re29178 - Bosch Rexroth

Proportional pressure
reducing valve, pilot operated
Types DRE(M) and DRE(M)E
Size 32 1)
Component series 4X
Maximum operating pressure 315 bar
Maximum flow 300 L/min
Table of contents
Contents Page
Features 1
Ordering code, preferred types 2
Symbols 2
Function, section 3, 4
Technical data 4, 5
Electrical connection, cable sockets 6
Control electronics 5, 7
Characteristic curves 8, 9
Unit dimensions 10
1) For sizes 10 and 25, see data sheet RE 29176
Information about available spare parts:
www.boschrexroth.com/spc
Features
RE 29178/04.05
Replaces: 11.02
H20448
– Valve for reducing an operating pressure
– Operation by proportional solenoid
– For subplate mounting:
Position of ports according to DIN 24340 form D,
subplates to data sheet RE 45062
(separate order), see page 10
– Optional check valve between A and B
– Optional maximum pressure relief function
– Valve and control electronics from a single source
– For controlling types DRE and DREM:
1/10
• Analogue amplifier type VT-VSPA1(K)-1 in Euro-card format
(separate order), see page 5
• Digital amplifier type VT-VSPD-1 in Euro-card format
(separate order), see page 5
• Analogue amplifier type VT 11030 of modular design
(separate order), see page 5
– Types DREE and DREME with integrated electronics (OBE):
• Low manufacturing tolerances of the command value/
pressure characteristic curve
• Ramp times can be set independently for pressure build-up
and pressure reduction

2/10 Bosch Rexroth AG Hydraulics DRE(M); DRE(M)E RE 29178/04.05
Ordering code
Without maximum pressure
relief function = No code
With maximum pressure
relief function = M
For external control electronics = No code
With integrated electronics (OBE) = E
Size 32 = 30
Component series 40 to 49 = 4X
(40 to 49: unchanged installation and connection dimensions)
Pressure stage
50 bar = 50
100 bar = 100
200 bar = 200
315 bar = 315
Pilot oil drain always external,
separate, and at zero pressure to tank
= Y
With check valve between A and B = No code
Without check valve = M
Preferred types
Type Material no.
DREE 30-4X/50YMG24K31M R900954516
DREE 30 -4X/100YMG24K31M R900954513
DREE 30-4X/200YMG24K31M R900954514
DREE 30-4X/315YMG24K31M R900954515
Symbols
A Y
B
A Y
B
DRE 30 4X Y G24 *
A Y
B
A Y
B
A Y
B
A Y
B
Further details in
clear text
Seal material
M = NBR seals,
suitable for mineral oil (HL, HLP)
to DIN 51524
V = FKM seals
suitable for phosphate ester
(HFD-R)
Electrical connection
for DRE; DREM:
K4 = Without cable socket, with component
plug to DIN EN 175301-803
Cable socket – separate order
see page 6
For DREE; DREME
K31 = Without cable socket, with
component plug to DIN EN 175201-804
Cable socket – separate order
see page 6
Supply voltage of
control electronics
G24 = 24 V DC
DRE 30-4X/...YM… DREM 30-4X/...YM… DRE 30-4X/...Y… DREM 30-4X/...Y…
A Y
DREE 30-4X/...YM… DREME 30-4X/...YM… DREE 30-4X/...Y… DREME 30-4X/...Y…
B
A Y
B

