WO2021213682A1

WO2021213682A1 - Blow-off valve

Info

Publication number: WO2021213682A1
Application number: PCT/EP2020/061533
Authority: WO
Inventors: Martin Lenk; Michael Thiery; Juri Wagner; Tanner CAVDAR
Original assignee: Pierburg Gmbh
Priority date: 2020-04-24
Filing date: 2020-04-24
Publication date: 2021-10-28
Also published as: DE112020007137A5

Abstract

The invention relates to a blow-off valve having a flow housing (34) with a flow channel (36) between an inlet (38) and an outlet (40), a valve seat (42) formed between the inlet and the outlet, an actuator (10), an actuating member (28) which can be moved in translation by means of the actuator, and a control element (32) which is fastened to the actuating member and has a radially outer circumferentially closed peripheral surface (44), at the axial end of which a circumferential bearing edge (50) is formed which can be placed onto the valve seat and can be lifted off from the valve seat. On the axial side facing away from the actuating member, the control element has a radially inner axial inflow surface (66) and has a wall (46) which extends at least radially inwards from the peripheral surface (44) and in which at least one opening (52) is formed via which an interior space (54) of the blow-off valve is fluidically connected to the flow channel. The radially inner axial inflow surface is formed on a rotationally symmetrical inflow element (68) which has a radially inner central inflow point (72), from which the inflow surface extends continuously radially outwards as far as an outflow edge (74), the inflow surface having an axial distance from the actuating member which decreases as the radial distance from the central inflow point increases, and the at least radially extending wall with the at least one opening is offset in the direction of the actuating member with respect to the bearing edge and to the outflow edge.

Description

B E S C H R E I B U N G Divert air valve

The invention relates to a diverter valve with a flow housing with a flow channel between an inlet and an outlet, a valve seat formed between the inlet and the outlet, an actuator, an actuating element that can be moved translationally by means of the actuator, a control body attached to the actuating element, which has a radially outer circumference has closed lateral surface, at the axial end of which a circumferential support edge is formed, which can be placed on the valve seat and lifted from the valve seat, the control body having a radially inner axial flow surface on the axial side facing away from the actuating member, and a wall that extends extends from the lateral surface at least radially inward, and in which at least one opening is formed, through which an interior of the

Diverter valve is fluidically connected to the flow channel.

Diverter valves are used in a known manner for the recirculation of compressed fresh gas, optionally with recirculated exhaust gas from the pressure side of a compressor of a turbocharger back to the suction side of the compressor. The connection between the pressure side and the suction side of the compressor through a bypass line is required for the transition from a high load to the overrun mode of the internal combustion engine in order to prevent high delivery of the turbocharger compressor against a closed throttle valve and the resulting pumping effect.

Diverting air valves are often operated electromagnetically, the control body of the valve being controlled by the electromagnetic force via the armature is moved. A generic bypass valve is known, for example, from DE 10 2016 118 341 A1. The valve has a

Pressure compensation opening on the control body connected to the armature, whereby, with appropriate design of the effective surfaces, an equilibrium of forces is established with regard to the pneumatic forces acting on the control body, so that only the force of a spring has to be overcome for actuation, whereby the

Divert air valve has very short operating times. In this valve, the closure body is directly connected to the armature and the inside of the valve is separated from the outside area by a membrane. The problem arises, however, that with very low currents out of the closed position, the static pressure falls very quickly due to the dynamic pressure that arises, as a result of which a large force acts on the control body in the closing direction.

In previous generations of diverter valves, as described for example in EP 1 762 712 B1, an attempt was made to transfer this low static pressure generated when opening to the opposite side of the control body by bringing the openings directly up to the narrow opening area. However, this means that relatively large spring forces must be made available for closing and thus also relatively large forces for initiating the opening movement by the electromagnet, which must be made correspondingly large.

The task is therefore to provide a diverter valve with which, on the one hand, very fast actuating times can be achieved and, on the other hand, low electromagnetic actuating forces are required, whereby the installation space of the diverter valve and in particular the space for the solenoid can be reduced and thus the diverter valve can be manufactured more cheaply. This object is achieved by a diverter valve with the features of main claim 1.

