DE10046416C2 - Valve design for control valves - Google Patents

Abstract

Valve configuration for control valves comprises a valve seat between a high pressure inlet and a blocking element (7) on the low pressure side which in its closed position is centered over the seat contact zone. A receiving chamber (16) limited on the lower pressure side is assigned to the blocking element on the seat contact zone. Preferred Features: The blocking element forms a component connected to an adjusting movement device (9).

Description

The invention relates to a valve design for control valves according to the preamble of claim 1.

Corresponding to the injection systems for internal combustion engines, to master in particular storage pressure injection systems the very high pressures up to the order of 2000 bar there are growing problems for their control valves, because the valves lying between the high and low pressure side with their locking elements against the high pressure side are exposed to very high loads. In particular leads the pressure drop between high and low pressure side in the Throttle point for high flow rates with the Ten the flow cavitation with increasing pressure drop in the exit area on the locking member, with the opening hit the locking member because of the associated deflection pressure and flow delays gives. This favors the imploding of the cavitation bubbles in the seat contact area of the locking member and the seat of the Valve seat and causes corresponding cavitation erosion. This affects the locking element and the valve seat those areas that, due to their function, also have the highest mechanical Exposed to loads, such as through impact act upon the impact of the locking member on the Valve seat and by aligning the locking member opposite the seat at the cent associated with the closing process ration of the locking member opposite the seat.  

It is over to reduce such cavitation phenomena JP 012 69 780 A, abstract, which in the preamble of claim ches 1 is known, the conical locking member graduated, such that both sides of its conical Sealing surface cylindrical ring zones are given in the axial Cover to cylindrical, on both sides of the valve seat orderly, housing-side recordings, so that subsequently ßend to the resulting sealing limit radially narrow ring spaces are given as throttling sections. This is applied Locking element via an actuator in the form of a Diameter to the locking member radially reduced control rod, the centering the locking member against the valve seat over the conical sealing surface enables. In connection with the center tion over the sealing surface in the sealing limit and - when open ter sealing limit - given over the circumference of the locking member Non-uniformities in the overflow of the blocking member can With such a solution, vibrational excitations occur that can lead to fluctuations in the amount of overflow, and thus the time behavior influence the control valve, and which can also lead to disturbing noises.

Furthermore, a control valve is known from DE 196 24 001 A1, its locking member, pressurized in the closing direction, with its conical sealing surface in a Ven tilsitz is pressed, in the high pressure side inlet and in low-pressure side outlet throttle sections and connected to the locking member, housed and as an actuator rod-shaped actuator. Because of the pressure loading of the locking member in the direction of its closing location should make better use of the work capacity of the Actuator assigned to the blocking element piezo element regardless of the shape of the locking member, the spherical, conical, or also designed as a double cone can be, with a fixed or only supporting Ver binding of the locking member with the actuator.  

Another, the DE 197 32 802 A1 and also not the previous one published DE 199 46 833 A1 embodiment of a Control valve provides for timed control of the injection a piezo actuator that has a stroke ratio that at the same time tolerance compensation function, the locking member acted upon the two axially opposite lock locations are assigned. These blocked locations, in which the block link against one of the axially opposite one another Valve seats are present, correspond to an injection injector opening positions of the injector, and there are over control the piezo actuator also intermediate layers for the locking member erbar in which the injection is interrupted, so that have different injection profiles designed.

From DE 44 02 752 A1 it is known for radiator valves to improve these in terms of valve noise in that a first, formed between the valve seat and locking member Throttling point, a second throttling point is connected downstream, by a gap axially offset from the valve seat between an annular surface surrounding the valve seat and one housing-side end face is formed.

For hand-operated check valves, US 3,529,805 provides as Locking member a ball segment, possibly with in the of the Conical opening protruding through the seat to use the tenon in a front recess tion of the actuator is held radially and axially ü over the flattened against the actuator is supported, so that the locking member only around its to the seat vertical axis is rotatable and thereby one to the seat has corresponding, predetermined contact zone.

