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
  • B62D5/0837—Rotary valves characterised by the shape of the control edges, e.g. to reduce noise
• • 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

Definitions

• the present invention relates to a rotary valve according to the preamble of claim 1.
• Power Steering Rotary Valves typically include two valve elements coaxial with one another
• movably arranged and limited to achieve a control path are arranged rotatable to each other.
• a first valve element which is connected to a valve input member, formed as a radially inner rotary valve.
• a second valve element is non-rotatably connected to a valve output member designed as a drive pinion and designed as a radially outer control bush.
• the rotary valve is additionally connected to the drive pinion via a backlash limiting a control path.
• Both valve elements have control longitudinal grooves which at least extend to A part are limited in their axial extent and serve to control a pressure medium from or to Hähoff ⁇ men of a hydraulic actuator or servomotor.
• a torsion bar spring To reset the two valve elements from a deflected position into its neutral or Mitten ⁇ position is a torsion bar spring.
• Such Drehschie ⁇ berventile are known for example from DE 1227350, DE 4108597, DE ' 19921745, DE 19961017, DE 10146792.
• These rotary slide valves are known both as “open center” and as “closed center” valves.
• control edges of the control longitudinal grooves are indispensable bars.
• control edges of the opening cross-section of the rotary valve can be specified as a function of the angle of rotation between the valve spool and valve sleeve.
• costly and expensive production processes are necessary.
• the inner longitudinal grooves of the valve bushings are complicated and cost-intensive in their production.
• the object of the present invention is to provide a rotary slide valve which is simpler to manufacture.
• the radial channels of the valve sleeve can have an arbitrarily shaped opening cross-section.
• the opening cross sections or the cross sections of the channels can be eroded or cleared, for example, simply and inexpensively. Other methods of making the channels are of course also possible. It is advantageously possible to dispense with specially shaped internal control edges which are complicated to manufacture in the valve bushing.
• valve sleeve is displaceably mounted in the radial direction by the same pressures in the grooves of the valve bush and the valve rotary valve to be suitably selected.
• the radial play which is important for the sealing action of the valve is advantageously kept small in the initial state or in the middle position, since an increase in friction is compensated by the play compensation.
• the rotary valve of the invention is also advantageously simple and compact in its Auf ⁇ construction.
• the rotary vane valve should advantageously be designed as a closed-center valve ( vv closed-center)
• a hydraulic pump with maximum pressure and minimum delivery volume can be used, whereby the rotary valve
• the rotary slide valve according to the invention is of course also possible to use the rotary slide valve according to the invention as a valve with an open center. to design.
• the channels in the valve sleeve, the radially encircling channels and the axial channels are to be arranged accordingly and keptstge ⁇ in their cross-section kept ⁇ .
• valve sleeve of known rotary slide valves has additional axia ⁇ le grooves, which are arranged on the inner wall of the valve sleeve an ⁇ and complicated to manufacture, since they must work together exactly with the axial grooves and their control edges of the valve rotary valve.
• the erfindungsge ⁇ Permitted rotary valve dispenses with this complicated interaction of the axial grooves of Ventild ⁇ reed valve and valve sleeve ange ⁇ are arranged by radially circumferential grooves and axially extending grooves in the valve rotary valve, which in cooperation with the channels of the valve sleeve, the individual valves of the rotary valve form.
• the radially encircling grooves are interrupted at least once by at least one web, the webs or interruptions closing or partially or completely opening one or more channels of the valve bush in certain positions.
• the mallli ⁇ Chen boundaries of the axially extending grooves of the Ven ⁇ tilwindschiebers also serve to close a corresponding with the axial groove channel of Ventil ⁇ bushing.
• the interior of the valve sleeve is advantageously formed by the contour on the valve Rehschieber particular metallic against the Hä ⁇ pressure at the valve inlet or inlet sealed.
• the two working chamber connections of the rotary slide valve are connected in this position via a further valve inlet to the reservoir.
• the inlet cross section or opening cross section is successively released, as a result of which a volume flow begins to flow.
