Conical pressure control valve

Abstract

The present invention relates to a pressure control valve (51) for controlling a fluid pressure, in particular for ventilating the crankcase of an internal combustion engine of a motor vehicle, the pressure control valve comprising: a valve housing (53) having a fluid inlet (55), a fluid outlet (59) and a valve seat (63); a valve member (65) having an in particular conically tapered closing element (67), the valve member (65) being movable between a closed position, in which the closing element (67) is in sealing contact with the valve seat (63) in order to close the fluid outlet (59), and an open position, in which the closing element releases the valve seat (63) and opens the fluid outlet (59); a diaphragm (69), in particular a convoluted diaphragm, for actuating the valve member; and a shielding device (71), such as a shielding plate, for shielding the diaphragm (69) from the fluid; the valve member (65) extending through the shielding device (71) without contact and guidance.

Description

[0001] Woco Industrietechnik GmbH,

[0002] Hanauer Landstraße 16, 63628 Bad-Soden-Salmünster

[0003] Conical pressure control valve

[0004] The present invention relates to a pressure control valve for regulating a fluid pressure, in particular for crankcase ventilation of an internal combustion engine of a motor vehicle. Furthermore, the present invention relates to a crankcase ventilation system with a pressure control valve of this type.

[0005] Pressure control valves of this type are used, for example, in the ventilation line between the crankcase and intake manifold or the air filter of an internal combustion engine in motor vehicles. The aim is to prevent the pressure or negative pressure in the container being vented from rising above a predetermined value. This is achieved by the pressure control valve installed in the ventilation line between the intake manifold and the crankcase of the internal combustion engine, which draws through so-called blow-by gas. During operation of the internal combustion engine, a slight negative pressure should always prevail in the crankcase to prevent oil-containing blow-by gases from escaping through the seals, for example, and polluting the environment. On the other hand, the specified negative pressure should not be significantly undercut, as otherwise leaks would suck unwanted air into the crankcase.

[0006] The basic task of these known pressure control valves is to throttle the high negative pressure in the overrun or part-load range of -800 mbar when the throttle valve is closed in order to prevent damage to components. Generic pressure control valves, such as those known from DE 102013019885 B4, use diaphragms to actuate a valve element that regulates the fluid. One problem with diaphragm-actuated pressure control valves is that the diaphragm is exposed to the blow-by gas and is attacked by it, leading to wear. According to DE 102013019885 B4, this problem can be solved by inserting a separating base and moving the diaphragm further upwards so that it is no longer directly exposed to the aggressive blow-by gas.However, the control quality of the pressure control valve according to DE 102013019885 B4 has proven to be fundamentally disadvantageous. This is impaired by the fact that, due to the large stroke, i.e., the vertical distance between the diaphragm and the seal-seat-side guide position of the valve member, tilting relative to the actuating direction of the valve member can occur during the actuating movement, which leads to the flow cross-section not being able to be adjusted reliably enough. DE 10201309885 B4 counteracts this phenomenon by providing a narrow passage opening for the valve member tappet in the separating plate and by guiding the valve member tappet during its actuating movement.

[0007] However, due to the large actuating stroke of the pressure control valves according to DE 102013019885 B4, achieving reliable control quality is still only possible with great effort. Furthermore, the tight guidance of the valve element during the actuating movement results in high manufacturing and assembly costs, and the guidance also has a detrimental effect on the wear of the pressure control valve. Furthermore, the tight guidance can cause the tappet to freeze or stick to the guide due to moisture and cold temperatures. A further disadvantage of the pressure control valve according to DE 10201390885 B4 is that the valve element tends to stick to the valve seat, disrupting pressure control due to the very low diaphragm diameter to valve seat diameter ratio.

[0008] An object of the present invention is to overcome the disadvantages of the prior art, in particular to provide a more compact pressure control valve with improved control quality and / or reduced risk of suction and freezing.

[0009] This problem is solved by the features of the independent claims.

[0010] According to a first aspect of the present invention, a pressure control valve is provided for regulating fluid pressure, in particular for crankcase ventilation of an internal combustion engine of a motor vehicle. The pressure control valve can be installed in a ventilation line between the crankcase and the intake manifold or air filter of the internal combustion engine. It serves, in particular, to prevent the pressure or negative pressure in the container to be vented from rising above a predetermined value, in order to ensure that a low negative pressure always prevails in the crankcase. The pressure control valve is designed to throttle the high negative pressure in the overrun or partial load range of -800 mbar when the throttle valve is closed, in order to prevent damage to mechanical components.

