re09348

Industrial Hydraulics

Electric Drives and Controls

Linear Motion and Assembly Technologies Pneumatics

Service Automation

Mobile Hydraulics

Fluid Forming – Hydroforming with Rexroth

Maximum Precision with Single-Component Forming

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Fluid Force

Forming processes,where complex sing-le-component work-pieces are pressedinto shape with thehelp of fluid pressure,have really estab- lished themselves asan efficient alterna-tive to forming under-taken by conventio-nal press tools.

Marked by a respon-sible use of resourcesin keeping with thetimes, by means ofcontinuous processdevelopment increas-ingly more is beingcreated from less ma-terial than ever before.

As worldwide innovation, techno- For high-pressure hydraulics there High-Pressure Forming 4 logy and market leader Rexroth are enormous demands on the

works internationally not only with users, but also with the Research

static and dynamic drives – extreme forces act on the system and its

Hydraulic Clamping Device 6

Institute for Forming Technology components. This requires a sensi-

at the University of Stuttgart, on tive use in all aspects of safety, Hydromechanicalthe continuing development of this which Rexroth always fulfills over Clamping Device 8forward-looking technology. By and above the norm. All compo-

linking powerful hydraulic preci- nents and systems undergo various High-Pressure Components sion components with optimally stringent test and quality assurance

designed and matched open and procedures. Pressure Intensifier 10 closed loop control technology to

form highly efficient high-end Valve Technologysolutions, Rexroth systems are also Transducer 11achieving results in this field that

are setting standards the world over.

Axial Cylinder Open Loop Control MAC8 12

Open Loop Control HNC100-3XClamping Cylinder Control Valve TechnologyPump Control System

Drive Power Units 14

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Forming with Fluid Power:High-Pressure Forming

High-pressure form-ing opens up the possibility of produc-ing components thatare smaller and lighterthan comparable molded parts, and that also offer betterutilization of materialsand greater stability.

In the automotive industry we We differentiate basically betweencannot imagine life without this two methods of high-pressuremethod of hydroforming in the forming: internal high-pressurearea of chassis, engine and driving forming and hydromechanicalgear components. H owever, other deep-drawing.

sectors are also increasingly taking

advantage of the benefits of this technology: high-pressure forming

Internal high-pressure forming – Forming of sealed hollow bodies

is used, for example, in the manu- With internal high-pressure form-facture of drums and sud con- ing the tool consists of an uppertainers for washing machines and and a lower part. O nce the tool istumble dryers. clamped, hydraulic pressure acts

on the internal surface of the work-piece, which then expands and ispressed into the contour of the tool.

Internal high-pressure forming

Hydromechanical deep-drawing

Internal pressure

Work-piece, hollow bodied

Work-piece, flat sheet

Hydromechanical Deep-Drawing– Forming of Flat Sheets

Alongside internal high-pressure forming, hydromechanical deep-

Pressure transducer

drawing is also continually gainingin significance. W ith this processcomponents can be manufacturedin a single step, as opposed to con-ventional deep-drawing, whicheither requires several steps or, dueto the extreme drawing conditions,would not be possible at all from asingle component. Typical compo-nents from the automotive indus-try suitable for hydromechanicaldeep-drawing are extremely deep,contoured parts, such as tank shells, for example, as well as partswith a larger surface area such ascar roofs and engine hoods.

Another considerable advantage ofthis process is the high surfacequality of the manufactured parts.Unlike with conventional deep-drawing and internal high-pressureforming the tool here consists ofonly one half. The function of theother half is assumed by the me-dium under hydraulic pressure.

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Causes and Effect:

The Hydraulic Clamping Device

With both internal high-pressure form- ing and hydromecha- nical deep-drawing,

act in the opening directions of the tool. For this reason suit- able devices have to

Standardized press module with built-on proportional valve technology

a very high pressure be available to keepis generated inside the tool closed during

the tool. The expan- sion forces generated over the projected work-piece surface

the forming operation.

Such devices will be either hydrau-lic or hydromechanical clampingdevices. The hydraulic one is ableto generate the necessary clampingforce over the complete stroke. Inprinciple it corresponds to a simpleconventional hydraulic press.

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	FN					Principle of the hydraulic press: clamping device as upper piston and lower piston press
Rexroth – Guarantee of Operational Safety			• Main pump safety feature and pressureless bypass

Safety is one of the most important • Proportional press force settingcriteria in hydraulic press control • Redundant direction controlsystems –Rexroth is continuously with double safety feature againstsetting new standards in its deve- sinking and rising pressure oflopment: every press control – the compression piston, optionalwhether of smaller or larger size – speed, pressure or position controlcomplies with the safety regula- • Compression cylinder can betions of the employer’s liability additionally switched on and offinsurance association, as well as • Fast advance in free fallfulfilling the stringent criteria of • Regenerative circuit

DIN EN 693. The safety regulations • Fast advance up/down with rapidstipulated herein are applicable traverse cylinder not only in the European partner • Set-up in free fallcountries; they are recognized worldwide and often used as a base.