US 5 381 999 shows a control for an injection injector valve, which acts as a blocking element via an actuator  has loaded ball, the low pressure side to the valve seat, the throttle section on the high pressure side is upstream, and in which the travel of the actuating movement assigned to the adjustment of the anchor air of this th magnetic actuator is limited. The anchor plate lies in the flow path of the throttled, running over the blocking member Connection to the low pressure side, this connection being central is guided by the magnetic actuator.

EP 0 994 248 A2 shows a piezo actuator Beaten control valve of an injection injector, its housing is modular and in which the high-pressure side tax chamber and the actuator different, consecutive Mo are assigned to modules. In the transition between these modules is the controlled, formed by locking member and valve seat Connection from the high pressure side to the low pressure side, whereby the low pressure side connection duct in the interface of the two successive modules runs radially.

Furthermore, a control valve is known from DE 196 15 888 A1 Pressure reduction of gaseous substances known, in which with a axially displaceable to the center axis of the valve seat, cont rated control cone is worked as a blocking element and at the Measures for primary noise reduction by the throttle operation caused noise emission are provided. The Ven For this purpose, tilsitz is located at the narrowest passage cross cut with a cross-sectional extension that into a further, ring-shaped, axially ver current niches or holes formed in Extend flow direction. This is said to have a high E energy emerging from the narrowed acceleration section Gas jet are shaped so that its surface increases esser, for faster mixing with that in the extension located medium, which reduces the vibration excitation shall be.  

Finally, DE 39 30 757 A1 is a valve in particular known for slip-controlled hydraulic brake systems, in which the spherical lock to reduce operating noise link asymmetrical circumference with pressurized guide tion surfaces is provided to a when the locking member is open Achieving desaching opposite the valve seat the noise behavior during the valve switching phase should improve, in addition, a golf ball-like structure ration of the surface of the locking member outside of its loading Stirring surface is provided for the valve seat.

The invention is based on the object with a valve education of the type mentioned at the outset, that of the danger from To counteract cavitation erosion, create a solution fen, the mechanical stresses between locking member and valve seat reduced.

This is achieved by the features of claim 1, wherein through the spherical, facing towards the seat tapered shape of the locking member the aimed tiered Throttling with simple means and little effort to reali sieren is because favorable conditions for both the Abdich to the valve seat as well as in the equatorial sliding guide are created. Due to the equatorial guidance of the ball shaped locking member are also the prerequisites for this given the actuator in its dimensioning to be designed solely for the axial forces to be supported, so that the mass of the locking member and actuator is small can be held, which also with regard to the dimensioning the actuator acting on the actuator and desired short tax times is appropriate. Furthermore, the Sliding guide for the locking member in coaxial alignment the inclusion on the valve seat and the given high bear machining accuracy with small tolerances after a short running-in period  for a constant positioning with good ab seal, the sealing sliding guide of the locking member in the cylindrical holder in combination with an over bridging channel connection also the constructive design expanded space, especially with regard to the training of the Dros additional cross-sections also opened up.

In the context of the invention, the locking member as an independent Be formed component, but also as with the actuating movement Transmitter connected component, since the by the invention of radial leadership tasks lean lean interpretation of the Actuator, if necessary, also the compensation ra allows tolerances.

On the flow conditions following the high pressure egg The throttling point can be adjusted to the contour of the Locking member in the context of the invention also by the design the seat influence, and this in particular in ver binding with the design or positioning of the bridg sewing channel connection, with appropriate assignment of seat and cylindrical seat, if necessary separate housing parts, also in this regard without disadvantages Various design options for the overall concept are given.

In particular, within the scope of the invention also with simple Average the throttle cross-section of the abge through the sliding guide limited space dependent on the stroke of the locking member who the, that is, a Dros variable in cross-section depending on the stroke can be created without the associated Effort could question the overall concept.