The regulating body of the diverter valve according to the invention has a radially outer, circumferentially closed jacket surface, at the axial end of which a circumferential support edge is formed which can be placed on the valve seat and lifted off the valve seat, the support edge being understood to be a narrow circular surface that is narrow to the valve seat Valve seat tapers. The regulating body also has, on the axial side facing away from the actuating member, a radially inner axial flow surface which is connected at least indirectly to the jacket surface via an at least radially extending wall. At least one opening is formed in this wall, via which an interior of the diverter valve is fluidically connected to the flow channel, so that the same pressure is applied below and above the control body, at least as long as it is not moved.

According to the invention, the radially inner axial inflow surface is formed on a rotationally symmetrical inflow body, which has a radially inner central inflow point, from which the inflow surface extends continuously radially outward to an outflow edge, the inflow surface decreasing with increasing radial distance from the central inflow point having an axial distance from the actuating member, and wherein the at least radially extending wall with the at least one opening is offset from the support edge and the trailing edge axially in the direction of the actuating member. In this context, an outflow edge is understood to mean an edge from which the gas flow sliding along the inflow surface detaches from the outflow body, since it no longer has any component of extension radially outward. There is only a slight axial offset between the trailing edge of the inflow surface and the supporting edge of the control body, which means that the main air flow is the first time the valve is opened is not passed directly to the openings, but rather in the direction of the free gap between the valve seat and the support edge of the control body. Due to the axial distance between the wall and the support edge, the pressure difference that acts in the closing direction when opening, which is created by the flow, only acts on the thin support edge, so that only a very small closing force acts on the control body. By directing the current radially outwards and the low available

Attack surface for the while in the gap between the valve seat and the

The pressure generated by the control body creates a uniform force curve when opening with low necessary opening forces, since the flow generates a force in the opening direction, but only a portion of this force acts on the opposite side, since at the beginning of the opening only a portion of this flow also increases the pressure in the interior of the Valve is used. In this way, the electromagnet can be made smaller and still achieve fast opening and closing times.

The trailing edge and the supporting edge are preferably arranged in a common plane. It follows that when the opening process begins, the flow flows from the inflow body in the direction of the support edge, which results in a significantly reduced proportion of the

Air flow passes directly to the openings and to the opposite axial side of the control body. This reduces the force in the closing direction. In a preferred embodiment, the at least one opening in the at least radially extending wall is axially offset in the direction of the actuating member to the trailing edge that a tangent vector to the trailing edge of the inflow surface is the lateral surface on a relative to the wall in which the opening is formed, cuts away from the actuator side. This ensures that the air at the inlet does not flow directly to the openings and creates a corresponding counter pressure there. Furthermore, it is advantageous if the at least radially extending wall is offset so far in the direction of the actuating member that a first vector in the radial direction outward from the at least radially extending wall to the support edge to a plane that is spanned by the support edge , encloses at least an angle of 20 °. This has the consequence that the wall is set back so far that the falling pressure in the gap cannot act directly on the wall surface, as a result of which the force acting on the regulating body in the closing direction is reduced. In this context, radially outward is only to be understood as meaning that the vector has a radial component which points away from the center axis of the diverter valve. Of course, however, there will also be an extension component of the vector in the axial direction. This applies to all of the vectors mentioned in this application which, by definition, point radially outward.

Furthermore, it is preferred that the opening is offset so far in the direction of the actuator that a second vector in the radial direction outward from the opening to the support edge to a plane spanned by the support edge encloses at least an angle of 30 ° and that a third vector in the radial direction outward from the trailing edge to the opening to a plane that is spanned by the support edge encloses at least an angle of 30 °. In this way, the balance of forces is maintained even in the event of sudden changes in position and thus pressure changes on the surface facing the inlet at the two axial ends of the openings, as a result of which short actuating times are achieved and low actuating forces are required.

The inflow surface is preferably curved into the interior of the inflow body. This results in a gradual deflection of the flow with increasing radial and decreasing axial components as the distance from the inflow point increases. A directed flow becomes accordingly created with little vortex formation, whereby the flow is kept away from the openings in a targeted manner.

Furthermore, it is advantageous if the inflow body extends beyond the axial inflow surface from the outflow edge exclusively axially in the direction of the actuating element. This means that there are no eddies in any undercut that may be present.

In an advantageous embodiment, the wall in which the at least one opening is formed extends from the circumferentially closed jacket surface of the regulating body radially inward to a fastening section of the regulating body via which the regulating body is at least indirectly fastened to the actuating member. Such a one-piece body can be produced simply and inexpensively by plastic injection molding.

In addition, the inflow body is preferably designed as a cap which is fastened to the fastening section of the regulating body. This cap is also easy to manufacture and reliably closes spaces in which there are storage areas through which the force acting on the control body would be changed.