RE 29178/04.05 DRE(M); DRE(M)E Hydraulics Bosch Rexroth AG 3/10
Function, section
Valves of types DRE and DREM are pilot operated pressure
reducing valves. They are used for reducing an operating pressure.
These valves basically consist of a pilot control valve (1) with
proportional solenoid (2), a main valve (3) with main spool insert
(4) and optionally a check valve (5).
Type DRE...
The pressure in channel A is adjusted by a proportional solenoid
(2) in relation to a current.
At the rest position – no pressure in channel B – the spring
(11) holds the main spool (4) in the initial position. The connection
from channel B to A is open.
The pressure in channel A acts on the bottom side of the main
spool in the direction of closing, and the pressure of the pilot
control valve on the spring side of the main spool in the direction
of opening from channel B to A.
The pilot oil is taken from channel B and flows through the bore
(6) to the constant-flow control valve (9) that keeps the pilot
oil flow constant independently of the pressure drop between
channel A and B. The pilot oil flows from the constant-flow control
valve (9) through bores (7) via the valve seat (10), passes
the valve poppet (8) and is directed into the Y channel to the
tank.
The pressure desired in channel A is pre-selected on the associated
amplifier. The proportional solenoid pushes the valve
9
6
11
12
7 1 10 8 2
X X
13
A B Y
Type DRE. 30-4X/.Y.G24K4… (with check valve)
3
4
5
poppet (8) against the valve seat (10) and limits the pressure in
the spring chamber (12) to the set value. At the control position
of the main spool (4), the hydraulic fluid flows from channel B
to A and generates pressure in channel A (setting of the pilot
control valve plus spring (11)).
When the set pressure is reached in A, a balance of forces is
achieved on the main spool.
When the actuator connected to port A is not moving (e.g.
cylinder piston at end position), and a lower pressure is set in
channel A via the proportional solenoid (2), the main spool (4)
closes the connection from B to A and at the same time opens
the connection from channel A to the spring chamber (12) of
the main spool (4). At this position, the compressed volume in
channel A can expand via the pilot control valve (1) and port Y.
A check valve (5) can optionally be installed to allow a free return
flow from channel A to B.
The reduced pressure in channel A can be checked by means
of a pressure gauge port (13).
Type DREM...
For the hydraulic protection against impermissibly high electrical
control currents on the proportional solenoid, which inevitably
result in high pressures in port A, a spring-loaded pressure
relief valve can optionally be installed as maximum pressure relief
feature (14).
14
X-X
A B
5

4/10 Bosch Rexroth AG Hydraulics DRE(M); DRE(M)E RE 29178/04.05
Function, section
Types DREE and DREME – with integrated electronics (OBE)
In terms of function and design, these valves correspond to
types DRE and DREM, except for the integrated electronics.
The electronics accommodated in a housing (15) receives the
supply voltage and command value voltage via the cable socket
(16).
The command value/pressure characteristic curve (zero point
on valve seat (10) and gradient on Imax po ten tio me ter (R30) in
the electronics) is adjusted in the factory with narrow manufacturing
tolerances.
The ramp time for pressure build-up and pressure reduction
can be adjusted independently of each other using two potentiometers.
For further information on the integrated electronics, see page 7.
Technical data (for applications outside these parameters, please consult us!)
General data
Weight – DRE and DREM kg 8.6
– DREE and DREME kg 8.7
Installation orientation Optional
Storage temperature range °C – 20 to + 80
Ambient – DRE and DREM °C – 20 to + 70
temperature range – DREE and DREME °C – 20 to + 50
Hydraulic (measured with HLP 46; ϑoil = 40 °C ± 5 °C )
Max. operating pressure – Ports A and B bar 315
– Port Y Separately and at zero pressure to tank
Max. set pressure – Pressure stage 50 bar bar 50
in channel A – Pressure stage 100 bar bar 100
– Pressure stage 200 bar bar 200
– Pressure stage 315 bar bar 315
Min. set pressure in channel A with zero command value bar See p min -q v characteristic curve on page 9
Maximum pressure relief function (infinitely adjustable): Adjustment range: Factory setting:
– Pressure stage 50 bar bar 30 to 70 to 70 bar
– Pressure stage 100 bar bar 50 to 130 to 130 bar
– Pressure stage 200 bar bar 90 to 230 to 230 bar
– Pressure stage 315 bar bar 150 to 350 to 350 bar
Max. flow of main valve L/min 300
Pilot oil flow L/min See characteristic curve on page 9
16
15

