

123 137

H3

mm

58 64

H4

mm

36 44

L1

mm

42.9 60.3

L2

mm

35.8 49.2

L3

mm

31.8 44.5

L4

mm

21.5 20.6

L5

mm

7.2 11.1

L6

21.5 mm 39.7 mm

L7

5 mm 12.2 mm

L8

116 mm

L9

44.5 mm 27.3 mm

L10

59.5 mm 42 mm

T1

mm

2 2.9

1

Upon delivery, this port (G1/4) is closed. After removal of the blanking plug, an external and separate depressurized pilot oil return to the tank is, however, also possible here.

2

Space required to remove the mating connector

3

Name plate

4

Blind counterbore

5

Check valve, optional

6

Locating pin

7

Identical seal rings for ports A and B

Identical seal rings for port Y and blind counterbore (pos. 4)

8

Pilot oil return always external, separate and depressurized to the tank or optional at pos. 1

9

mating connector according to DIN EN 175301-803

10

Integrated electronics (OBE)

11

Mating connector according to DIN EN 175201-804

12

Machined valve contact surface; Porting pattern according to ISO 5781-06-07-0-00 (NG10) and ISO 5781 -08-10-0-00 (NG25)

13

Cable fastening

14

Maximum pressure limitation with version DREM and DREME

Recommended valve mounting screws (separate order):

4 hexagon socket head cap screws ISO 4762 - M10 x 45 - 10.9-flZn-240h-L

(Friction coefficient μtotal = 0.09 to 0.14)

Tightening torque MA = 59 Nm ± 10%

or

4 hexagon socket head cap screws ISO 4762 - M10 x 45 - 10.9

(Friction coefficient μtotal = 0.12 to 0.17)

Tightening torque MA = 75 Nm ± 10%

Notice:

The dimensions are nominal dimensions which are subject to tolerances.

Mating connectors for valves with round connector, 6-pole + PE

7P Z31

Mating connectors for valves with round connector, 6-pole + PE

7P Z31

For valves with round connector according to EN 175201-804, 6-pole + PE as well as 6-pole, compatible with VG 95328

Data sheet

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