In a particularly preferred embodiment, the cap is fastened to the fastening section by means of a material or form-fitting connection. This connection can be made particularly simply by a clip connection, a welded connection or by gluing.

The control body is advantageously fastened to the actuating member via a base of a cup-shaped fastening element, with a radially outwardly pointing collar being formed at the axial end of the fastening element opposite the base, which collar axially against the Attachment portion of the control body is applied. In this way, a simple cardanic fastening of the regulating body on the actuating member can be produced, which enables the regulating body to align itself correctly with the valve seat during the closing process.

The cup-shaped fastening element is preferably covered axially by the cap in the direction of the inlet, so that it cannot act as a storage area through which the opening forces are changed. The actuator is preferably an electromagnet and the actuating element is the armature of the electromagnet. This enables short positioning times.

A diverter valve is thus created which has a high level of durability and tightness. Above all, however, the size of the electromagnet and thus the manufacturing costs can be significantly reduced, since the forces to be overcome during the opening process are reduced by the special outflow from the inflow element, in that on the one hand the direction of the flow is optimally set and on the other hand that available for a pressure difference Attack surfaces are reduced. In particular, the required opening forces are clearly evened out over the entire opening process, in particular a force peak shortly after the opening process has been initiated is avoided. An embodiment of a diverter valve according to the invention is shown in the figures and is described below.

The figure shows a side view of a diverter valve according to the invention in a sectional illustration.

The diverter valve shown in the figure consists of an actuator 10 designed as an electromagnet, in the housing 12 of which there is a coil 14 is wound on a bobbin 16. A magnetizable core 18 is fastened in the radially inner region of the coil carrier 16, the axial end of which protrudes beyond the coil carrier 16, the core 18 being surrounded at this axial end by a return plate 20 which is connected to an iron jacket 22 surrounding the coil 14 . At the end of the coil carrier 16 opposite to the core 18 there is a further return plate 24, which extends in the radially outer area with the iron jacket 22 and in the radially inner area into the coil carrier 16. In the interior of this section, a cup-shaped sliding bushing 26 is arranged, which extends as far as the core 18 and in which an armature acting as an actuating member 28 is mounted. When the coil 14 is energized, this armature is drawn to the core 18 and into its recess 30 by the electromagnetic force. The coil 14 is supplied with power via contacts which open into a connector (not shown).

A regulating body 32 is attached to the actuating member 28, by means of which a flow cross-section of a flow channel 36 formed in a flow housing 34, which connects an inlet 38 with an outlet 40, can be released or shut off by lowering the regulating body 32 onto a valve seat 42 surrounding the flow cross-section or is lifted from it.

The regulating body 32 consists of a radially outer, circumferentially closed, cylindrical jacket surface 44, from which a wall 46 extends radially inward at approximately half the height to a fastening section 48, which also has a substantially hollow cylindrical shape and is concentric to the jacket surface 44 is formed. On the axial side of the lateral surface facing away from the actuating member 28, a support edge 50 is formed, with which the control body 32 rests on the valve seat 42 in the closed state of the diverter valve. In the radially extending wall 46 of the regulating body 32, several axial bores are formed which, as openings 52, enable pressure equalization between the bottom and the top of the regulating body 32 or an interior space 54 of the diverter valve and the bottom of the regulating body 32. The effective diameter for resting on the valve seat 42 essentially corresponds to the diameter of the cylindrical jacket surface 44, whereby a force equilibrium of the pneumatic forces acting on the control body 32 is established in the static state

The regulating body 32 is fastened to the actuating member 28 by means of a cup-shaped fastening element 56, which can be produced by deep drawing, in that a base 58 is arranged in a central circular recess 60 at the axial end of the actuating member 28 and is fastened at this point by welding. A cylindrical section 62 adjoining the bottom 58 extends to the end of the fastening section 48 of the regulating body 32 facing away from the actuating member 28 and has an outer diameter which is smaller than the inner diameter of the fastening section 48. This cylindrical section 62 adjoins it the axial side opposite to the bottom 58 has a radial annular widening in the form of a collar 64 which is arranged axially opposite to the fastening section 48. The distance of the collar 64 to the bottom 58 of the fastening element 56 is selected so that a small gap remains between the fastening section 48, when the fastening section 48 is in contact with the actuating member 28, and the collar 64 of the fastening element 56, so that the lateral surface 44 is slightly towards the Fastening element 56 and thus also to the actuating member 28 can be tilted. In this way, a cardanic fastening of the control body 32 on the actuating member 28 is realized. The control body 32 also has a radially inner axial flow surface 66, which in the present exemplary embodiment is formed on a flow body 68, which is designed as a cap 70, over which the cup-shaped fastening element 56 is covered, through which the control body 32 is fastened to the actuating member 28 is.