• the working space connection to be pressurized is sealed off from the reservoir, while the second working space connection remains connected to the reservoir.
• the rotary slide valve can be designed such that a part of the volume flow coming from the inlet past the working space connection is led back directly into the reservoir.
• the volume flow through the supply and reservoir-side control contours in the valve sleeve and the axial groove in the valve rotary valve is throttled according to the specifications, whereby almost be ⁇ arbitrary throttle cross-sections are possible and, as already explained, the shape of the valve characteristic can be influenced almost arbitrarily.
• FIG. 1 shows a schematic representation of a hydraulically assisted steering
• FIG. 2 is' a plan view of an inventive
• FIG. 3a and 3b two perspective views of the valve rotary valve according to the invention
• Fig. 4a cross-sectional view through the section
• FIG. 4b shows an enlarged detail of the cross-sectional representation according to FIG. 4a;
• FIG. 4c shows an enlarged detail of the cross-sectional view according to FIG. 4a in a slightly rotated position of the rotary valve valve
• Fig. 5a cross-sectional view through the section B-B acc. Fig. 2 in the middle position of the rotary valve;
• FIG. 5b enlarged detail of the cross-sectional representation according to FIG. 5a;
• Fig. 5c shows an enlarged detail of the cross-sectional view according to FIG. 5a in a slightly rotated position of the rotary valve valve
• Fig. 6a u. 6b Sectional views of the section D-D acc. Figure 2 in a slightly rotated position of the rotary valve.
• FIG. 1 shows a schematic representation of a hydraulically assisted steering system, showing a steering handle L, wherein the rotary slide valve 1, 1 'is arranged between the pinion 3 and the handle L.
• the rack 4 is operatively connected to the double-acting two-sided Kol ⁇ benstangenzylinder H, whose cylinder is divided by the piston K in two working spaces A and B.
• the outputs A A and A B of the rotary slide valve 1 are connected via lines to the work spaces A and B.
• the rotary slide valve 1 is shown for schematic reasons as a 4/3-way valve, which is brought from the torsion bar T in the unloaded state in the center position.
• valve input E P is connected via a valve in the rotary valve integrated throttle valve via the valve inlet E R to the reservoir R, which then simultaneously a valve outlet with the Venti ⁇ input Ep and the other connected to the reservoir.
• the rotary valve 1 shown in Figure 1 is designed as a "closed-center" valve, wherein the Hydraulik ⁇ pump P is driven by a motor P M , which can be operated with maximum pressure and minimum delivery volume.
• FIG. 2 shows a plan view of a rotary slide valve according to the invention without the enclosing housing.
• the valve inlets and valve outlets arranged in the housing are connected to the outer, radially circumferential grooves 7a-7e of the valve bush 6.
• the grooves 1a-1e are separated from each other by the peripheral lands 71, 7m, 7n and 7o arranged between them.
• the grooves 7b and 7d are connected via the valve housing with the valve inlet E P , to which the pressure side of the hydraulic pump P is connected.
• the central groove 7c is connected to the valve inlet E R , to which the reservoir is connected.
• the Ventil ⁇ bushing 6 encloses the valve rotary valve 5 sealingly, wherein the interior of the valve sleeve 6 is connected via the arranged in the valve sleeve 6 in the region of the grooves Ia-Ie channels.
• annular seals can be arranged for sealing against the inner wall of the housing.
• FIGS. 3a and 3b show perspective views of the inventive valve rotary valve 5 from different directions, so that the individual webs S A , S B as well as grooves NR A , ND A and NR B , ND B can be seen.
• the valve rotary valve 5 has four radially circumferential grooves 5a-5d, which correspond via the channels of the valve sleeve 7 with the outer circumferential grooves Ia-Ie of the valve sleeve kor ⁇ .
• the grooves 5a-5d are bounded axially laterally by the webs 5h, 5e, 5f, 5g and 5j, wherein the radial outer walls of these webs are metallically sealed against the inner wall of the valve sleeve 6.
• the grooves 5a and 5b are connected to each other via an opening 5o of the web 5e.
• the groove 5b further comprises an axial web S B which selectively opens or closes a channel P B (see Figures 2 and 6a, ⁇ b).
• the grooves 5c and 5d are connected to each other via an opening 5p of the web 5g.
• the groove 5c like the groove 5b, has an axial web S A , which optionally opens or closes a channel P A (see Figures 2 and 5a, 5b, 5c). Both axial web S A and S B are arranged so that they close the corresponding channel P A and P B of the valve sleeve 6 in the center position.
