EP3387245A1

EP3387245A1 - Regulating device for an internal combustion engine

Info

Publication number: EP3387245A1
Application number: EP16795065.8A
Authority: EP
Inventors: Dirk VIERKOTTEN; Maximilian Flender; Christian Vigild; Andreas Kuske; Franz Arnd Sommerhoff; Jörg Kemmerling; Helmut Kindl; Vanco Smiljanovski; Hanno Friederichs
Original assignee: Pierburg GmbH; Ford Werke GmbH
Current assignee: Pierburg GmbH; Ford Werke GmbH
Priority date: 2015-12-11
Filing date: 2016-11-14
Publication date: 2018-10-17
Anticipated expiration: 2036-11-14
Also published as: WO2017097540A1; DE102015121616A1; US20190003401A1; US10767570B2; CN108431394B; EP3387245B1; CN108431394A; DE102015121616B4

Abstract

Regulating devices for internal combustion engines are known, having an intake pipe (12), an exhaust gas recirculation pipe (16) that opens into the intake pipe (12), a housing (10) in which the intake pipe (12) and the exhaust gas recirculation pipe (16) are formed and a shaft (28) acting as an axis of rotation (30) on which a regulating element (36) is eccentrically mounted, the shaft being arranged perpendicularly to the centre line of the intake pipe (12) and of the exhaust gas recirculation pipe (16), wherein in a first end position, in which the intake pipe (16) is at least choked upstream of an opening in the exhaust gas recirculation pipe (16), a normal vector of a first surface (44) of the regulating element (36) points to the upstream portion of the intake pipe (12), and in a second end position, in which the exhaust gas recirculation pipe (16) is closed, a normal vector of a second surface (50) of the regulating element (36) points to the exhaust gas recirculation pipe (16). However, these regulating devices have the inconvenient that the introduction of the exhaust gas disturbs the flow and thus leads to increased condensate formation and increased flow resistances. In order to solve this problem, the invention proposes the formation of guide ribs (52) on the second surface (50), along which an exhaust gas stream flows into the intake pipe (12) when the exhaust gas recirculation pipe (16) is opened.

Description

DESCRIPTION

Regulating device for an internal combustion engine

The invention relates to a control device for an internal combustion engine having an intake passage, an exhaust gas recirculation passage, which opens into the intake passage, a housing in which the intake passage and the exhaust gas recirculation passage are formed, serving as a rotation axis shaft on which a control body is mounted eccentrically, and is arranged perpendicular to the central axes of the intake passage and the exhaust gas recirculation passage, wherein in a first end position, in which the intake passage upstream of an opening of the exhaust gas recirculation passage is at least throttled, a normal vector of a first surface of the control body to the upstream side of the intake passage and in a second end position, in which the exhaust gas recirculation channel is closed, has a normal vector of a second surface of the control body to the exhaust gas recirculation channel.

Such control devices are used in internal combustion engines to control the gas flow to be introduced into a cylinder of an internal combustion engine with respect to its composition of recirculated exhaust gas amounts or freshly drawn air quantities. Depending on the operating state of the internal combustion engine, different mixing ratios must be set in order to achieve minimum exhaust gas values and maximum power values.

For a control either two separate valves can be used, then a total amount of control over the two valves is possible or these control valves contain two valve bodies, which are actuated by a common actuating device, so that only the mixture is changed. This embodiment is used in particular in turbocharged engines in which the Gesamtansaugmenge can be controlled by the performance of the compressor. In order to be able to perform a corresponding control device even smaller, it is also known to use only a control body instead of two control body, which cooperates with both channels. In these embodiments, the exhaust gas recirculation passage usually opens immediately downstream of serving as a throttle valve flap in the air intake passage. If the exhaust gas recirculation rate is increased as desired, the throttle flap is closed to the same extent when the exhaust gas recirculation valve is opened, which in addition to the increase in the free cross section of the exhaust gas recirculation channel also results in an increase in the pressure gradient in the exhaust gas recirculation channel, whereby the proportion of exhaust gas is increased compared to the intake air quantity ,

Such an arrangement is disclosed, for example, in DE 10 2012 101 851 B4, in which two flaps arranged in parallel are actuated via a common rotary shaft, so that with rotation of the two flaps, the first flap moves away from the valve seat of the air intake duct, while the second flap the valve seat of the exhaust gas recirculation passage, which is arranged perpendicular to the valve seat of the air intake duct, approaches until the air intake passage is fully opened and the exhaust gas recirculation passage is completely closed. Both for the second flap, which dominates the exhaust gas recirculation channel, and for the first flap, which dominates the air intake channel, the valve seats are each designed as stops, against which the flaps rest circumferentially in their position closing the respective channel. The rotary shaft is disposed on a housing wall between the mouth of the exhaust gas recirculation passage and the valve seat in the air intake passage, so that the flow is not affected by the shaft. In the area of the mouth of the exhaust gas recirculation channel is additionally a swirl generator arranged, over which the exhaust gas flow to improve the mixing with the air flow is imparted a twist.

