DE102007052244A1 - Internal combustion engine with an exhaust gas turbocharger - Google Patents

Abstract

The invention relates to an internal combustion engine having an exhaust gas turbocharger and an exhaust gas tract (3), which has an exhaust gas line (6) with a longitudinal axis (36), wherein a flow-through exhaust gas guide section (13) of the exhaust gas turbocharger (9) is arranged in the exhaust gas line (6), and having a Sc (31) and a lever arm (34) with a maximum travel angle (beta), wherein the closing body (31) upstream of the exhaust guide portion (13) within the exhaust pipe (6), a closed position ingestible, is arranged, in which the closing body (31) positions a flow surface (37) in the exhaust pipe (6) such that a closing angle (α) is formed between the flow surface (37) covered by the closing body (31) and the longitudinal axis (36), which is less than 90 °. The invention is used predominantly in vehicle construction.

Description

The The invention relates to an internal combustion engine with an exhaust gas turbocharger according to the preamble of claim 1.

to Performance increase of internal combustion engines, it is widely used when arranging a single exhaust gas turbocharger in an exhaust tract the internal combustion engine, a bypass line for so-called bypassing to provide a turbine wheel of the exhaust gas turbocharger or in addition to use a second exhaust gas turbocharger for a first exhaust gas turbocharger, wherein a parallel or a serial arrangement of the exhaust gas turbocharger is possible.

Indeed There are operating areas of the internal combustion engine in which a bypass or a simultaneous operation of the exhaust gas turbocharger not necessary is. To control the operation of the turbocharger are to Controls in the form of locking devices, which electronically and / or mechanically and / or pneumatically adjustable are used. These locking devices are in one Exhaust tract of the internal combustion engine usually in one Exhaust portion of the exhaust gas turbocharger upstream of a in the exhaust guide section rotatably mounted turbine wheel in a free flow cross-section which it to lock or is to be released.

The Closing devices have a closing body which positions in the free flow cross section is. The closing body is usually for positioning about an axis of rotation of the locking device rotatable. The closing body is between two stop positions movable, wherein the first stop position a so-called closed position, in which the closing body closes the free flow cross-section as completely as possible, and the second stop position, a so-called opening position is, in which the closing body the free flow cross-section as far as possible for the locking device is free. Between these two stop positions is like that formed movement angle.

in the Generally, closing devices are so-called wastegate valves used, which is a targeted control of the positioning of the closing body depending on a voltage applied to a compressor wheel Allow boost pressure, so that the corresponding, free flow cross section after At will the desired operating condition of the internal combustion engine adapted, fully or partially released or can be locked. Here is the closing body in an intermediate position arranged between the two stop positions or one of the two stop positions positioned.

Of the Disadvantage of these locking devices can be seen in the fact that they have a small movement angle due to their design. This movement angle is usually between approx. 45 ° and 65 °. Due to the small angle of motion in the open position, in which the free flow cross section should be completely free, a flow obstacle because the closing body due to its limited maximum movement angle is not completely out of the free Flow cross-section is removable.

From the JP 021 53 226 A1 is an internal combustion engine with an exhaust gas turbocharger, the internal combustion engine having an exhaust tract with an exhaust pipe, in which an exhaust gas guide portion of the exhaust gas turbocharger is arranged. Upstream of the exhaust gas guide section, a closing device for releasing or blocking a free flow cross section of the exhaust gas line is provided in the exhaust gas line. The closing device is designed in the form of a non-return valve and has a closing body, which is designed to cover the free flow cross-section. The closing device furthermore has an axis of rotation about which the closing body is rotatably positioned. In an unobstructed state, the closing body has a maximum angle of movement of 360 ° about the axis of rotation. An advantage of the non-return valve can be seen in this large angle of motion, since in a built-in state of the closing device thus the closing body is completely removed from the free flow cross-section, so that a disturbance of the flow due to the closing body can be excluded. A disadvantage, however, is to be seen in the fact that an influence on the release or the blocking of the free flow cross-section takes place exclusively thermodynamically as a function of the applied pressure at the non-return valve, that is, the pressure upstream of a turbine wheel. Targeted control of the non-return valve is not possible.

