Valve assembly

Abstract

Valve assembly, in particular for damping pressure oscillations in a hydraulic system, comprising a valve housing (5) in which a longitudinal channel (6) connecting a valve inlet (9) with a valve outlet (13) is arranged, with a closing element (4) inserted in the longitudinal channel (6), which is acted upon by a closing spring (1) in the direction of a valve seat (12) formed in the valve housing (5), wherein preferably a hydraulic orifice (14) in the form of a bypass channel is arranged in parallel to the closing element (4) to bypass it, wherein an elastic friction element (3) is arranged downstream of the closing element (4) in the valve housing (5), which is frictionally engaged between the valve housing (5) and the closing element (4), characterized in that the friction element consists of an elastomeric O-ring (3) which is fixed to the closing element (4).wherein the O-ring (3) is fixed on the side of the valve housing facing away from the longitudinal channel (6) in the area of ​​the closing element (4), for this purpose the closing element (4) cooperates at least indirectly or directly with a pin (7) which is guided in the valve housing (5) on the side of the housing facing away from the longitudinal channel (6), wherein the closing element (4) has the contour of a spherical cap to which the cylindrical pin (7) is attached as a homogeneous component, wherein at a distance from the spherical cap the pin (7), which extends section by section into the closing spring (1), has a collar (17) outside the closing spring (1), on which both the closing spring (1) and the O-ring (3) are supported under preload within an annular groove (18) formed in the collar (17).

Description

[0001] The invention relates to a valve assembly, in particular for damping pressure oscillations in a hydraulic system, according to the preamble of patent claim 1.

[0002] A valve assembly of the specified type is already known from DE 10 2009 006 980 A1. This valve assembly is a component of a damper unit for minimizing the pressure pulsation initiated by a piston pump in a motor vehicle brake. The valve assembly consists of a cartridge-shaped valve housing in which a closing body, loaded by a closing spring, interacts with a valve seat in a manner dependent on the differential pressure. To vary the flow, the valve housing has a first and a second hydraulic orifice of different sizes, with the special feature that the first orifice is arranged in series and the second orifice is arranged parallel to the closing body in the valve housing. However, the proposed arrangement has the disadvantage that the closing body, when lifted off the valve seat, is prone to vibrations that generate undesirable valve noise.

[0003] Further valve assemblies are known from the documents DE 10 2011 078 250 A1, DE 197 24 511 C1, DE 100 59 317 A1, DE 10 2004 030 976 A1, US 4 531 542 A, DE 10 2009 006 890 A1, DE 195 11 455 A1 and DE 40 28 606 A1.

[0004] It is the object of the present invention to further develop a valve assembly of the type mentioned at the outset in order to avoid the aforementioned disadvantage by means of a design that is as simple and functionally improved as possible.

[0005] This object is achieved according to the invention for a valve assembly of the specified type with the characterizing features of patent claim 1.

[0006] Further features and advantages of the invention will become apparent from the following description of several embodiments with reference to drawings.

[0007] They show: Fig. 1 a first exemplary valve assembly in longitudinal section, with a friction element which is clamped in the valve inlet between the valve housing and a pin attached to the closing body, Fig. 2 a perspective view of the Fig. 1 pin shown, to which the closing body is connected as a one-piece plate valve, Fig. 3 a second exemplary valve assembly in longitudinal section, with a friction ring fixed in the longitudinal channel of the valve housing as a friction element, through which the closing body with its pin extends frictionally, Fig. 4 a perspective view of the Fig. 3, which is integrally connected to the pin tapered at its upper end, Fig. 5 a perspective view of a friction element designed as a wave spring for use as a closing spring in the valve housing, which, if desired or required, can be combined with one of the other elements shown in the Fig. 1-4, 6-11 shown friction elements can be structurally combined, Fig. 6 shows a further exemplary valve assembly in longitudinal section, with an O-ring fixed to a pin downstream of the closing body, which acts as a friction element and frictionally engages the inner wall of the valve housing, wherein the closing body is designed as a ball valve which contacts the upper head end of the pin as a separate component, Fig. 7 deviating from Fig. 6 the closing body is designed as a plate valve, which is connected in one piece to the pin, Fig. 8 deviating from Fig. 6 an arrangement of the O-ring directly between the spherical closing body and the pin, Fig. 9 the object after Fig. 8 supplemented by a similar O-ring, which is arranged in an annular groove of the pin for the purpose of frictional engagement in the valve housing, Fig. 10 deviating from the subject matter Fig. 7 a spherical closing body formed integrally on the pin, Fig. 11 deviating from the subject matter Fig. 6 the spherical closing body, which is fixed by means of a press fit in a recess at the head end of the pin.