In addition, from US 2009/0283076 AI a flap is known, which is arranged in an intake passage and in the interior of which a channel is formed, which is flowed through with exhaust gas, which is introduced at the opposite end of the shaft in the air flow. By this arrangement, a good mixing of the two gas streams is achieved, however, both the production of the flap is very expensive and the connection of the exhaust gas recirculation channel for valve inside not possible without leakage. A regulation of the recirculated exhaust gas quantity is not possible with this flap.

Also known from DE 10 2006 051 987 B4 is a centrally mounted control flap, on the surface of which a plurality of ribs extending perpendicularly to the flap shaft are formed, which serve to straighten the gas flow.

Although these known arrangements a good control of the exhaust gas recirculation system is achieved while minimizing costs and components, but it has been found that, especially in low-pressure exhaust gas recirculation systems, by turbulence resulting from the mixture of exhaust gas flow with the air flow, the performance of the downstream compressor of the turbocharger or of an electric compressor is adversely affected. Furthermore, problems may arise due to condensation, if the moist exhaust gas flow is conducted directly into the cold air flow or against cold duct walls. These condensates in the gas stream can also cause damage to the compressor.

It is therefore an object of the invention to provide a control device for an internal combustion engine, with the good controllability of the air flow and the exhaust gas flow compared to known Versions a performance increase of a downstream compressor can be achieved and damage due to condensation occurring can be reliably avoided.

This object is achieved by a control device for an internal combustion engine with the features of the main claim.

Characterized in that on the second surface Leitrippen are formed, along which flows an exhaust gas flow when opening the exhaust gas recirculation passage in the intake passage, the recirculated exhaust gas flow can be directed directed into the intake passage. Depending on the design and arrangement of the guide ribs, both a condensation of the water in the exhaust gas can thereby be avoided as well as a reduction in performance of the compressor can be prevented by a poor flow of the impeller and resulting flow resistance due to turbulence occurring.

Preferably, a first valve seat is formed in the intake passage, on which the control body rests with its first surface in its first end position. By such an axial support of the surface on the valve seat an almost leak-free closure of the intake passage is achieved.

Furthermore, it is advantageous if a second valve seat is formed at the mouth of the exhaust gas recirculation passage, against which the second surface of the control body rests in its second end position with a guide rib free area. Thus, the exhaust gas recirculation channel can be closed very well sealed in spite of the guide ribs by an area is used for the axial support of the surface on the valve seat, on which no guide ribs are formed. In an alternative advantageous development, the control body has an eccentrically mounted on the shaft flap with the first and the second surface and a coupling member that extends from the second surface and on which a closing member is formed, which cooperates with the second valve seat, wherein the guide ribs extend from the second surface to at most the closing member.

The baffles advantageously extend parallel to one another along the second surface, whereby a rectification of the exhaust gas flow takes place, which leads to low pressure losses and makes it possible to direct the exhaust gas flow targeted.

In a further advantageous embodiment, the guide ribs extend perpendicular to the axis of rotation of the control body. The exhaust gas flow is thus introduced specifically at low pressure losses straight into the air flow. Thus, the mixed gas stream can be introduced in parallel and straight into a subsequent compressor inlet, whereby its efficiency is increased.

Alternatively, it is possible for the guide ribs to extend at a fixed angle to the axis of rotation of the regulating body. Such an embodiment can impose an angle to the main flow direction of the air flow to the exhaust flow, whereby a spiral flow can be generated to improve performance at the inlet of the compressor.

An even stronger spiral flow with reduced pressure loss is achieved by the guide ribs having a growing inclination to a perpendicular to the axis of rotation with increasing distance from the axis of rotation. Alternatively, it is advantageous to form the guide ribs in the extension direction from the axis of rotation to the end remote from the axis of rotation inclined to each other. This means that a kind of fan is spanned by the ribs whose narrow end is formed on the side of the flap remote from the shaft. In this way, the exhaust gas is bundled and can be targeted example meadow introduced into remote areas, whereby the condensation of water occurring from the exhaust gas can be reduced at cold pipe walls, whereby the life of the compressor is increased.