The Object of the present invention is an internal combustion engine to design with an exhaust gas turbocharger, one in an exhaust tract the internal combustion engine arranged closing body a locking device, which a targeted influence allowed on the positioning of the closing body, positioned in the exhaust tract in a closed position is that the closing body in an open position completely from a free flow cross-section is removable.

This object is achieved with an internal combustion engine with the features of claim 1. The dependent claims give appropriate weiterzubil on.

The inventive internal combustion engine with a Exhaust gas turbocharger has a closing body, which in the closed position in the exhaust pipe is positioned between that of the closing body covered flow area and a longitudinal axis the exhaust pipe formed a closing angle α is which is smaller than 90 °. This means that the Closing body in the closed position not, as usual horizontally to the longitudinal axis in the free Flow cross section is positioned, but opposite the longitudinal axis is arranged inclined in the exhaust pipe. In this case, the closing body is in the closed position arranged inclined so that in the open position of the closing body, the free flow cross-section is completely released. Ideally, the Closing angle α the maximum possible Movement angle β, which between the two stop positions is formed, whereby a maximum possible number of Intermediate positions is usable.

Of the Advantage of this invention is the fact that the closing body in a position in which the free flow cross section should be fully open, completely can be removed from the free flow cross-section and thus not as a flow obstacle in the free flow cross-section in Appearance occurs. This is a significant increase in performance the exhaust gas turbocharger realized. Likewise, a smaller Exhaust gas turbochargers are used because the the performance of the exhaust gas turbocharger influencing flow losses no longer over the size of the exhaust gas turbocharger be compensated have to.

In In one embodiment, the closing body has a Circular diameter, which is a diameter of the flow area equivalent. A free, arranged perpendicular to the longitudinal axis of the exhaust pipe Flow cross-section of the exhaust pipe is elliptical formed, wherein a largest ellipse diameter corresponds to the circle diameter and a smallest ellipse diameter the relation KED = sinα · DS follows. Through this Design of the free flow cross-section is thus everyone commercially available, generally circular shaped closing body can be used, so cost-effective usually installed closing devices in the form of wastegate valves can still be used.

In In another embodiment, the exhaust gas tract has a further exhaust gas line on which upstream of the closing body of the Exhaust pipe is positioned branching, so that the exhaust gas guide section with the help of the closing body is bypassable and not from out of the engine exhaust gas is charged.

In a further embodiment is downstream of the branch in the other Exhaust pipe another exhaust gas guide section of a arranged further exhaust gas turbocharger, so that one with the aid of the closing device controllable operation of the two exhaust gas turbochargers is possible.

Further Advantages and expedient designs The invention are the claims, the description of the figures and to take the drawings. Showing:

1 a schematic representation of an internal combustion engine according to the invention with an exhaust gas turbocharger and another exhaust gas turbocharger,

2 in a longitudinal section an exhaust pipe of an exhaust tract of the internal combustion engine gem. 1 with a closing device in a closed position,

3 in a longitudinal section, the exhaust pipe with the closing device in an open position,

4 in a sectional view a cross section through the exhaust pipe acc. 3 along the section line AA and

5 in a sectional view a cross section through the exhaust pipe acc. 3 along the section line BB.

In The figures are all the same or equivalent components with provided the same reference numerals.

In the 1 illustrated internal combustion engine 1 has a fresh air line 2 and an exhaust tract 3 on. During operation, the internal combustion engine sucks 1 over the fresh air line 2 Combustion air, which after a combustion of fuel in the internal combustion engine 1 as exhaust gas over the exhaust tract 3 is dissipated.