• the width of the axial webs S ⁇ and S B is dimensioned such that always at least one channel P A or P B is closed for all twist angles.
• the axial webs do not have to completely interrupt the radial circumferential grooves.
• the web S A , S B must be dimensioned only by its cross-sectional area so that it completely closes or opens the channel for the erforderl ⁇ chen Verwind ⁇ angle ranges.
• the central web 5f has two groups of two axially extending grooves NR A , ND A and NR B , ND B , wherein the axial grooves NR A , ND A form a group which, starting from the groove 5 c in extend in the axial direction in the web 5f inside.
• the axial grooves NR B , ND B form the second group and extend from the groove 5 b in the axial direction into the web 5 f inside. All axial grooves NR A , ND A and NR B , ND B terminate in the region of the web 5f and are therefore only open on one side.
• the axial grooves NR A , ND A and NR B , ND B and the axial webs S ⁇ , S B are in principle arbitrarily about the circumference of the valve rotary valve 5 can be arranged, of course, the corresponding channels eben ⁇ if appropriate was ⁇ arranged in the valve sleeve 6 have to.
• Figures 4a to 4c, 5a to 5c, and ⁇ a and 6b show the sections AA, BB and DD of the valve rotary valve gem.
• Fig. 2 both in the center position and in ver ⁇ rotated positions.
• Table 1 shows an overview of the respective valve positions as a function of the angular position ⁇ of valve rotary valve 5 and valve bushing 6.
• Figures 4a and 4b show the rotary valve in its center position, which is defined by the unloaded Tor- sion rod T.
• the relative positioning and fixing of the valve sleeve 6 and the valve rotary slide 5 to one another is well known and can also be used for the rotary slide valve according to the invention.
• the groove ND A and the associated channel R iae and the groove ND B and the zu ⁇ associated channel Ri B do not overlap, ie the cylin ⁇ drical outer wall of the web 5f closes metallic channels sealing the channels R ⁇ a and Ri B.
• the valve closes NR ⁇ -R 2A and the valve ND A -RiA opens.
• the valve S A -P A opens (FIG. 5 c), whereby the groove 5 c is connected to the pressure side of the hydraulic pump P.
• the valves S 6 -P B and ND B -R IB remain closed, whereas the valve NR B -R 2B continues to open.
• the volume flow now flows via P A into the groove 5c, from where it flows via the passage 5p into the groove 5d and through the passage 7h (FIG.
• valve ND A -R ⁇ A thus serves as a throttle valve via which the valve characteristic can be influenced. If the rotary slide valve is rotated in the other direction, the valves open or close analogously.
• FIGS. 7a and 7b show by way of example the interaction between the axial groove ND A of the valve rotary valve 5 and the radial channel Ri A of the valve bushing.
• FIG. 7a shows the valve in the middle position
• FIG. 7b shows the valve in the rotated position.
• the opening cross section of the channel Ri R can in principle be designed as desired, so that the opening cross section of the valve ND R -Ri A changes over the angle of rotation ⁇ .
• the opening cross section is to be adapted to the desired valve characteristic curve.
• the channel R ⁇ A as well the other channels of the valve sleeve can be produced with a variety of manufacturing processes.
• FIG. 8 shows possible opening cross sections of a channel R IA ', Ri a ''orRIA'' of the valve bushing 6.
• the number of channels and grooves deviates from the embodiment explained above. Their arrangement can be reversed. Furthermore, it is also possible to dispense with the openings of the webs for connecting the grooves 5a, 5b or 5c, 5d, in which corresponding channels are arranged in the valve bushing. Thus, it is also possible, for example, to replace the breakthrough by an internal channel running through the valve rotary valve, for example in the form of a through-bore. Also, the axial channels do not have to be exactly axial, but can also be arranged obliquely to the axis. Furthermore, they need not necessarily have a straight course.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Multiple-Way Valves (AREA)
• Sliding Valves (AREA)
• Power Steering Mechanism (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

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ID=34972251

Family Applications (1)

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Citations (2)

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• 2004
  • 2004-07-13 DE DE200410034026 patent/DE102004034026B4/de not_active Expired - Fee Related
• 2005
  • 2005-06-14 DE DE502005002845T patent/DE502005002845D1/de not_active Expired - Lifetime
  • 2005-06-14 WO PCT/EP2005/006336 patent/WO2006005403A1/de not_active Ceased
  • 2005-06-14 EP EP05751722A patent/EP1765656B1/de not_active Expired - Lifetime

Patent Citations (2)

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