Rexroth realizes compact openloop control systems containingextensive safety functions includ-ing:

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The Plus for Force Clamping:

The Hydromechanical Clamping Device

	The hydromechanical clamping device can be distinguished from a purely hydraulic		The actual compres- sion stroke of the clamping device is relatively short and is
	one by its additional mechanical locking device, the purpose of which is to with- stand the forces gen- erated during the forming process.		used to pre-form the work-piece and close the two halves of the tool.			Features of a press with hydromechanical clamp: the bending force covers the complete stroke, whereas the nominal clamping force is not applied until after the mech- anical locking operation.

Hydromechanical clampingdevices with 35,000 KNnominal clamping force –a test installation for deve-lopment of new processingtechnologies. The hydraulichigh and low-pressure con-trol of this machine wasdeveloped in co-operationwith the University of Stuttgart.

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FN

This customer-specific compact control system, consisting of three separ- ate control blocks flanged together, is also designed to enable the blocks to be piped individually in the machine, thus positioning them as closely as possible to the cylinders.

In its product program Rexroth Swift movement through free fallalso has standardized control Both variants of retaining devicesystems for this type of press, for can be integrated into the hydrau-the compression stroke as well as lic directional control system, e. g.for the mechanical locking. These rapid traverse function by the presshave proven themselves already in plunger for downwards movementthousands of applications in con- in free fall. D uring this motion theventional presses and can easily be press cylinder sucks in more oilcustomized. It goes without saying from the tank, pre-fill valves beingthat every control system men- required for this.

tioned here complies with the rele- vant safety regulations.

These special valves operate at a high flow rate yet with an extremely low pressure differential. Rexroth components have been proving themselves particularly in this area for years now.

Sandwich plate pre-fill valve for inserting into cylinder base with built-on directional control valve

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Quality Down to the Finest Detail:

High-Pressure Components from Rexroth

Based on decades ofextensive know-howand excellent develop-ment potential Rex-roth has developedspecial high-pressurecomponents for hy-draulic systems to beused in high-pressureforming.

Pressure intensifiers • Pressures above 4,000 bar andPressure intensifiers from Rexroth other stroke volumes are alsohave been setting standards in this available on request.sector for years. Through con-

tinuous, forward-looking deve- With Rexroth pressure intensifierslopment they fulfill the stringent the low-pressure side is the controlrequirements of high-pressure side. A highly accurate flow rate oftechnology. The necessary media the high-pressure volume can beseparation of mineral oil on the achieved with the aid of the inte-low-pressure side and HFA on gral digital SSI position measuringthe high-pressure side takes place system, which can withstand pres-inside the pressure intensifier by sures of up to 500 bar, combinedmeans of special technical speci- with proportional valve technologyfications and specially developed on the low-pressure side.sealing systems.

Pressure intensifiers are standard- ized and available with the follow- ing technical specifications: • Ty pe CHP2 for operating pres- sures up to 2,000 bar and 1.38 to 7.85 liters stroke volume • Ty pe CHP4 for operating pres- sures up to 4,000 bar and 1,38 to 7.85 liters stroke volume

High-pressure transducer for pressures up to 5,000 bar

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Pressure intensifier withbuilt-on proportional andhigh-pressure valve tech-nology

f pok

High-pressure valve technology High-pressure transducer

As the pressure intensifier on the Special high-pressure transducershigh-pressure side cannot under- are used on the high-pressure sidetake the complete control operati- to measure the current pressure inon, special high-pressure valves are order to give a basis for the highused to steer the medium in the dynamic closed loop control ofright direction. A distributor block the pressure transducer. There are,and check valve are required to however, special requirements hereenable the pressure transducer to with respect to dynamic responsefill with H FA-fluid and then build and reproducibility of the pressureup pressure. The large diameters of transducer: Rexroth high-pressurethe Rexroth high-pressure valves transducers are equipped with aare of particular benefit here, as special thin-film sensory mechan-they permit a high flow rate yet ism, which meets these stringentwith low pressure loss. Time can requirements. The high stabilitybe saved above all when filling of of the sensors, combined with thethe pressure transducer. seamless weld measurement cell,

guarantee a high level of operation-al safety.

High-pressure distributorblock and check valve forup to 4,000 bar maximumpressure

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Quality Down to the Finest Detail:

High-Pressure Components from Rexroth

Pressure intensifier

P U

High-pressure port

Axial cylinder 2

Axial cylinders

These handle complex control tasks accurately and fast. These are prac- tically series type special stacking

S

U

PS2

U S

A

T cylinders – the valve control system

is flanged directly on the cylinder and stacked vertically. To enable

10µm

high response and traverse speedsto be attained, together with accur-ate positioning control, high dyna-mic response control valves, and insome cases, even servo valves, are used.