[0011] The pressure control valve comprises a valve housing with a fluid inlet, a fluid outlet, and a valve seat. The pressure control valve can determine a flow direction of the fluid through the valve housing. The valve seat can be located between the fluid inlet and the fluid outlet, viewed in the flow direction. For example, the pressure control valve has exactly one fluid outlet and exactly one valve seat associated with the fluid outlet.

[0012] The pressure regulating valve according to the invention further comprises a valve member with a closing element that tapers in particular conically, convexly or concavely. In particular, the closing element tapers in the direction of the valve seat. The valve member can be moved between a closed position, in which the closing element comes into sealing contact with the valve seat in order to close off the fluid outlet, and an open position, in which it releases the valve seat and opens the fluid outlet. The pressure is therefore regulated via the valve member by either permitting fluid flow through the pressure regulating valve, in particular the housing, and if so, to what extent, or by preventing the fluid flow. The inventors have discovered that by using a closing element that tapers in particular conically, regardless of any tilting of the valve member, i.e. in the event of misorientation orMisalignment with respect to its actuating and / or movement direction enables reliable pressure control and thus reliably ensures the functionality of the pressure control valve. The valve element can be a globe valve and / or the valve element can be designed to perform an axial actuating movement between the open and closed positions.

[0013] Furthermore, the pressure control valve according to the invention comprises a diaphragm, in particular a beaded diaphragm, for actuating the valve member. When used in generic pressure control valves, a beaded diaphragm has the disadvantage, compared to a rolling diaphragm, of a poorer ratio of rigid support surface to movable section, which causes the movement of the valve member with which the diaphragm is in force-transmitting contact, in particular is attached thereto. This is because the same degree of misalignment of the valve member when using a rolling diaphragm has a less pronounced effect on the resulting tilting of the valve member relative to the ideal position and / or relative to the actuating direction. However, it has been found that for the intended use of the present pressure control valve according to the invention, a beaded diaphragm is advantageous due to its advantages, particularly with regard to clamping and its attachment to the valve member.

[0014] The pressure control valve further comprises a shielding device, such as a shielding plate, for shielding the diaphragm from the fluid. It has been found that, particularly when the pressure control valve was used for crankcase ventilation, the diaphragm in the prior art was clogged with blow-by gas, leading to its damage. In this respect, the diaphragm can be protected by the shielding device, so that it retains its functionality for longer. It should be understood that small amounts of fluid creeping towards the diaphragm can certainly occur, but the shielding device is arranged with respect to the diaphragm in such a way that the diaphragm is not directly or immediately impacted by the incoming fluid flow.

[0015] According to the first aspect of the present invention, the valve member extends through the shielding device without contact or guides. This makes it easier to manufacture and assemble the pressure control valve. Furthermore, the risk of the valve member freezing or sticking to a possible guide in the shielding device due to moisture and cold temperatures is eliminated. This also results in higher tolerances during manufacturing and assembly, which in turn has a positive effect on manufacturing and production costs.In an exemplary embodiment of the pressure control valve according to the invention, the shielding device has a through-opening for the valve member, in particular the closing element, and a particularly circumferential gap between the shielding device and the valve member amounts to at least 10%, in particular at least 20% or at least 30%, of a movement amplitude of the valve member between the open and closed positions. In other words, when displacing between the open and closed positions, the valve member can penetrate through the shielding device or at least move axially translationally relative to it, wherein a distance transverse to the direction of movement of the valve member exists between the latter and the shielding device. This distance can be uniformly designed all the way around and is dimensioned large enough to prevent, in particular, the risk of the valve member freezing to the shielding device.

[0016] According to a further exemplary embodiment of the pressure control valve according to the invention, the shielding device has a through-opening for the valve member, in particular the closing element, whose cross-sectional area is at least as large as an inner cross-sectional area of ​​the valve seat. For example, the cross-sectional area of ​​the through-opening is at least 30%, 50%, 70%, or at least 90% larger than the inner cross-sectional area of ​​the valve seat.