The inflow body 68 has a central inflow point 72, from which the further inflow surface 66 extends outwards in a rotationally symmetrical manner. The inflow surface 66 is curved inward toward the fastening element 56, so that the inflow body 68 extends with one component radially outward and one component in the axial direction toward the actuating member 28. The radial portion of a tangent vector on the inflow surface 66 increases with increasing radial distance from the inflow point 72 last imposed flow direction continues to flow. The trailing edge 74 has approximately the same axial distance from the actuating member 28 as the supporting edge 50 of the control body 32. From the trailing edge 74, the cap 70 extends only axially in the direction of the fastening section 48 of the control body 32, where the cap 70 is welded is attached. A tangent vector 76 to the trailing edge 74, i.e. a tangent to the inflow surface 66, which is directed towards the inlet 38 in the radially outer area, points into an area of the cylindrical outer surface 44 between the support edge 50 and the wall 46 Openings 52 deflected away in the direction of the opening cross section between the valve seat 42 and the support edge 50. Furthermore, there is a clear influence from the arrangement of the wall 46 and the openings 52 to the support edge 50 and to the trailing edge 74 any point of the wall 46 extends radially outward in the direction of the support edge 50, to a plane 80 which is spanned by the support edge 50, enclose an angle of at least 20 °. In the exemplary embodiment, this angle is between 40 ° and 80 °.

In addition, an angle between a second vector 82, which extends radially outward from one of the openings 52 to the support edge 50, to the plane 80 should also be at least 30 °. In the present exemplary embodiment, this is approximately 60 °. An angle between a third vector 84, which extends radially outward from the trailing edge 74 to one of the openings 52, should also be at least 30 ° with respect to the plane 80. In the present exemplary embodiment, this angle is approximately 56 °. This arrangement of the trailing edge 74, the supporting edge 50 and the wall 46 and the openings 52 to one another results in almost no contact surface for a decreasing pressure in the gap between the valve seat 42 and the regulating body 32 due to the flow when opening. The pressure difference that otherwise arises due to the flow is also reduced by the targeted diverting of the flow away from the openings 52.

When the valve is actuated, the regulating body 32 plunges into the interior space 54, which is bounded radially by a housing wall 86, at the end of which is remote from the actuator 10 an annular plate 88 is attached, the inner diameter of which is slightly larger than the outer diameter of the outer jacket surface 44. A V-shaped seal 90 with two legs rests on this plate 88, the first of which rests against the circumferentially closed jacket surface 44 and the second leg rests against the radially delimiting housing wall 86, so that the interior 54 in the closed state of the valve is connected exclusively via the openings 52 to the inlet 38 below. To the central To supply the recess 30 between the actuating member 28 and the core 18 with a corresponding pressure and thus to create a pressure-balanced valve, one or more grooves are arranged on the outer circumference of the actuating member 28.

Furthermore, a spring 92 is arranged in the interior 54, which rests axially against the wall 46, and whose opposite axial end rests against the end of the sliding bush 26 of the actuator 10, whereby when the coil 14 is not energized, the regulating body 32 is in its on the valve seat 42 is placed in the resting state. In this static state there is an equilibrium of forces, so that the spring 92 can be designed in such a way that the diverter valve remains in the closed state even when pressure pulsations occur. To open the actuator 10 is energized, only the force of the spring 92 has to be overcome. As soon as a gap between the valve seat 42 and the support edge 50 is released, a flow arises through this gap. The influence of the static pressure fluctuations that arise as a result is largely avoided, since the wall 46 is sufficiently far away from the valve seat 42 and only the thin support edge 50 can serve as a contact surface for the pressure difference. Pressure equalization can also take place in the interior space 54, since no flow acts directly on the openings 52 through the flow line by means of the inflow body 68, whereby a static pressure equalization takes place more quickly when opening, which would otherwise be inhibited and thus lead to an additional force acting in the closing direction would.

Correspondingly, very fast actuating times can be achieved with a very small and therefore inexpensive to manufacture electromagnet.