Preferably, the second surface is curved. Such a curvature also serves to direct the exhaust gas flow into a desired area. Thus, for example, in a convex formation results in an introduction into the air flow, with a concave formation of the curvature an introduction without much mixing with the air flow in the flow shadow of the flap. The curvature is also used accordingly to direct the exhaust gas flow with the lowest possible pressure loss in desired areas of the channel.

Accordingly, the guide ribs are preferably formed such that the exhaust gas stream can be introduced into a defined region of the intake duct. This may depend on the training and subsequent channel guides. Depending on the combustion engine, either a good mixing, a layer flow, straight or swirl flows may be desired. Depending on the required flow, a corresponding position of the guide ribs can be formed to improve the engine performance.

In addition, it is advantageous if a plane spanned by the first valve seat encloses an angle of 70 ° to 80 ° with respect to a plane spanned by the second valve seat. Such a smaller adjustment angle means that over the entire adjustment range the air and the exhaust gas flow are also changed when the flap is rotated. In this adjustment range, therefore, the slope of the control curve remains essentially unchanged.

Preferably, the first valve seat has a smaller circumference than the portion of the intake passage downstream of the first valve seat and the control body dips in its recess closing the exhaust gas recirculation passage in a recess in the intake passage disposed in the flow shadow of the upstream portion of the intake passage. This means that when the intake passage is open no flow resistance through the flap is present, so that the compressor is supplied with a larger air flow. In addition, the channel is substantially extended by the applied flap, so that a vortex formation behind the valve seat, which would also lead to flow losses, is also prevented.

Thus, a control device is provided with which both the air mass flow in the intake passage and the exhaust gas mass flow of the exhaust gas recirculation loop can be regulated, wherein at the same time the performance of a subsequent compressor for charging an internal combustion engine is optimized by improved flow guidance. The flow guidance can be adapted by the guide ribs to the respective requirements of the internal combustion engine or to the existing required inflow conditions of the compressor used. By preventing condensation of the water vapor conveyed with the exhaust gas damage to the compressor and in particular to its ribbing are prevented.

An embodiment of a control device according to the invention is shown in the figures and will be described below.

1 shows a perspective view of a control device according to the invention in a sectional view. Figures 2 a) to d) show schematically possible arrangements of the guide ribs of a control device according to the invention.

The control device according to the invention consists of a housing 10 which defines an intake passage 12 and to which an orifice 14 of an exhaust gas recirculation passage 16 is formed. The intake passage 12 extends substantially in a straight line to an axial inlet of a compressor housing of a turbocharger, not shown, while the exhaust gas recirculation passage 16 opens approximately perpendicular to the intake passage 12 in this.

The housing 10 consists of a first substantially tubular intake housing 18, the downstream end of which is obliquely formed and encloses an angle a of approximately 80 ° to a central axis of the intake passage 12. This suction housing 18 protrudes with this downstream end into a mixing housing 20, or is inserted into the mixing housing 20 until it abuts a flange 22, via which the suction housing 18 is fastened by means of screws 24 to the mixing housing 20.

The mouth 14 of the exhaust gas recirculation passage 16 projects laterally into an opening 26 of the mixing housing 20 and is formed as a separate housing part. The mixing housing 20 forms an extension of the intake passage 12, which in turn subsequently opens into the axial inlet of the compressor housing. In the mixing housing 20, a shaft 28 is rotatably mounted about an axis of rotation 30, which can be actuated via an actuator 32. The axis of rotation 30 of this shaft 28 is disposed perpendicular to the center axes of the intake passage 12 and the exhaust gas recirculation passage 16 and is located between the mouth 14 of the exhaust gas recirculation passage 16 at the upstream end of the exhaust gas recirculation passage 16 and the axial end of the intake housing 18 at the exhaust gas recirculation passage 16 shrewd side. The flow cross section of the intake housing 18 is smaller than that of the mixing housing 20, wherein the suction housing 18 is fixed to the mixing housing 20 so that a recess 34 formed downstream of the mouth 14 of the exhaust gas recirculation passage 16 is disposed in the flow shadow of the air flow from the suction housing 18, in which the shaft 28 penetrates the mixing housing 20 ,

At this eccentrically arranged in the intake passage 12 shaft 28, a control body 36 is attached, which consists of a flap 38 and a via a coupling member 40 attached to the first flap 38 closing member 42. The flap 38 extends from the shaft 28 into the interior of the mixing housing 20 and dominates the flow area of the intake passage 12. For this purpose, the flap 38 cooperates with its first surface 44 with the axial end of the suction housing 18, which serves as a first valve seat 46, on which the flap 38 abuts in the intake channel 12 occluding state with its first surface 44 in a first end position, so that in this state, a normal vector of the first surface 44 to the upstream side of the intake passage 12 and the intake housing 18 points.