[0017] According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, a pressure control valve is provided for regulating a fluid pressure, in particular for crankcase ventilation of an internal combustion engine of a motor vehicle. The pressure control valve can be installed in a ventilation line between the crankcase and the intake manifold or air filter of the internal combustion engine. It serves, in particular, to prevent the pressure or negative pressure in the container to be vented from rising above a predetermined value in order to ensure that a low negative pressure always prevails in the crankcase. The pressure control valve is designed such that it can throttle the high negative pressure in the overrun or partial load range of -800 mbar when the throttle valve is closed in order to avoid damage to mechanical components.The pressure control valve comprises a valve housing with a fluid inlet, a fluid outlet, and a valve seat. The pressure control valve can determine a flow direction of the fluid through the valve housing. The valve seat can be located between the fluid inlet and the fluid outlet, viewed in the flow direction. For example, the pressure control valve has exactly one fluid outlet and exactly one valve seat associated with the fluid outlet.

[0018] The pressure regulating valve according to the invention further comprises a valve member with a closing element that tapers in particular conically, convexly or concavely. In particular, the closing element tapers in the direction of the valve seat. The valve member can be moved between a closed position, in which the closing element comes into sealing contact with the valve seat in order to close off the fluid outlet, and an open position, in which it releases the valve seat and opens the fluid outlet. The pressure is therefore regulated via the valve member by either permitting fluid flow through the pressure regulating valve, in particular the housing, and if so, to what extent, or by preventing the fluid flow. The inventors have discovered that by using a closing element that tapers in particular conically, regardless of any tilting of the valve member, i.e. in the event of misorientation orMisalignment with respect to its actuating and / or movement direction enables reliable pressure control and thus reliably ensures the functionality of the pressure control valve. The valve element can be a globe valve and / or the valve element can be designed to perform an axial actuating movement between the open and closed positions.

[0019] Furthermore, the pressure control valve according to the invention comprises a diaphragm, in particular a beaded diaphragm, for actuating the valve member. When used in generic pressure control valves, a beaded diaphragm has the disadvantage, compared to a rolling diaphragm, of a poorer ratio of rigid support surface to movable section, which causes the movement of the valve member with which the diaphragm is in force-transmitting contact, in particular is attached thereto. This is because the same degree of misalignment of the valve member when using a rolling diaphragm has a less pronounced effect on the resulting tilting of the valve member relative to the ideal position and / or relative to the actuating direction. However, it has been found that for the intended use of the present pressure control valve according to the invention, a beaded diaphragm is advantageous due to its advantages, particularly with regard to clamping and its attachment to the valve member.The membrane is essentially shielded from the fluid. It should be understood that fluid can certainly flow toward the membrane, but the membrane is arranged or shielded with respect to the fluid flow in such a way that direct, immediate flow is prevented. For example, the membrane can be shielded by a shielding device as described above.

[0020] According to a further aspect of the present invention, the ratio of the maximum outer dimension of the diaphragm to the minimum inner dimension of the valve seat is at least 3.5. For example, this is a diaphragm outer diameter and / or the dimension of the diaphragm according to which it is attached to the valve housing. The inner dimension of the valve seat defines the free flow cross-section when the valve member is in the open position. The inventors of the present invention have discovered that the ratio of the diaphragm outer dimension to the valve seat inner dimension is crucial for preventing the valve member from sticking to the valve seat. It has been discovered that if the diaphragm outer / valve seat inner dimension ratio is too small, there is a risk that the diaphragm will stick to the valve seat, which impairs pressure regulation or no longer ensures the functionality of the pressure control valve.

[0021] According to an exemplary embodiment of the pressure control valve according to the invention, the ratio is at least 4, 4.5 or at least 5 and / or at most 10, in particular at most 9, 8 or at most 7. The inventors were able to find that in the said range, the tendency towards suction can be reliably avoided, whereby a compact pressure control valve can be produced.