[0008] Before discussing the differences between the Fig. 1 to 11 shown valve assemblies are discussed, should first be based on the Fig. 1 the common features of all valve assemblies are explained.

[0009] The Fig. 1, like the other figures, shows a longitudinal section through a detailed overall view of the basic design of the exemplary valve assembly, which is preferably used to dampen pressure oscillations in a brake hydraulic system of a motor vehicle. For this purpose, a hydraulic orifice 14 in the form of an orifice notch is arranged in the valve seat 12, which is formed at the lower end of a longitudinal channel 6 penetrating vertically through the valve housing 5, so that, regardless of the position of the closing body 4, a permanent connection from the valve inlet 9 in the direction of the valve outlet 13 is created in the valve assembly as a result of the orifice 14. The closing body 4, which interacts with the valve seat 12, is acted upon by a closing spring 1, which holds the closing body 4 in its basic position on the valve seat 12, so that in the basic position only the cross-section of the orifice 14 is exposed.The closing body 4 is therefore lifted off from the valve seat 12 solely as a function of the differential pressure, i.e. if the hydraulic pressure acting on the closing body 4 in the valve inlet 9 is greater than the spring pressure of the closing spring 1, which is exemplified as a cylindrical spring. The closing spring 1 is supported with its first coil end on the closing body 4 and with its second coil end, which is arranged diametrically opposite the first coil end, on the lower horizontal end of the valve housing 5.

[0010] The valve housing 5 is two-part, consisting of an upper housing part and a lower housing part, which are both connected to one another at least positively, preferably non-positively. The upper housing part consists of a thick-walled blank made of free-cutting steel, preferably by cold forming or contour turning, on the underside of which the valve seat 12 is formed. In contrast, the closing body 4, together with the closing spring 1, is accommodated in the lower housing part, which is cup-shaped and formed from a deep-drawn sheet. Furthermore, the cup-shaped lower housing part has at least one outlet opening in its outer surface and / or in its cup base to form the valve outlet 13, which outlet opening is preferably produced by stamping.

[0011] In order to minimize the noise emission of the closing body 4 by suitable damping of its vibration behavior, the invention proposes that an elastic friction element 1, 2, 3 is arranged either upstream or downstream of the closing body 4 in the valve housing 5, which is frictionally received between the valve housing 5 and the closing body 4.

[0012] In the embodiments according to the Fig. 1-4, 7, the closing body 4 is designed as a plate valve, which interacts with a valve seat 12 designed as a flat sealing seat. Alternatively, the Fig. 6, 8-11 each have a closing body 4 which is designed as a ball valve or at least spherical, for which purpose the closing body 4 interacts with a valve seat 12 which is shown as an inclined shoulder seat.

[0013] A special feature of the invention is shown in the embodiment according to Fig. 5, according to which the friction element is formed directly by the closing spring 1 arranged between the valve housing 5 and the closing body 4, the individual windings of which are made of spring steel and are in frictional contact with each other in sections. The closing spring 1 therefore consists either of several stacked disc springs or, according to the Fig. 5 from a preferably sinusoidally loaded corrugated ring spring wound from strip spring steel.

[0014] According to a further advantageous embodiment according to the Fig. 3 and Fig. 4, the friction element consists of a friction ring 2 fixed in the longitudinal channel 6, through which a pin 7 connected to the closing body 4 protrudes, which at least partially contacts the friction ring 2 with its outer surface in a frictionally engaged manner. The friction ring 2, preferably made of spring steel, is clamped off-center within a housing groove 15 to ensure unobstructed flow, with the pin 7 being provided with a plurality of flattened portions 8 on its circumference to ensure unobstructed flow through the longitudinal channel 6.

[0015] According to the Fig. 1, 6 to 11, the friction element consists of an elastomeric O-ring 3, which is fixed either in the valve housing 5 or at least directly or indirectly on the closing body 4.

[0016] In detail, the Fig. 1, Fig. 2, the O-ring 3 is fixed upstream of the closing body 4 in the valve inlet 9 of the valve housing 5. The O-ring 3 is frictionally penetrated by a pin 7 connected to the closing body 4, which extends from the direction of the valve inlet 9 into the longitudinal channel 6. The pin 7 is provided with a blind bore and an adjoining transverse bore 10, 11 for the unhindered passage of the pressure medium in the longitudinal channel 6, wherein the pin 7 further has several flattened portions 8 on its outer surface for unhindered flow through the longitudinal channel 6 in the outlet area of ​​the transverse bore 11, which in the perspective view according to Fig. 2 are clearly visible.