In the flap 38, a bore is formed, in which the coupling member 40 is fixed to the flap 38. This coupling member 40 extends to the suction housing 18 opposite side perpendicular to the flap 38 and penetrates with its opposite end the closing member 42, which in turn is attached to this end of the coupling member 40. This attachment of the closing member 42 causes a rotation of the shaft 28 in a second end position in which the closing member 42 rests on a formed at the end of the mouth 14 of the exhaust gas recirculation passage 16 second valve seat 48, a closure of the exhaust gas recirculation passage 16.

According to the invention, a plurality of guide ribs 52 are formed on a second surface 50 opposite the first surface 44 of the flap 38, extending from the second surface 50 to the second surface 50 Closing member 42 extend, so that these guide ribs 52 are arranged with closed exhaust gas recirculation passage 16 opposite to its mouth 14 without extending into the mouth 14. In this second end position, a normal vector of the second surface 50 points into the exhaust gas recirculation passage 16. A flow of exhaust gas is conducted accordingly along opening of the exhaust recirculation passage 16 along these guide ribs 52.

In the first embodiment shown in Figure 1, these guide ribs 52 extend parallel to each other and perpendicular to the shaft 28. They are either cohesively connected to the flap 38 or made in one piece with this. If the control body 36 consisting of the flap 38, the guide ribs 52, the closing element 42 and the coupling element 40 is now in the position shown in FIG. 1, the exhaust gas flow is rectified and introduced into the air flow, so that a uniform, slowly running mixing without greater turbulence and consequent low pressure loss takes place. This low flow resistance causes a large amount of mixed gas to be supplied to the compressor via the compressor inlet, thereby increasing the power of the following internal combustion engine.

In this context, it should be noted that it is of course also possible to dispense with the additional coupling member 40 and the additional closing member 42 and to use the second surface 50 of the flap 38 directly for closing the second valve seat 48. In such an embodiment, it is only necessary not to carry out the area resting on the second valve seat 48 with guide ribs 52 and the guide ribs 52 so arranged that the rotational movement of the shaft 28 from the exhaust gas recirculation passage 16 closing end position not by abutting the guide ribs 52 at Channel walls 54 of the exhaust gas recirculation passage 16 is disturbed. FIG. 2 shows various further advantageous embodiments of these guide ribs 52, the shape and arrangement of which may differ depending on the design and size of the following compressor and of the internal combustion engine and areas of use.

Thus, Figure 2 shows a) guide ribs 52 on the second surface 50 of the flap 38, which are employed at an angle of about 20 ° to a perpendicular to the axis of rotation of the shaft 28. This has the consequence that an exhaust gas flow is deflected by these guide ribs 52 to the side and a swirl in the mixed gas stream is generated upon entry of the exhaust gas flow into the air flow. This leads to a faster mixing of the two gas streams and usually leads to an increase in performance of the compressor by the swirling inflow.

Also, the version shown in Figure 2 b) has such a performance increase of the following compressor due to an imposed twist result, but with reduced flow resistance and thus increased total mixing gas flow. In this version, the again parallel guide ribs 52 are formed arcuate, wherein the inclination to the perpendicular to the axis of rotation of the shaft 28 with increasing distance from the shaft 28 also increases. As a result of this gradual deflection of the exhaust gas flow in comparison with the version shown in FIG. 2 a), less turbulence results and, as a result, the flow resistance decreases.

FIG. 2 c) shows another possible embodiment of the guide ribs 52 on the surface 50. The distance between these guide ribs 52 decreases with increasing distance from the shaft 28. This means that the guide ribs 52 have an inclination to one another. In the illustrated embodiment, the exhaust stream is concentrated centrally. Any other bundling to another location of the intake passage 12 would be conceivable with such a version, wherein the central introduction of the exhaust gas flow has the advantage that the hot and steam-transporting exhaust gas flow is introduced into an area in which it is not passed directly to the depending on the ambient conditions may cold walls 56 of the intake duct 12. Accordingly, an optionally occurring condensation of the water is significantly reduced, which in turn prevents damage to the blades of the compressor.

In the embodiment shown in Figure 2 d), the guide ribs 52 are again formed perpendicular to the axis of rotation 30, but they are located on a concave in cross-section surface 58, which means that the exhaust stream is not passed directly into the air stream, but in the Mixed housing 20 creates a layer flow through which too rapid cooling of the exhaust gas stream can be prevented by mixing with an optionally cold air flow.