[0022] According to a further exemplary embodiment of the present invention, the valve member can be displaced without guidance, in particular relative to the shielding device, in such a way that a tilting relative to the adjustment direction, which defines a particular axial direction of movement of the valve member, in particular of up to 10° is permitted. For example, in the open position, a crescent-shaped gap is formed between the valve member and the valve seat in the event of tilting. According to an exemplary development of the present invention, the crescent-shaped gap in the event of tilting of the valve member essentially corresponds to the annular gap between the valve member and the shielding device that would occur in a normal operating state if the valve member were not tilted or were optimally aligned with regard to the adjustment direction and / or the valve seat.Thus, in the pressure control valve according to the invention, even if the valve member is not optimally aligned, the control function of the pressure control valve is maintained and the control quality is not impaired.

[0023] In a further exemplary embodiment of the pressure control valve according to the invention, the valve member is preloaded, in particular spring-loaded, toward the open position. In other words, a preload component can be provided that urges the valve member toward the open position. For example, the preload force can be directed counter to the diaphragm actuating force. In other words, the diaphragm actuating force can be oriented toward the closed position of the valve member, i.e., toward the valve member.

[0024] According to a further exemplary embodiment of the present invention, the movement amplitude, in particular the stroke, of the valve member during the axial and / or translational control of the fluid pressure is at most 5 mm, in particular at most 4 mm, 3 mm, or at most 2 mm, 1.5 mm, 1 mm, or 0.5 mm. For example, the inventors have discovered that the main pressure control can be covered within an extremely narrow movement amplitude spectrum. Especially at low volume flows, the opening stroke can even be at most 0.5 mm or less.

[0025] According to a further exemplary embodiment of the pressure control valve according to the invention, the valve member, in particular the closing element, comprises an elastic material, in particular an elastomer material such as fluoroelastomer (FKM), for example fluorosilicone (FVMQ), particularly on its closing surface cooperating with the valve seat. In particular, the valve member is coated therewith. The elastic material also reduces the tendency for sticking. Furthermore, noise development caused by the contact between the valve member and the valve seat can be reduced, in particular prevented.

[0026] In a further exemplary embodiment of the pressure control valve according to the invention, the elastic material is provided, in particular coated, with a friction-reducing coating or layer. For example, the friction-reducing coating is a thermoplastic and / or based on a fluorocarbon compound, such as PTFE. The coating or layer can also be a lubricating varnish, for example. In general, the friction-reducing coating or layer counteracts wear on the elastic material. A friction-reducing coating or layer means that the static friction is reduced compared to the static friction value of the elastic material.

[0027] Preferred embodiments are specified in the subclaims.

[0028] In the following, further properties, features and advantages of the invention will become clear by describing preferred embodiments of the invention with reference to the accompanying exemplary drawings, in which:

[0029] Figure 1 is a schematic diagram of an exemplary installation location of an exemplary embodiment of a pressure control valve according to the invention;

[0030] Figure 2 is a sectional view of an exemplary embodiment of a pressure control valve in an open position;

[0031] Figure 3 shows the pressure control valve from Figure 2 in a closed position;

[0032] Figure 4 is a schematic diagram of a section of a

[0033] pressure control valve;

[0034] Figure 5 is a bottom view of the pressure control valve according to Figure 4;

[0035] Figure 6 shows another exemplary schematic diagram of a

[0036] pressure control valve in an open position; and

[0037] Figure 7 is a bottom view of the pressure control valve from Figure 6. In the following description of exemplary embodiments of the present invention, a pressure control valve for regulating a fluid pressure is generally designated by reference numeral 51. For example, this is used for crankcase ventilation of an internal combustion engine of a motor vehicle.

[0038] Figure 1 shows a schematic view of a crankcase ventilation system of an internal combustion engine, which is designated below with the reference numeral 29. The crankcase ventilation system 29 comprises a crankcase 15 with a flow outlet opening 25 through which blow-by gas can escape from the crankcase 15, and a pressure control valve 51 according to the invention, which is fluidly connected to the flow outlet opening 25 and is schematically indicated in Figure 1. As can be seen in Figure 1, the fluid connection between the pressure control valve 51 and the flow outlet opening 25 can be realized via a pipe system, such as an outlet line 135, which fluidly connects the flow outlet opening 25 of the crankcase to a flow passage opening 27 toward the pressure control valve 51.Alternatively, the pressure control valve 51 can be mounted on the crankcase 15 (not shown) in such a way that the flow passage opening 27 belongs to the separation device 51.