Further details and features of the invention emerge from the claims. Furthermore, the invention is set forth below hand of an embodiment explained in more detail. Show it:  

Fig. 1 is a schematic sectional view of the control valve of an injection injector, between the nozzle part and an opposing to this arranged magnetic actuator, the control valve, the magnetic actuator on the control valve acts on a stroke actuator for the locking member, which controls a throttled inlet from a pressure chamber with which the nozzle needle of the injection nozzle, which is acted upon by the injection medium in the opening direction on the high-pressure side, is connected to an application surface via which the nozzle needle is loaded in addition to the closing spring in the closing direction when the pressure in the pressure chamber is present,

Fig. 2 shows an enlarged detail of a portion A of FIG. 1, showing the locking member constricting beaufschla actuating movement transmitter and the related contractual area of the valve seat,

Fig. 3 is a FIG. 2 corresponding inventive design of locking element and an associated valve seat portion,

Fig. 4 shows a section according to IV-IV in Fig. 3 in schemati lized representation,

Fig. 5 and 6 show further embodiments of the invention in one of the Fig. 4 corresponding representation, where alog to Fig. 4, the locking member between zugehö engined seat and axially spaced sliding guide comprises a region with branching off from the seat surface region of the actuator orifices having o of throttle channels,

7 shows a further embodiment according to the invention in which the Dros formed by recesses selquerschnitte of the axially movable blocking member are placed. In the region of the sliding guide,

Fig. 8 is a sectional view according to line VII-VII,

Fig. 9 shows another embodiment of the invention, in which the throttle cross sections formed by recesses are variable depending on the stroke of the locking member, and

Fig. 10 is a schematic sectional view according to Li never XX in Fig. 9.

In Fig. 1, the control valve 1 of a not shown Darge injector is illustrated, via which the injector associated with the injector is controlled. The high pressure side inlet connection to the control valve 1 is illustrated by the arrow 2 . The inlet takes place via a bore 4 provided in a valve plate 3 , which opens out onto a valve seat 6 via a throttle point 5 .

The valve seat 6 tapers in the direction of the bore 4 , that is, counter to the inflow direction according to arrow 2 , and the valve seat 6 is assigned a locking member 7 which is supported in a stroke-movable manner (arrow 8 ). The support of the locking member 7 he follows in the embodiment ( Fig. 1) via a Stellbewe supply transmitter 9 , which is designed as a rod-shaped, thin actuating plunger and which is based on the Steuer erventil 1 to the direction of flow according to arrow 2 opposite via a magnetic actuator, not shown here the injector is loaded and adjustable.

In the closed position, the locking member 7 is seated in a seat contact zone 10 on the valve seat 6 , to the low-pressure side, a cylindrical receptacle in the form of a bore 11 in the valve plate 3 connects, into which the locking member 7 supported via the actuating transmission 9 plunges and the , based on FIGS. 1 and 2, a portion of the low-pressure side Abströmwe ges forms which can be seen in Fig. 1 len, in Querkanä 12 continues, the range between the valve plate 3 and the housing 13 of the control valve 1, whereby in the embodiment, the valve plate 3 is centered and fixed against the housing 13 via a clamping ring 14 .

In connection with the high pressure on the high pressure, there are very high flow velocities, based on the opening position of the blocking member 7 , which is not shown, when flowing through the throttle point 5 , which cause cavitation of the flow due to the transfer of the flow medium to the low pressure side due to the pressure drop can, where the cavitation bubbles when they hit the locking member 7 and the locally associated deflection and flow delay can implode, which can lead to locking member 7 and valve seat 6 for cavitation erosion.

This is where the invention comes in, as explained with reference to FIGS . 3 to 9 below, the same reference numerals being used for the same parts.