[0017] According to the examples of implementation according to the Fig. 6 to 11, the O-ring 3 is fixed in the region of the closing body 4 on the side facing away from the longitudinal channel 6, for which purpose the closing body 4 is at least directly or indirectly connected to a pin 7 which is guided in the lower part of the valve housing 5 on the side facing away from the longitudinal channel 6. The pin 7 projects with its lower end into the closing spring 1 and has, at its upper end facing away from the closing spring 1, the closing body 4 directed towards the valve seat 12.

[0018] For precise mounting of the O-ring 3, the pin 7 points into the Fig. 6, Fig. 7, Fig. 9, Fig. 10 has an annular groove 18 at its end facing the closing body 4, so that only the area of ​​the O-ring 3 projecting radially from the annular groove 18 makes frictional contact with the valve housing 5 downstream of the valve outlet 13.

[0019] Deviating from this is the Fig. 8 the O-ring 3 is clamped between the spherical closing body 4 and the pin 7 in the lower part of the valve housing 5, the diameter of which is approximately adapted to the O-ring 3, so that the O-ring 3 cushions the closing body 4 in a damped manner and centers it without wobbling.

[0020] In addition to the description of the Fig. The embodiment shown in Figure 8 shows the Fig. 9, a further O-ring 3 is inserted within an annular groove 18 of the pin 7, so that due to the redundant arrangement of the O-ring 3, improved vibration damping is achieved, since the design of Fig. 8 going beyond Fig. 9 the further O-ring 3 frictionally contacts the inner wall of the housing base.

[0021] In the embodiment according to Fig. 10, the closing body 4 has the contour of a spherical cap, to which the cylindrical pin 7 adjoins as a homogeneous component. At a distance from the spherical cap, the pin 7, which extends partially into the closing spring 1, has the collar 17 outside the closing spring 1, on which both the closing spring 1 and the O-ring 3 are supported under preload within the annular groove 18 formed in the collar 17. The collar 17 thus advantageously enables the vibration-damping friction function of the O-ring 3 and the closing function of the closing spring 1 in a simple manner, in a dual function. Furthermore, the pin 7 extending below the collar 17 into the closing spring 1 prevents the cylindrically wound closing spring 1 from buckling.

[0022] With regard to a particularly advantageous reception of the spherical closing body 4 on the pin 7, reference is made to the Fig.11, according to which the closing body 4 is held by means of a press fit within a recess 16 of the head-shaped pin end. Thus, a cost-effective yet high-quality, hardened ball can be used as the closing body 4, which is pressed into the easily manufactured pin 7. List of reference symbols 1 closing spring 2 friction ring 3 O-ring 4 locking bodies 5 valve housing 6 Longitudinal channel 7 cones 8 Flattening 9 Valve inlet 10 blind bore 11 Cross hole 12 Valve seat 13 Valve outlet 14 aperture 15 Housing groove 16 Deepening 17 Bund 18 ring groove

Claims

[1] Valve assembly, in particular for damping pressure oscillations in a hydraulic system, comprising a valve housing (5) in which a longitudinal channel (6) connecting a valve inlet (9) to a valve outlet (13) is arranged, with a closing body (4) inserted in the longitudinal channel (6) which is acted upon by a closing spring (1) in the direction of a valve seat (12) formed in the valve housing (5), wherein a hydraulic orifice (14) in the form of a bypass channel is preferably arranged in parallel to the closing body (4) to bypass the closing body (4), wherein an elastic friction element (3) is arranged downstream of the closing body (4) in the valve housing (5) and is frictionally received between the valve housing (5) and the closing body (4), characterized by, in which the friction element consists of an elastomeric O-ring (3) which is fixed to the closing body (4), wherein the O-ring (3) is fixed on the valve housing side facing away from the longitudinal channel (6) in the region of the closing body (4), for which purpose the closing body (4) interacts at least directly or indirectly with a pin (7) which is guided in the valve housing (5) on the housing side facing away from the longitudinal channel (6), wherein the closing body (4) has the contour of a spherical cap to which the cylindrical pin (7) is connected as a homogeneous component, wherein at a distance from the spherical cap the pin (7), which extends in sections into the closing spring (1), has a collar (17) outside the closing spring (1), on which collar both the closing spring (1) and the O-ring (3) are supported under prestress within an annular groove (18) formed in the collar (17).

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