RE 29178/04.05 DRE(M); DRE(M)E Hydraulics Bosch Rexroth AG 5/10
Technical data (for applications outside these parameters, please consult us!)
Hydraulic (measured with HLP 46; ϑ oil = 40 °C ± 5 °C )
Hydraulic fluid Mineral oil (HL, HLP) to DIN 51524,
phosphate ester (HFD-R)
Hydraulic fluid temperature range °C – 20 to + 70
Viscosity range mm 2 /s 15 to 380
Max. permissible degree of contamination of the hydraulic
fluid - cleanliness class to ISO 4406 (c)
Class 20/18/15 1)
Hysteresis % ± 2.5 of max. set pressure
Repeatability % < ± 2 of max. set pressure
Linearity % ± 3.5 of max. set pressure
Manufacturing tolerances – DRE and DREM % ± 2 of max. set pressure
of comand value/pressure – DREE and DREME % ± 1.5 of max. set pressure
curve referred to hysteresis curve, increasing pressure
Switching time
Electrical
ms 100 to 300 (depending on system)
Supply voltage V 24 DC
Min. solenoid current – DRE and DREM mA 100
– DREE and DREME mA 100
Max. solenoid current – DRE and DREM mA 800 (corresponds to 100 % command value)
– DREE and DREME mA 1440 to 1760
Solenoid coil resistance – Cold value at 20 °C Ω 19.5 with DRE / DREM; 5.4 Ω with DREE / DREME
– Max. hot value Ω 28.8 with DRE / DREM; 7.8 Ω with DREE / DREME
Duty cycle % 100
Electrical connection – DRE and DREM With component plug to DIN EN 175301-803
Cable socket to DIN EN 175301-803 2)
– DREE and DREME With component plug to DIN EN 175201-804
Cable socket to DIN EN 175201-804 2)
Type of protection of valve to EN 60529 IP 65 with cable socket mounted and locked 3)
Control electronics
– For DREE and DREME
– For DRE and DREM
Integrated in the valve, see page 7
• Amplifier in Euro-card format analogue VT-VSPA1(K)-1 to data sheet RE 30111
(separate order) digital VT-VSPD-1 to data sheet RE 30123
• Amplifier of modular design (separate order) analogue VT 11030 to data sheet RE 29741
1) The cleanliness classes specified for components must be
adhered to in hydraulic systems. Effective filtration prevents
malfunction and, at the same time, prolongs the service life
of components.
For the selection of filters, see data sheets RE 50070,
RE 50076, RE 50081, RE 50086 and RE 50088.
2) Separate order, see page 6
3) Special types of protection on enquiry
Note: For details regarding environment simulation
testing in the fields of EMC (electromagnetic
compatibility), climate and mechanical stress,
see RE 29176-U (declaration on environmental
compatibility).

6/10 Bosch Rexroth AG Hydraulics DRE(M); DRE(M)E RE 29178/04.05
Electrical connection, cable sockets (nominal dimensions in mm)
Connection to component plug Connection to cable socket
18
1
Ø27
91
10A
250V
PE
1 2
For types DRE, DREM – for external control electronics
Cable socket to DIN EN 175301-803
Separate order under material no. R901017011
27,5
2
1
GDM
43
1 Fixing screw M3,
titghtening torque M T = 0.5 Nm
~10
Ø6,5…Ø11
34,2
5,5
For types DREE, DREME – with integrated electronics (OBE)
Cable socket to DIN EN 175201-804
Separate order under material no. R900021267
(made of plastic)
For the pin assignment, see block circuit diagram on page 7.
B
C
D
A F
E
PE
1 2
to amplifier