Fig. 3 illustrates that the locking member 7 formed in the exemplary embodiments as a spherical segment has a diameter matched to the drilling 11 , such that there is a radial sliding guide through the bore 11 in the center plane 15 of the locking member 7 parallel to the seat contact zone 10 , which, although the stroke mobility - according to the arrow 8 - of the locking member 7 in the sense of a low-friction sliding guide, as a result of the guide serving as a gap seal but delimits a seating area 10 formed by a space 16 , from which the connection to the low pressure side throttled follows. This throttled connection is illustrated in FIG. 3 via throttle bores 17 , which open out onto the space 16 adjacent to the valve seat 6 and which radially fen to the stroke axis 18 of the actuator 9 .

In the transition from the high-pressure side (arrow 2 ) to the low-pressure side - symbolized in FIG. 3 by the arrows 19 - two throttling points follow one another, so that a staged pressure reduction with a correspondingly lower pressure drop at the throttling point 5 in the inflow onto the blocking member 7 results, whereby the conditions with regard to the occurrence of Ka vitationserosion are significantly mitigated.

The provided axial sliding guide for the locking member 7 , by means of which the space 16 is delimited between the seat surface 10 or throttling point 5 and downstream throttling bores 17 , also contributes to the locking member 7 also holding one of its locking position in its position lifted from the valve seat 6 Ent speaking centering maintains what contributes to the stabilization of the flow conditions on the locking member 7 and the flow conditions with respect to the locking member 7 and also reduces the mechanical stresses between locking member 7 and valve seat 6 in that deviations in the axial position are at least largely avoided.

The centering guide function for the spherical, in the direction of the valve seat tapering locking member 7, it has proven to be useful if the locking member 7 is firmly connected to the actuating motion transmitter 9 , or, without centric connection to this, is only acted upon. Furthermore, the management function proves to be useful in connection with full spherical locking members, or also formed as a ball segment locking members, wherein in the game Ausführungsbei a ball segment is provided as a locking member 7 .

FIGS. 5 and 6 represent solutions which functionally speaking ent, which with reference to FIGS. 3 and 4 has been explained. 3 and 4 in the structural design, they differ from the solution according to FIGS . 3 and 4 by the type of implementation of the connection of the space 16 to the low-pressure side via corresponding throttle bores or throttle ducts, throttle ducts 20 being provided in the embodiment according to FIG open out from space 16 to the low pressure side (arrow 19 ), where in FIG. 5 the throttle channels 20 are formed in that a valve plate 21 is provided, to which a cover plate 22 is assigned, valve plate 21 and cover plate 22 facing one another Surfaces form the throttle channels 20 , which are incorporated in the cover plate 22 , in the valve plate 21 or in both plates and which run in the partial plane 23 of the two plates. The part plane 23 corresponds to the sectional plane between the bore 11 and the conical valve seat 6 , so that the bore 11 runs in the cover plate 22 and the valve seat 6 is incorporated in the valve plate 21 . Overall, this leads to a simplified structure.

Fig. 6 is again based on a division into a valve plate 24 and a cover plate 25 , as it was explained with reference to FIG. 5. The valve seat 26 is also incorporated in the valve plate 24 , the bore 11 is assigned to the cover plate 25 and passes through it, opening out within the diameter of the valve seat 26 on this. Accordingly, the widening in the flow direction according to arrow 2 the valve seat 26 has a radial overlap region to the cover plate 25, wherein the dividing plane between the valve plate 24 and cover plate 25 be 27 is distinguished and is offset opposite to the direction of flow 2 to the center plane 15 of the locking member 7, the axially The area of the bore 11 lies, so that in this solution, too, the sliding guide for the locking member 7 lies in the area of the bore 11 , in FIG. 5 in the area of the cover plate 22 and in FIG. 6 in the cover plate 25 . The fact that the diameter of the bore 11 as a cylindrical receptacle for the locking member 7 is smaller than the diameter of the conical valve seat 26 in the region of the part plane 27 , the space 28 is partially covered by the side of the cover plate 25 facing the valve plate 24 , so that on the space 28 the cover plate 25 axially penetrating throttle bores 30 can open out. The invention thus shows a wide variety of connection options of the respective room 16 or 28 to the low pressure side, so that corresponding constructive requirements can be taken into account within the scope of the invention.