[0039] Furthermore, Figure 1 shows an example of the generation of blow-by gas and the general installation position of a pressure control valve 51 according to the invention. It depicts an internal combustion engine 1 that is fluidly coupled to a fresh air supply 3, an exhaust gas discharge 5, and a crankcase ventilation 7. The internal combustion engine 1 comprises a cylinder head cover 9, a cylinder head 11, a cylinder 13, and a crankcase 15. A piston 17 is guided within the cylinder, which defines a displacement 19 from a crankcase interior 21. Sealing rings (not shown) are provided between the piston 17 and the cylinder 13 to seal the displacement 19 from the crankcase interior 21. Nevertheless, combustion gases and / or unburned gases flow between the piston 17 and the cylinder 13 from the displacement 19 into the spherical housing interior 21.The resulting gas stream 23 is also referred to as a blow-by gas stream and, in addition to air and oil, also includes combustion gases and unburned fuel components. To prevent a pressure increase in the crankcase 15, the gas stream 23 is discharged from the crankcase 15 via a crankcase ventilation system 7 and fed to the fresh air supply 3. The crankcase ventilation system 7 comprises, in particular, the fluidic coupling of the flow outlet opening 25 of the crankcase 15 to the pressure control valve 51. The pressure control valve 29 is further fluidically connected to the crankcase 15 via a return line 31 for the return flow of separated particles, such as oil. In particular, the return line 31 fluidically connects a return outlet 33 of the separation device 29 to a return inlet 35 on the crankcase 15.Upstream of the crankcase ventilation 7, a return line 37 fluidly connects the pressure control valve 51 to the fresh air supply 3 in order to supply the fresh air supply 3 with a gas flow cleaned of particles, such as oil. The resulting fresh air flow 41 is compressed by a compressor wheel 39 and fed via a charge air cooler 43 to the internal combustion engine 1 via the cylinder head 11. Combustion gases that do not reach the crankcase 15 between the piston 17 and the cylinder 13 are fed as exhaust gas 45 via an exhaust gas discharge to a turbocharger 47, which drives the compressor wheel 39 in the fresh air supply 3 via a shaft 49.

[0040] It should be understood that the installation position of the pressure control valve 51 according to the invention, when used as an oil separator in an internal combustion engine, is not limited to the installation position shown in Figure 1, nor to use in a crankcase ventilation system 29. For example, the pressure control valve 51 can also be used to separate particles from gas streams that escape from the internal combustion engine 1 between the cylinder 13 and the cylinder head 11 and / or between the cylinder head 11 and the cylinder head cover 9. Another possible area of ​​application is in the fresh air supply 3 and / or in the exhaust gas discharge 5, which can be fluidly coupled to one another, in particular via the shaft 49 connecting the compressor wheel 39 and the turbine wheel 47.

[0041] Figures 2 and 3 show an exemplary embodiment of a pressure control valve 51 according to the invention in different operating positions, namely in the open position according to Figure 2 and in the closed position according to Figure 3. The pressure control valve 51 according to the invention essentially comprises the following main components: a valve housing 53 with a fluid inlet 55, at which a fluid flow with a certain fluid pressure can enter (reference numeral 57), a fluid outlet 59, at which a fluid flow with a certain fluid pressure can exit the valve housing 53 (reference numeral 61) and a valve seat 63 arranged in the flow direction between the fluid inlet 55 and the fluid outlet 59;a valve member 65 with, for example, a conically tapered closing element 67, which is displaceable between the open position shown in Figure 2, in which it releases the valve seat 63 and opens the fluid outlet 59, and a closed position shown in Figure 3, in which it assumes sealing contact with the valve seat 63 to close the fluid outlet 59; a membrane 69, which is designed, for example, as a beaded membrane, for actuating the valve member 65; and a shielding device 71 designed as a plate for shielding the membrane 69 from the fluid 57.

[0042] The valve housing 53 can further comprise a valve housing base 73 and a valve cover 75. The beaded membrane is connected to the valve housing 53 laterally, in particular circumferentially, at the level of the latter, in particular clamped between the valve housing base 77 and the valve cover 75, and rests flat in sections on a base 79 connected to the closing element 67. As can also be seen in Figures 1, 2 and 3, the pressure control valve 51 comprises a spring 81 for preloading the valve member 65 into the open position shown in Figure 2. During a closing process of the valve member 65, the spring 81 therefore creates a resistance force that dampens the movement of the valve member 65 and thus ensures that damage caused by a hard impact of the valve member 65 on the valve seat 63 can be avoided.