RE 29178/04.05 DRE(M); DRE(M)E Hydraulics Bosch Rexroth AG 7/10
Integrated electronics (OBE) for types DREE, DREME
Function
The integrated electronics is controlled via both differential amplifier
connections D and E.
The ramp generator generates from a command value stepchange
(0 to 10 V or 10 to 0 V) a delayed rise or drop of the
solenoid current. The rise time can be adjusted by means of
potentiometer R14, the drop time of the solenoid current using
potentiometer R13.
The maximum ramp time of 5 s is only possible over the full
command value range. With minor command value changes,
the ramp time shortens.
The command value/solenoid current characteristic curve is adjusted
to the valve by means of the characteristic curve generator
so that non-linearities in the hydraulic system are compensated
for and a linear command value/pressure characteristic
curve is obtained.
Block circuit diagram / pin assignment of integrated electronics
Command value 0 to 10 V
0V reference potential
Supply voltage:
U eff : 22 to 33 V
Supply voltage
0 V
D
+
E
–
F
C
A
+
B
n.c.
n.c.
Dif fe rential
amplifier
U
=
U
=
Ramp
generator
R 14 R 13
Ram p
“up“
Power supply unit
+U
+7,5 V
-7,5 V
Power supply unit with rectifier
Single-phase rectification or three-phase bridge :
Ueff = 22 to 33 V
Residual ripple content on the power supply unit: < 5 %
Output current: Ieff = max. 1.4 A
Supply cable: – Recommendation: 5-wire 0.75 or 1 mm2 with protective conductor and shield
– Outer diameter 6.5 to 11 mm
– Shield to 0 V supply voltage
Ram p
“down“
– Max. permissible length 100 m
The minimum supply voltage of the power supply unit depends
on the length of the supply cable (see diagram).
In the case of lengths > 50 m, a capacitor of 2200 µF must be
provided near the valve in the supply cable.
The current regulator regulates the solenoid current independently
of the solenoid coil resistance.
Potentiometer R30 can be used for changing the gradient of
the command value/current characteristic curve and hence the
gradient of the command value/pressure characteristic curve of
the proportional pressure control valve.
Potentiometer R43 is used for adjusting the biasing current. Its
setting should not be changed. If required, the zero point of the
command value/pressure characteristic curve can be adjusted
on the valve seat.
The power stage of the electronics for controlling the proportional
solenoid is a chopper amplifier. It is pulse-width-modulated
and has a clock frequency of 300 Hz.
The solenoid current can be measured at the two measuring
sockets MP1 and MP2. A voltage drop of 0.352 V at the measuring
shunt corresponds to a solenoid current of 1.6 A.
Char. curve
generator
Internal reference point
Min. supply voltage in V →
R 30 I R 43
30
28
26
24
22
Current
regulator
I max
300 Hz
=
I min
Oscillator
+U
Chopper
amplifier
Measuring shunt
R = 0.22 Ω
0 V
20 40 60 80 100
Length of supply cable in m →
Solenoid
MP1
1,6 A =
0,352 V
MP2
0,75 mm 2
1 mm 2

8/10 Bosch Rexroth AG Hydraulics DRE(M); DRE(M)E RE 29178/04.05
Characteristic curves (measured with HLP46, ϑ oil = 40 °C ± 5 °C)
Pressure in channel A in dependence on command value (measured at flow of 0 L/min from B to A and with associated control
electronics)
Pressure in channel A in bar →
Pressure in channel A in bar →
Pressure stage 50 bar Pressure stage 100 bar
50
100
90
40
30
20
Dead range
10
0
160
140
120
100
80
60
40
20
0
25 50 75
Command value in % →
25 50 75
Command value in % →
100
100
80
70
60
50
40
30
20
10
0
25 50 75
Command value in % →
Pressure stage 200 bar Pressure stage 315 bar
200
315
300
180
300
250
200
150
100
50
Dead range
0 0,1 1 5 10 50 100 200 300
Flow in L/min →
Druck im Kanal A in bar →
250
200
150
100
Dead range
50
0
100
80
60
40
20
0
Dead range
25 50 75
Command value in % →
Note: In order that the lowest settable pressure is achieved, the biasing current must not exceed max. 100 mA.
Pressure in channel A in dependence on flow q v
Pressure in channel A in bar →
Pressure in channel A in bar →
100
100
Pressure in channel A in dependence on pressure in channel B
Pressure in channel A in bar →
50 100 150 200 250 300
Pressure in channel B in bar →

RE 29178/04.05 DRE(M); DRE(M)E Hydraulics Bosch Rexroth AG 9/10
Charcteristic curves (measured with HLP46, ϑ oil = 40 °C ± 5 °C)
Min. set pressure in bar →
12
10
8
6
4
2
0
10
8
6
4
2
0
p min -q v characteristic curve
50 100 150 200 250 300
Flow in L/min →
Pressure differential from A to B across check valve Pilot oil flow
Pressure differential in bar →
50 100 150 200 250 300
Flow in L/min →
Pilot oil flow in L/min →
3,0
2,0
1,4
1,0
0
50 100 150 200 250 300
Flow in L/min →