Another possibility of the throttling connection to the low pressure side is shown in FIGS . 7 and 8, with an initial situation also being given here as it corresponds in principle to the construction according to FIGS. 3 to 6. The valve plate 31 , as an inlet on the high-pressure side according to arrow 2, in turn has a bore 4 , which opens out centrally via a throttle point 5 onto the valve seat 6 , which in the closed position of the blocking member 32 is covered by the latter. In this exemplary embodiment, a spherical segment is also provided as the locking member 32 , the central plane 15 of which runs parallel to the seat contact surface 10 and which is guided axially displaceably in the region of the central plane 15 and lies sealingly against the wall of the bore 33 as a cylindrical receptacle, which acts as a guide bore for the locking member 32 adjoins the seat surface 6 and delimits the space 34 from the seat surface 6 together with the locking member 32 . The locking member 32 is supported in this case also via an actuating transmitter 9 , which can be moved in accordance with the arrow 8 . As illustrated in FIG. 8, the space 34 is connected to the low-pressure side via axially extending recesses, which are provided in the circumference of the bore 33 and are designated by 35 and which extend in the direction of stroke movement (arrow 8 ) on both sides of the central plane 15 , such that Analog to the Drosselboh stanchions 17 or the throttle channels 20 or the throttle bores 30 , regardless of the respective stroke position of the locking member 32, there is a throttling connection of the space 34 to the low pressure side. For this purpose, it may be expedient to design the actuating movement transmitter 9 designed as an actuating rod as a punch smaller in diameter than the blocking member 32 , so that the incorporation of further channels or bores is unnecessary.

Based on a basic design according to FIGS. 7 and 8, FIGS. 9 and 10 show an embodiment in which in turn one works with a locking member 36 designed as a spherical segment, which in the region of its center plane 15 parallel to the seat contact zone 10 on the wall of the bore 39 abuts, which serves as a sliding guide for the locking member 36 and the locking member 36 delimits the space 37 with respect to and the subsequent valve seat 6 . This are in the direction of the low-pressure side opening discharge cross-sections assigned, which are sections as throttle cross-sections in the size of their cross-sectional area of the Hubstel development of the locking member 36 dependent. These stroke variable union throttle cross sections are formed by recesses 40 in the circumference of the bore 39 , which can be designed according to the desired throttle behavior. Thus, in FIGS. 9 and 10 as an example of an embodiment illustrated, the recesses are in the closed position of the locking member 36 largely to off 40 on the locking member 36 at least in and released only with increasing opening stroke.

Various possibilities are therefore within the scope of the invention given a stepped throttle transition from high to never derdruckseite for control valves of the type described to rea lize, both with regard to cavitation erosions such as also with regard to the mechanical wear of the locking member and valve seat solutions are created that last and last Improve the reliability of the control valve.

Claims (22)