[0043] During operation of the pressure control valve 51, the acting force ratio is such that the spring 81 urges the valve member 65 into the open position, while the diaphragm 69, exposed from above to pressure, for example in the crankcase, exerts a downward force on the valve member 65 toward the closed position. In the closed state according to Figure 3, a suction force directed downwards further toward the closed position also acts, for example from an intake tract of the internal combustion engine arranged downstream of the pressure control valve 51.

[0044] Referring again to Figures 2 and 3, preferred dimensional relationships of the pressure control valve 51 according to the invention are apparent. An essential aspect of the pressure control valve 51 is that the valve member 65 extends contact-free and guide-free through the shielding plate 71 during its translational axial adjustment movement between the open and closed positions. The shielding plate 71 defines a through-opening 83 for the valve member 65, which is dimensioned with respect to an outer dimension of the valve member 65 such that a particularly circumferential gap s remains between the shielding plate 71 and the valve member 65. Furthermore, a cross-sectional area of ​​the through-opening in the exemplary embodiment according to Figures 2 and 3 is significantly larger than an inner cross-sectional area a of a fluid passage opening 85 delimited by the valve seat 63.Furthermore, it is apparent from the embodiment according to Figures 2 and 3 that a maximum outer dimension b of the bead membrane 69 is significantly larger than the minimum inner dimension of the valve seat 63, which is defined by the fluid passage cross-section a.

[0045] Referring to Figures 4-7, further aspects and advantages of the present invention become clear. Figures 4 and 5 show a section and a bottom view of an exemplary embodiment of a pressure control valve 51 according to the invention in an open position with a very small stroke of the valve member 65 of at most 5 mm. Figures 4 and 5 illustrate a normal operating state of the pressure control valve 51, in which, in the open position, a circumferential annular gap 87 results between the closing element 67 and the valve seat 63 in order to ensure fluid flow through the valve seat 63. Figures 6 and 7 schematically illustrate an operating situation of the pressure control valve 51 in which the valve member 65 is tilted by an angle α with respect to the axial actuating or movement direction A.From the schematic bottom view according to Figure 7 it can be seen that instead of the annular gap 87 present in Figure 5 in the normal operating state, a sickle-shaped gap 89 results between the closing element 67 and the valve seat 63 with the same axial adjustment direction, ie the same opening movement of the valve member 65.

[0046] A significant advantage of the pressure control valve 51 according to the invention is, as can be seen in particular from a comparison of Figures 5 and 7, that even if the valve member 65 is tilted with respect to its axial adjustment direction A, the control functions, in particular the control quality, are maintained, since with the same stroke, essentially the same opening cross-sectional area, indicated by the annular gap 87 and the crescent-shaped gap 89, results.

[0047] The features disclosed in the above description, the figures and the claims may be important both individually and in any combination for the realization of the invention in the various embodiments.

[0048] List of reference symbols

[0049] 1 combustion engine

[0050] 3 Fresh air supply

[0051] 5 Exhaust gas removal

[0052] 7 Crankcase ventilation

[0053] 9 Cylinder head cover n Cylinder head

[0054] 13 cylinders

[0055] 15 Crankcase

[0056] 17 pistons

[0057] 19 displacement

[0058] 21 Crankcase interior

[0059] 23 Gas flow

[0060] 25 Flow outlet opening

[0061] 27 Flow passage opening

[0062] 29 Crankcase ventilation system

[0063] 31 Return line

[0064] 33 Return outlet

[0065] 35 Return inlet

[0066] 37 Return line

[0067] 39 Compressor wheel

[0068] 41 Fresh air flow

[0069] 43 intercooler

[0070] 45 exhaust

[0071] 47 turbochargers

[0072] 49 Wave

[0073] 51 Pressure control valve

[0074] 53 valve housing

[0075] 55 Fluid inlet

[0076] 57 inflowing fluid

[0077] 59 Fluid leak

[0078] 61 escaping fluid

[0079] 63 Valve seat 65 Valve element 67 Closing element 69 Diaphragm 71 Shielding device