It should be clear that the present invention is not limited to the exemplary embodiment described. So can someone else Actuator can be used, or the outer circumferential surface and the at least radially extending wall are made in several pieces. The inflow element can optionally also be produced in one piece with the rest of the control body.

Claims

Pierburg GmbH, 41460 Neuss

PATENT CLAIMS 1. Diverter valve with a flow housing (34) with a flow channel (36) between an inlet (38) and an outlet (40), a valve seat (42) formed between the inlet (38) and the outlet (40), an actuator (10), an actuating member (28) which can be moved translationally by means of the actuator (10), a regulating body (32) which is fastened to the actuating member (28) and has a radially outer circumferentially closed jacket surface (44), at the axial end of which a circumferential Support edge (50) is formed, which can be placed on the valve seat (42) and lifted off the valve seat (42), the control body (32) having a radially inner axial flow surface (66) on the axial side facing away from the actuating member (28) , and has a wall (46) which extends from the lateral surface (44) at least radially inward, and in which at least one opening (52) is formed, via which an interior (54) of the diverter valve with the flow channel (36 ) is fluidically connected, characterized in that the radially inner axial inflow surface (66) is formed on a rotationally symmetrical inflow body (68) which has a radially inner central inflow point (72) from which the inflow surface (66) extends steadily in a radial direction extends on the outside as far as a trailing edge (74), with the inflow surface (66) increasing the radial distance from the central inflow point (72) a decreasing axial distance from the actuating element (28) and wherein the at least radially extending wall (46) with the at least one opening (52) is offset axially in the direction of the actuating member (28) to the support edge (50) and to the trailing edge (74).

2. Diverter valve according to claim 1, characterized in that the trailing edge (74) and the supporting edge (50) are arranged in a common plane (80).

3. Diverter valve according to claim 1 or 2, characterized in that the at least one opening (52) in the at least radially extending wall (46) is offset so far axially in the direction of the actuating member (28) to the trailing edge (74) that a Tangent vector (76) to the trailing edge (74) of the inflow surface (66) intersects the lateral surface (44) on a side facing away from the actuating member (28) with respect to the wall (46) in which the at least one opening (52) is formed .

4. Diverting air valve according to one of the preceding claims, characterized in that the at least radially extending wall (46) is offset so far in the direction of the actuating member (28) that a first vector (78) in the radial direction outward from the at least radially extending wall (46) to the support edge (50) to the plane (80) which is spanned by the support edge (50) encloses at least an angle of 20 °.

5. Diverter valve according to one of the preceding claims, characterized in that the at least one opening (52) is offset so far in the direction of the actuating member (28) that a second vector (82) in the radial direction outward from the opening (52) to the support edge (50) to the plane (80) which is spanned by the support edge (50), encloses at least an angle of 30 ° and that a third vector (84) in the radial direction outward from the trailing edge (74) to the opening (52) to the plane (80) passing through the support edge (50) is stretched, encloses at least an angle of 30 °.

6. Diverter valve according to one of the preceding claims, characterized in that the inflow surface (66) is curved into the interior of the inflow body (68).

7. Diverter valve according to one of the preceding claims, characterized in that the inflow body (68) extends beyond the axial inflow surface (66) from the trailing edge (74) exclusively axially in the direction of the actuating member (28).

8. Diverting air valve according to one of the preceding claims, characterized in that the wall (46) in which the at least one opening (52) is formed extends radially inward from the circumferentially closed jacket surface (44) of the control body (32) a fastening section (48) of the regulating body (32), via which the regulating body (32) is fastened at least indirectly to the actuating member (28).

9. Diverter valve according to claim 8, characterized in that the inflow body (68) is designed as a cap (70) which is fastened to the fastening section (48) of the regulating body (32).

10. Diverting air valve according to claim 9, characterized in that the cap (70) is attached to the attachment portion (48) with a material fit or a form fit.

11. Diverter valve according to one of claims 8 to 10, characterized in that the control body (32) via a base (58) of a cup-shaped fastening element (56) is fastened to the actuating member (28), wherein the axial end of the opposite to the base (58) Fastening element (56) a radially outwardly pointing collar (64) is formed, which rests axially against the fastening section (48) of the control body (32).

12. Diverter valve according to claim 11, characterized in that the cup-shaped fastening element (56) is covered axially by the cap (70) in the direction of the inlet (38).

13. Diverter valve according to one of the preceding claims, characterized in that the actuator (10) is an electromagnet and the actuating member (28) is the armature of the electromagnet.