1.Valve training for control valves of injection injectors, in particular for large-volume internal combustion engines operated with diesel or heavy oil and working with accumulator pressure injection, with a valve seat which is located between the inlet on the high-pressure side and the low-pressure side locking member acted upon by an actuating motion transmitter, with a high-pressure side and a low-pressure side the throttle point associated with the valve seat, with centering of the locking member on the valve seat and with a cylindrical receptacle assigned to the valve seat and assigned to the locking member, characterized in that the locking member ( 7 ; 32 ; 36 ) is spherical and spaced apart from the valve seat ( 6 ; 26 ) is centered over an equatorial sliding guide in the cylindrical receptacle (bore 11 ; 33 ; 39 ) and that the throttle valve on the low-pressure side bridges the sealing limit formed by the sealing center Ka nalverbindung (throttle bore 17 ; 30 ; Throttle channel 20 ; Recesses 35 ; 40 ) lies. 2. Valve design according to claim 1, characterized in that the locking member ( 7 ; 32 ; 36 ) forms a component independent of the actuating movement transmitter ( 9 ). 3. Valve design according to claim 1, characterized in that the locking member ( 7 ; 32 ; 36 ) forms a component connected to the actuating motion transmitter ( 9 ). 4. Valve design according to one of claims 1 to 3, characterized in that a ball segment with the Stellbe motion transmitter ( 9 ) associated flat side is provided as a blocking member ( 7 ; 32 ; 36 ). 5. Valve design according to one of the preceding claims, characterized in that the valve seat ( 6 ; 26 ) is spherical, in particular spherical, in the region of the seat surface. 6. Valve design according to one of claims 1 to 4, characterized in that the valve seat ( 6 ; 26 ) is conical in the region of the seat surface, in particular as a flat truncated cone. 7. Valve design according to one of the preceding claims, characterized in that the cylindrical receptacle (bore 11 ; 39 ) adjoins the surface of the valve seat ( 6 ). 8. Valve design according to claim 7, characterized in that the valve seat ( 26 ) overlaps the cylindrical receptacle (bore 11 ) radially outward. 9. Valve design according to one of the preceding claims, characterized in that the cylindrical receptacle (bore 11 ) is integrally formed for Ven valve seat ( 6 ). 10. Valve design according to claim 9, characterized in that a valve plate ( 21 ) containing the valve seat ( 6 ) is assigned a cover plate ( 22 ) which contains the cylindrical receptacle (bore 11 ). 11. Valve configuration according to one of the preceding claims, characterized in that the channel connection (throttle bore 17, 30, throttle passage 20; recess 35; 40) by a radial connection (throttle bore 17, throttle passage 20) (for lying between sliding guide and seat area room 16 ) is formed. 12. Valve design according to claims 10 and 11, characterized in that the radial connection (throttle bore 17 ; throttle duct 20 ) is formed by at least one radial throttle duct ( 20 ) delimited by valve plate ( 21 ) and cover plate ( 22 ). 13. Valve design according to claim 12, characterized in that the radial connection (throttle bore 17 ; throttle duct 20 ) is formed by at least one radial throttle bore ( 17 ). 14. Valve design according to one of claims 1 to 10, characterized in that the channel connection (throttle bore 17 ; 20 ; throttle channel 20 ; recesses 35 ; 40 ) through an axial connection (Ausneh lines 35 ; 40 ; throttle bore 30 ) to between the sliding guide and seat lying area (room 34 ; 37 ) is formed. 15. Valve design according to claim 14, characterized in that the axial connection is formed by a throttle bore ( 30 ) radially offset from the cylindrical receptacle (bore 11 ). 16. Valve design according to claim 15, characterized in that the throttle bore ( 30 ) is provided in the cover plate ( 25 ). 17. Valve design according to claim 14, characterized in that the axial connection (recess 35 ; 40 ; throttle bore 30 ) comprises a recess ( 35 ) seen in the circumference of the cylindrical receptacle (bore 33 ). 18. Valve design according to claim 17, characterized in that the axial connection (recess 35 ; 40 ; throttle bore 30 ) is formed by recesses ( 35 ) provided in a regular arrangement in the circumference of the cylindrical receptacle (bore 33 ). 19. Valve design according to claim 14, characterized in that the axial connection (recess 35 ; 40 ; throttle bore 30 ) has a throttle point (recess 40 ) dependent on the stroke of the locking member ( 36 ) in cross section to the low pressure side. 20. Valve design according to claim 19, characterized in that the throttle point (recess 40 ) which is variable in cross section is formed by recesses ( 40 ) provided in the circumference of the cylindrical receptacle (bore 11 ; 33 ; 39 ). 21. Valve design according to claim 19 or 20, characterized in that the recesses ( 40 ) have a cross section widening in the stroke direction to the low pressure side. 22. Valve design according to claim 21, characterized in that the cross-section in the stroke direction Ausneh openings ( 40 ) from a lying in the region of the guide cross section of the cylindrical receptacle (bore 11 ; 33 ; 39 ) cross-sectional plane.