Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62D—MOTOR VEHICLES; TRAILERS
  • B62D5/00—Power-assisted or power-driven steering
  • B62D5/06—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle
  • B62D5/08—Power-assisted or power-driven steering fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle characterised by type of steering valve used
  • B62D5/083—Rotary valves
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/0318—Processes
  • Y10T137/0402—Cleaning, repairing, or assembling
  • Y10T137/0491—Valve or valve element assembling, disassembling, or replacing
  • Y10T137/0502—Multi way valve
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/8593—Systems
  • Y10T137/86493—Multi-way valve unit
  • Y10T137/86574—Supply and exhaust
  • Y10T137/86638—Rotary valve
  • Y10T137/86646—Plug type
  • Y10T137/86654—For plural lines

Definitions

• the invention relates to a method for mounting a steering valve with a centering unit for hydraulic power steering systems, in particular for motor vehicles, according to the preamble of claim 1.
• the steering valve contains a first valve element and a second valve element which can be rotated relative to one another.
• the centering unit contains a first centering element and a second centering element, which are rotatable relative to one another and displaceable relative to one another in the axial direction. At least one of the two centering elements can be acted upon by a spring in the direction of the other centering element.
• the centering elements have mutually assigned, essentially radially aligned grooves, between which rolling elements can be used.
• a steering valve with a centering device to which the method described above is known, is known from EP-Bl-646 080.
• the two valve elements and the two centering elements must be aligned and fixed very precisely relative to one another, so that the mechanical Center of the centering unit coincides with the hydraulic center of the steering valve.
• the second valve element is formed in one piece with the second centering element.
• the mechanical center of the centering unit is aligned with the hydraulic center of the valve elements by aligning the first centering element relative to the first valve element.
• the first centering element is relative to the non-rotating Ren axial lock initially rotated. After alignment, the parts are connected so that they cannot rotate. However, joining the parts by a welding process can result in undesirable local heating.
• the invention has for its object to provide an accurate and inexpensive assembly method.
• the process includes the following steps: The two valve elements of the steering valve are first aligned to their central position by means of a hydraulic or pneumatic pressure medium without a centering unit, and are connected to one another in this position by means of a torsion bar spring.
• the two centering elements of the centering unit are preassembled separately from the steering valve in an assembly device and aligned together with the rolling elements to their mechanical centering center, e.g. B. by applying an axial force.
• the two valve elements of the steering valve aligned with their central position are connected to the two centering elements of the centering unit aligned with their mechanical centering center.
• the first centering element is first aligned relative to the first valve element via a non-rotatable axial guide and connected to the latter in a rotationally fixed but axially displaceable manner.
• the second centering element is connected to the second valve element by means of a longitudinal press fit by axially displacing the entire centering unit along the non-rotatable axial guide.
• the second centering element has a radially outer circumferential groove in which an assembly tool can engage.
• the circumferential groove can be replaced by an assembly collar.
• the circumferential groove or the assembly collar are used both when aligning the parts and when assembling or pressing on. It is particularly advantageous if the circumferential groove on its wall facing away from the second valve element has an insertion cone for easier insertion of the assembly tool and if its wall facing the second valve element has an essentially flat surface for reliable support of the assembly tool.
• a roller bearing for example in the form of a needle bearing, can be arranged between the first and the second valve element in the axial region of the second centering element.
• FIG. 1 shows a longitudinal section through a steering valve with a centering unit.
• Fig. 2 is a partial view in the direction of arrow II in Fig. 1;
• Fig. 3 is a partial section according to section III in Fig. 1 in a second embodiment
• the invention is illustrated using the example of a power steering rack. With the same effect however, the invention can also be applied to ball nut power steering systems.
• a steering valve 1 in the form of a rotary slide valve is contained in a valve housing 2 of an auxiliary power steering system 3.
• the steering valve 1 contains a first valve element 4 in the form of a rotary slide valve, which is firmly connected to an input shaft 5.
• the first valve element 4 and the input shaft 5 are rotatably guided together in a second valve element 8 via roller bearings 6 and 7.
• the roller bearings 6 and 7 are expediently designed as needle bearings.
• the second valve element 8 is designed as a valve bushing and in turn is rotatably mounted in the valve housing 2.
• the second valve element 8 is also permanently connected to an output shaft 10, for example via a pin 9.
• the output shaft 10 carries a pinion 11, which is part of an otherwise not shown rack and pinion steering gear of the power steering 3. If the steering valve 1 is not used in a power assisted-rack steering system, but rather in a ball nut power-assisted steering system, the pinion 11 is replaced by a steering worm.
• the input shaft 5 and the output shaft 10 are connected to one another by a torsion bar spring 12, so that a limited rotation is possible between the input shaft 5 and the output shaft 10 and thus between the first valve element 4 and the second valve element 8.
• the pressure medium conveyed by a servo pump 13 is supplied to the respective work area of a servo motor 14 and is returned from the corresponding other work area to a pressure medium tank 15.