10/10 Bosch Rexroth AG Hydraulics DRE(M); DRE(M)E RE 29178/04.05
Unit dimensions (nominal dimensions in mm)
170
154,5
16
11 9
120
96,8
3 1 14 12
3
16,7
Y
24,6
42,1
A B
113
Ø 6
7; 10
A B
Y
6
Ø 18
Ø 11
3,8
46
5
206 15
Pg1
45
92,8
8 59,5
6
Bosch Rexroth AG
Hydraulics
Zum Eisengießer 1
97816 Lohr am Main, Germany
Phone +49 (0) 93 52 / 18-0
Fax +49 (0) 93 52 / 18-23 58
documentation@boschrexroth.de
www.boschrexroth.de
Y
62,7
67,5
28 84,2
140
176,5
244,5 (with integrated electronics)
2
13
4
5
1 This port (G1/4) is plugged when the valve
leaves the factory. After the plug was removed,
the port can be used for separate
external pilot oil draining to tank at zero
pressure.
2 Space required to remove cable socket
3 Nameplate
4 Maximum pressure relief valve type
DREM…
When using these valves, observe the technical
data on page 4!
5 Check valve, optional
6 Locating pin
7 Pilot oil drain always external and separately
at zero pressure to tank
8 Blind counterbore
9 Identical seal rings for ports A and B
10 Identical seal rings for port Y and blind
counterbore (item 8)
11 Pressure gauge port G 1/4; 12 deep
12 Cable socket for type DRE(M)
(separate order, see page 6)
13 Cable socket for type DRE(M)E
(separate order, see page 6)
14 Integrated electronics (OBE), type
DRE(M)E with component plug “K31“
Subplates according to data sheet
RE 45062 and valve fixing screws must be ordered
separately.
Subplates: G 414/01 (G 1 1/4)
G 415/01 (G 1 1/2)
Valve fixing screws:
6 off M10 x 70 DIN 912-10.9,
Tightening torque MT = 75 Nm
Tolerances according to:
– General tolerances ISO 2768-mK
– Tolerancing principle ISO 8015
0,01/100mm
Rzmax 4
Required surface finish
of the mating part
© This document, as well as the data, specifi cations and other
information set forth in it, are the exclusive property of Bosch Rexroth
AG. Without their consent it may not be reproduced or given to third
parties.
The data specifi ed above only serve to describe the product. No
statements concerning a certain condition or suitability for a certain
application can be derived from our information. The given information
does not release the user from the obligation of own judgement and
verifi cation. It must be remembered that our products are subject to a
natural process of wear and aging.

RE 29178/04.05 DRE(M); DRE(M)E Hydraulics Bosch Rexroth AG 11/10
Notes
Bosch Rexroth AG
Hydraulics
Zum Eisengießer 1
97816 Lohr am Main, Germany
Phone +49 (0) 93 52 / 18-0
Fax +49 (0) 93 52 / 18-23 58
documentation@boschrexroth.de
www.boschrexroth.de
© This document, as well as the data, specifi cations and other
information set forth in it, are the exclusive property of Bosch Rexroth
AG. Without their consent it may not be reproduced or given to third
parties.
The data specifi ed above only serve to describe the product. No
statements concerning a certain condition or suitability for a certain
application can be derived from our information. The given information
does not release the user from the obligation of own judgement and
verifi cation. It must be remembered that our products are subject to a
natural process of wear and aging.

12/10 Bosch Rexroth AG Hydraulics DRE(M); DRE(M)E RE 29178/04.05
Notes
Bosch Rexroth AG
Hydraulics
Zum Eisengießer 1
97816 Lohr am Main, Germany
Phone +49 (0) 93 52 / 18-0
Fax +49 (0) 93 52 / 18-23 58
documentation@boschrexroth.de
www.boschrexroth.de
© This document, as well as the data, specifi cations and other
information set forth in it, are the exclusive property of Bosch Rexroth
AG. Without their consent it may not be reproduced or given to third
parties.
The data specifi ed above only serve to describe the product. No
statements concerning a certain condition or suitability for a certain
application can be derived from our information. The given information
does not release the user from the obligation of own judgement and
verifi cation. It must be remembered that our products are subject to a
natural process of wear and aging.