[0080] 73 Valve housing base

[0081] 75 valve cover

[0082] 77 Valve housing base

[0083] 79 Valve element base 81 Preload component

[0084] 83 through-opening 85 fluid passage 87 annular gap 89 sickle-shaped gap

[0085] A axial adjustment direction a opening cross-section s gap b outer dimension of the diaphragm

Claims

PATENT CLAIMS 1. A pressure control valve (51) for regulating a fluid pressure, in particular for crankcase ventilation of an internal combustion engine of a motor vehicle, comprising: a valve housing (53) with a fluid inlet (55), a fluid outlet (59), and a valve seat (63); a valve member (65) with a closing element (67), in particular a conically tapered one, wherein the valve member (65) is displaceable between a closed position, in which the closing element (67) makes sealing contact with the valve seat (63) to close the fluid outlet (59), and an open position, in which it releases the valve seat (63) and opens the fluid outlet (59); a membrane (69), in particular a beaded membrane, for actuating the valve member; and a shielding device (71), such as a shielding plate, for shielding the membrane (69) from the fluid; characterized in that the valve member (65) extends through the shielding device (71) without contact and guidance.

2. Pressure control valve (51) according to claim 1, characterized in that the shielding device (71) has a through-opening for the valve member, in particular the closing element (67), and a particularly circumferential gap between the shielding device (71) and the valve member (65) amounts to at least 10%, in particular at least 20% or at least 30%, of a movement amplitude of the valve member between the open and closed positions.

3. Pressure control valve (51) according to one of the preceding claims, characterized in that the shielding device (71) has a through-opening for the valve member, in particular the closing element (67), whose cross-sectional area is at least as large as an inner cross-sectional area of ​​the valve seat (63), in particular at least 30%, 50%, 70% or at least 90% larger than the inner cross-sectional area of ​​the valve seat (63). 4- Pressure control valve (51), in particular according to one of the preceding claims, for regulating a fluid pressure, in particular for crankcase ventilation of an internal combustion engine of a motor vehicle, comprising: a valve housing (53) with a fluid inlet (55), a fluid outlet (59), and a valve seat (63); a valve member (65) with a closing element (67), in particular a conically tapered element, wherein the valve member (65) is displaceable between a closed position, in which the closing element (67) makes sealing contact with the valve seat (63) to close the fluid outlet (59), and an open position, in which it releases the valve seat (63) and opens the fluid outlet (59); and a membrane (69), in particular a beaded membrane, for actuating the valve member, which membrane is substantially shielded from the fluid;characterized in that the ratio of the maximum outer dimension of the diaphragm (69) to the minimum inner dimension of the valve seat (63) is at least 3.5; 5. Pressure control valve (51) according to claim 4, characterized in that the ratio is at least 4, 4.5 or at least 5 and / or at most 10, in particular at most 9, 8 or at most 7.

6. Pressure control valve (51) according to one of the preceding claims, characterized in that the valve member (65) is displaceable without a guide in such a way that a tilting relative to the direction of adjustment, in particular of up to 10°, is permitted, wherein in particular in the open position a sickle-shaped annular gap is formed between the valve member (65) and the valve seat (63).

7. Pressure control valve (51) according to one of the preceding claims, characterized in that the valve member (65) is prestressed, in particular spring-prestressed, in the direction of the opening position, wherein in particular the prestressing force is directed counter to the diaphragm actuating force.

8. Pressure control valve (51) according to one of the preceding claims, characterized in that the movement amplitude of the valve member when regulating the fluid pressure is at most 5 mm, in particular at most 4 mm, 3 mm or at most 2 mm, 1.5 mm, 1 mm or 0.5 mm. - Pressure control valve (51) according to one of the preceding claims, characterized in that the valve member, in particular the closing element (67), in particular on its closing surface cooperating with the valve seat (63), has an elastic material, in particular an elastomer material, such as fluoroelastomer (FKM), for example fluorosilicone (FVMQ), in particular is coated therewith. . Pressure control valve (51) according to claim 9, characterized in that the elastic material is provided with a friction-reducing coating or layer, in particular is coated, wherein in particular the friction-reducing coating is a thermoplastic and / or is applied to a Fluorocarbon compound based, such as PTFE.

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