The described control device is thus suitable for the very exact metering of an exhaust gas mass flow into an air mass flow and for exact control of the air mass flow with only one actuator, the flows can be directed almost arbitrarily by the use of guide ribs on the second surface of the flap to the performance of To optimize internal combustion engine or the performance of a downstream compressor, without having to use further installations. For this purpose, the exhaust gas stream can be rectified, bundled or acted upon by a corresponding arrangement of the ribs. In addition, it can either be kept away from the airflow or be routed directly into it. In addition to mixing levels that can be influenced in this way, flow resistances or condensation of the exhaust gas can be influenced. It should be understood that the scope of the present application is not limited to the embodiment described. Various versions of the position of the guide ribs are also conceivable, as well as different shapes of the surfaces of the flap. In addition, as described, it is possible to carry out the control device with or without an additional closing member.

Claims

P A T E N T A N S P R E C H E

Regulating device for an internal combustion engine with

an intake passage (12),

an exhaust gas recirculation passage (16) opening into the intake passage (12),

a housing (10) in which the intake passage (12) and the exhaust gas recirculation passage (16) are formed,

a rotary shaft (30) serving as a shaft (28) on which a control body (36) is mounted eccentrically, and which is arranged perpendicular to the center axes of the intake passage (12) and the exhaust gas recirculation passage (16),

wherein in a first end position in which the intake passage (12) upstream of an orifice of the exhaust gas recirculation passage (16) is at least throttled, a normal vector of a first surface (44) of the control body (36) to the upstream side of the intake passage (12) and in a second end position, in which the exhaust gas recirculation passage (16) is closed, a normal vector of a second surface (50) of the control body (36) to the exhaust gas recirculation passage (16),

characterized in that

on the second surface (50) guide ribs (52) are formed, along which an exhaust gas flow when opening the exhaust gas recirculation passage (16) into the intake passage (12).

Control device for an internal combustion engine according to claim 1,

characterized in that

in the intake passage (12), a first valve seat (46) is formed, on which the control body (36) rests with its first surface (44) in its first end position. Control device for an internal combustion engine according to one of claims 1 or 2,

characterized in that

at the mouth (14) of the exhaust gas recirculation passage (16), a second valve seat (48) is formed, against which the second surface (50) of the control body (36) rests in its second end position with a rib free area.

Control device for an internal combustion engine according to one of claims 1 or 2,

characterized in that

the regulating body (36) has a flap (38) mounted eccentrically on the shaft (28) with the first surface (44) and the second surface (50) and a coupling member (40) extending from the second surface (50) extends and on which a closing member (42) is formed, which cooperates with the second valve seat (48), wherein the guide ribs (52) from the second surface (48) to at most extend to the closing member (42).

Control device for an internal combustion engine according to one of the preceding claims,

characterized in that

the guide ribs (52) extend parallel to one another along the second surface (50).

Control device for an internal combustion engine according to claim 5,

characterized in that

the guide ribs (52) extend perpendicular to the axis of rotation (30) of the control body (36).

7. Control device for an internal combustion engine according to claim 5,

characterized in that

the guide ribs (52) extend at a fixed angle to the axis of rotation (30) of the control body (36).

8. Control device for an internal combustion engine according to claim 5,

characterized in that

the guide ribs (52) with increasing distance to the rotation axis (30) have a growing inclination to a perpendicular to the rotation axis (30).

9. Regulating device for an internal combustion engine according to one of claims 1 to 4,

characterized in that

the guide ribs (52) in the extension direction from the axis of rotation (30) from the end remote from the axis of rotation (30) are mutually inclined.

10. Control device for an internal combustion engine according to one of the preceding claims,

characterized in that

the second surface (50) is arched.

11. Control device for an internal combustion engine according to one of the preceding claims,

characterized in that

the guide ribs (52) are formed such that the exhaust gas flow into a defined region of the intake passage (12) can be introduced.

12. Control device for an internal combustion engine according to one of the preceding claims,

characterized in that

a plane spanned by the first valve seat (46) encloses an angle of 70 ° to 80 ° with respect to a plane defined by the second valve seat (48).

13. Control device for an internal combustion engine according to one of the preceding claims,

characterized in that

the first valve seat (46) has a smaller circumference than the first valve seat (46) downstream portion of the intake passage (12) and the control body (36) in its the exhaust gas recirculation passage (16) closing the second end position in a recess (34) in the intake passage (46) 12) disposed in the flow shadow of the upstream portion of the intake passage (12).