• the centering unit 16 contains two centering elements 17 and 18.
• the first centering element 17 is connected to the input shaft 5 and thus to the first valve element 4 in a rotationally fixed manner via a non-rotatable axial guide 20, but is axially displaceably connected to the axial guide.
• 20 has on the first valve element 4 and on the first centering element 17 mutually cooperating longitudinal grooves 21 and 22, between which balls 23 are inserted, which are expediently held in a ball cage.
• the second centering element 18 is non-rotatably and axially immovably connected to the second valve element 8 by a press fit. An annular shoulder with a cylindrical outer surface is worked out on the second valve element 8 for the press fit.
• the second centering element 18 has a cylindrical inner surface. The two cylindrical surfaces of the second valve element 8 and the second centering element 18 are connected to one another in a non-displaceable and non-rotatable manner by a press fit.
• Each of the two centering elements 17 and 18 has at least one groove 24 and 25, respectively, with inclined surfaces inclined in a V-shape with respect to one another, an arc-shaped or similarly shaped cross section.
• the grooves 24 and 25 are aligned essentially in the radial direction.
• a rolling element 26, for example a ball, is held between the grooves 24 and 25.
• the rolling element 26 is expediently guided in a cage 27.
• the cage 27 faces
• the spring 28 is designed as a helical spring, which, however, can be replaced by a metal bellows or another spring that is elastic in the axial direction, for example a package of leaf springs.
• the spring 28 is supported at its free end on a stop 29 which is formed on the first valve element 4, for example by a snap ring and a stop disk.
• the first centering element 17 is formed in one piece with a reaction piston 30.
• the centering element 17 and the reaction piston 30 can, however, also be made in two parts and then connected to one another.
• the presence of a reaction piston is not essential to the invention.
• the reaction piston 30 is sealingly guided on the input shaft 5 and in a valve bore 31 of the valve housing 2, the reaction piston delimits a reaction chamber 32, to which a servo pressure dependent on the steering force can be supplied via a line 33.
• the servo pressure can be influenced in a known manner by an electro-hydraulic converter 34 as a function of the driving speed and / or other parameters.
• the two valve elements 4 and 8 are in a hydraulic center position relative to one another.
• the two working spaces of the servo motor 14 are equal in pressure.
• the two valve elements 4 and 8 can be rotated relative to one another in both directions of rotation. This results in a pressure increase dependent on the angle of rotation in one of the directions of rotation. neten work space of the servo motor 14.
• the torsion bar 12 and the parallel centering unit 16 jointly align the two valve elements 4 and 8 to their hydraulic center position.
• the centering unit 16 is activated by those acting on its first centering element 17
• the second centering element 18 has a radially outer circumferential groove 35.
• the circumferential groove 35 has on its wall facing away from the second valve element 8 an insertion cone for easier insertion of an assembly tool.
• On its other wall, facing away from the second valve element 8, the circumferential groove 35 has an essentially flat surface for reliable support of the assembly tool.
• an assembly collar 36 can be provided, as is shown in FIG. 3.
• the method for assembling the steering valve 1 with the centering unit 16 is described with its individual steps: First, the two valve elements 4 and 8 without the centering unit 16 are aligned to their central position by a pressure medium and in this position with each other via the torsion bar spring 12 connected. The alignment can be done with a hydraulic or pneumatic pressure medium.
• the two centering elements 17 and 18 of the centering unit 16 are separated from the steering valve 1 in one assembly. days device pre-assembled and aligned with the rolling elements 26 to their mechanical centering. This alignment takes place, for example, by applying an axial force.
• the spring 28 can be used for this.
• valve elements 4 and 8 aligned with their central position are connected in two steps to the two centering elements 17 and 18 aligned with their mechanical centering center.
• the preassembled centering unit 16 is first pushed onto the first valve element 4 and its first centering element 17 is aligned relative to the first valve element 4 by the axial guide 20. It is essential that the axial guide 20 serves both for mounting and for operating the steering valve 1 with the centering device 16. As a result, the centering unit 16 is already connected to the first valve element 4 in a rotationally fixed but axially displaceable manner.
• the centering unit 16 with its second centering element 18 is pushed onto the second valve element 8, so that the second centering element 18 with the second valve element 8 is connected via a longitudinal press fit.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Power Steering Mechanism (AREA)
• Automatic Assembly (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=7842284

Family Applications (1)

Country Status (9)

Families Citing this family (11)

Citations (2)

Family Cites Families (7)

• 1997
  • 1997-09-13 DE DE1997140352 patent/DE19740352A1/de not_active Withdrawn
• 1998
  • 1998-09-09 BR BR9812202A patent/BR9812202A/pt not_active IP Right Cessation
  • 1998-09-09 JP JP2000511671A patent/JP2001516672A/ja not_active Ceased
  • 1998-09-09 ES ES98951363T patent/ES2168797T3/es not_active Expired - Lifetime
  • 1998-09-09 EP EP98951363A patent/EP1012027B1/de not_active Expired - Lifetime
  • 1998-09-09 CN CN98808839A patent/CN1087699C/zh not_active Expired - Fee Related
  • 1998-09-09 WO PCT/EP1998/005700 patent/WO1999014098A1/de not_active Ceased
  • 1998-09-09 DE DE59802261T patent/DE59802261D1/de not_active Expired - Lifetime
  • 1998-09-09 US US09/508,263 patent/US6267133B1/en not_active Expired - Lifetime
  • 1998-09-09 AU AU97419/98A patent/AU726600B2/en not_active Ceased

Patent Citations (3)

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