A P

M

MAC8

The digital Rexroth multi-axis NC

open loop control in modular design comprises a master card, which itself can control either two or four

M

axes. If necessary it can be extended

HFA Conditioning station

by up to four slave cards for four axes respectively. M AC8 thus offersthe optimum solution for complexopen loop control tasks with up to20 axes which can be interpolated.

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Clamping cylinder for bending force

X1

X2 X1.1

Locking device for

mechanical clamping

Accumulator for control axes

PD

Axial cylinder 1 PH

Work-piece B S U

P

S2

S1 TT

FN

Pressure cushion (cylinder) for nominal force FN

P1 X

P2

Pilot oilP3

Cooling water

Band filter

P1 P2 PH P3

M M M

PK

Mineral oil power unit

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Further MAC 8 devices can be con- Clamping cylinder The complete control function ofnected via local Ethernet. The An extensive standard cylinder the system is integrated into theMAC 8 communicates via Fieldbus program is available, with different closed loop control electronics of(Profibus DP or CAN) or via Ether- pressure ranges, piston diameters the pilot valve. Extremely short ad-net with the superior PLC machine from 25 to 500 mm as well as stroke justing times and excellent controlcontrol. It possesses special hydrau- lengths of up to 10 m. Deviations quality can be realized.lic closed loop control character- from standard dimensions and

istics, can control the machine pressures can be accommodated Drive power unitmovements completely indepen- without problem. The extensive standard programdently and thus also take on PLC for smaller and medium-sizefunctions. Sensors and actuators Closed loop valve technology hydraulic control systems is com-can be evaluated or controlled as The Rexroth range of proportional, plemented by user-specific driverelevant by means of CAN-Bus. control and servo valves leaves no power units, matched exactly to stone unturned. Rexroth is world- every requirement. Special noise-

HNC 100-3X wide leader in the development damping whispering power unitsThis scalable digital axis control is and manufacture of proportional can also be used, as can powera freely-programmable, bus-com- and control valve technology, in units designed for use with specialpatible NC control for both electro- particular for the high-pressure fluids.

hydraulic and electromechanical forming process. drives. It takes on sequential open

and closed loop control of up to Pump control system SYHDFEE four drives, as well as communica- For closed loop control of pres- tion with the superior PLC or PC sure and flow and thus optimum control. Optimum behavior of matching to the needs of the user. electrohydraulic drives is achieved There is also the option of power be means of open and closed loop control. The system comprises the control algorithms specially matched tried-and-tested swashplate axial to the characteristics of the hydrau- piston pump Type A4VSO, a built- lics. on proportional pilot valve and a

swivel angle transducer.

Industrial Hydraulics

Electric Drives andControls

Intelligent Hydraulics in New Dimensions		The Drive & Control Company Rexroth offers a unique and comprehensive range of pro- ducts and services across				Linear Motion and Assembly Technologies
			technologies in its six fields of technology and service areas – strong in high-quality individual technologies, combined with				Pneumatics Service Automation

highest application-specific com-

petence in system packages with Mobileintegrated complete solutions. Hydraulics

Wherever forces need to be utilized system solutions of high quality.economically, the advantages of in- With advanced micro-electronicsdustrial hydraulics are obvious – Rexroth has made hydraulics evenwhether it is required to lift and lo- more powerful.

wer loads smoothly, perform linear

or rotary movements, achieve con- For you, Rexroth is the ideal partnerstant acceleration, maintain given for developing highly efficientspeeds, approach positions exactly, machines and production facilitiestransmit powers or interlink se- – from the first point of contact toquences. commissioning and throughout the entire life cycle. Teams that operate

Rexroth is the technology and worldwide carry out the completemarket leader in industrial hydrau- engineering of your systems and,lics with a comprehensive product if requested, up to the hand-overrange and distinct application of turnkey systems and beyond –expertise. service included.

At Rexroth you can select from the Thanks to the use of hydraulicworlds’ largest standard product drive and control technology fromrange in the field of hydraulics, Rexroth you will be more competi-application and customer-specific tive than ever.

Rely on service across technologies

Rexroth integrates all services forthe entire product spectrum inthe field of factory and industrialautomation into a single organiz-ation: from immediate support,spare parts service, field andrepair service, retrofit/modern-ization through to training.

Bosch Rexroth AG Industrial Hydraulics Zum Eisengießer 1 97816 Lohr, Germany

Phone: +49(0)9352/18-0Fax: +49(0)9352/[email protected]

Printed in GermanyRE 09348/10.04

re09348