The fresh air line 2 has a charge air line 4 on which at their the internal combustion engine 1 facing arranged end to the internal combustion engine 1 connected is. Upstream of the internal combustion engine 1 is suitably in the charge air line 4 a charge air cooler 5 arranged for cooling sucked combustion air.

The exhaust tract 3 has an exhaust pipe 6 , at whose from the internal combustion engine 1 facing away from the end exhaust aftertreatment an exhaust aftertreatment system 7 arranged, which is designed in the form of a soot filter and / or catalyst and / or SCR system.

Furthermore, the internal combustion engine 1 a control and control unit 8th assigned to the regulation and control of numerous functions. About the control unit 8th In particular, the fuel supply is adjustable.

The internal combustion engine 1 is an exhaust gas turbocharger 9 as well as another exhaust gas turbocharger 10 assigned. The turbocharger 9 and the further exhaust gas turbocharger 10 have a housing 11 or another case 12 on, which has a flow-through exhaust gas guide section 13 or a further flow-through exhaust gas guide section 14 , a flow-through air guide section 15 or another air flow passage section that can be flowed through 16 and a storage section 17 or another storage section 18 include, wherein the air guide section 15 and the further air guiding section 16 each in the fresh air line 2 and the exhaust gas guide section 13 and the further exhaust gas guide section 14 each in the exhaust system 3 is arranged. The storage section 17 and the further storage section 18 are between the air guide section 15 and the exhaust gas guide section 13 or between the further air guide section 16 and the further exhaust gas guide section 14 positioned.

The turbocharger 9 or the further exhaust gas turbocharger 10 each have a in the housing 11 stored power tool 19 or in the other housing 12 stored another running gear 20 on which a compressor wheel 21 for sucking and compressing combustion air, a turbine wheel 22 for the expansion of exhaust gas and one the compressor wheel 21 with the turbine wheel 22 rotatably connecting shaft 23 with a rotation axis 24 or another compressor wheel 25 for sucking and compressing combustion air, another turbine wheel 26 for the expansion of exhaust gas and a further compressor wheel 25 with the other turbine wheel 26 rotatably connecting another wave 27 with another axis of rotation 28 includes. The compressor wheel 21 is in the air duct section 15 , the turbine wheel 22 is in the exhaust gas guide section 13 and the wave 23 is in the warehouse section 17 or the further compressor wheel 25 is in the further air guidance section 16 , the more turbine wheel 26 is in the further exhaust gas guide section 14 and the next wave 27 is in the further storage section 18 rotatably arranged. The exhaust gas guide section 13 is in the exhaust pipe 6 upstream of the exhaust aftertreatment system 7 positioned.

For the arrangement of the further exhaust gas guide section 14 in the exhaust tract 3 the internal combustion engine 1 is the exhaust tract 3 another exhaust pipe 29 associated, which upstream of the exhaust gas guide section 13 from the exhaust pipe 6 is arranged branching. The further air duct section 16 is upstream of the air guide section 15 in the intake tract 2 positioned throughflow.

In the 1 illustrated arrangement of the two exhaust gas turbocharger 9 . 10 allows parallel operation of the two turbochargers 9 . 10 , where the exhaust pipe 6 from the locking device 30 fully or partially open, leaving the turbine wheels 22 . 26 be acted upon by exhaust gas. Is the exhaust pipe 6 with the help of the locking device 30 closed, so only the other turbine wheel 26 acted upon by exhaust gas.

In another embodiment, not shown, the two exhaust gas turbochargers 9 . 10 arranged so that a serial operation of the two exhaust gas turbochargers 9 . 10 is possible. In this case, each exhaust gas guide section 13 . 14 in each case a bypass line of the exhaust tract 3 assigned, in which in each case the closing device 30 is positioned. Also, only one exhaust gas guide section, the exhaust gas guide section could 13 or the further exhaust gas guide section 14 be associated with a bypass line, in which the closing device 30 is positioned. Is the corresponding bypass line with the help of the locking device 30 closed, is the corresponding turbine wheel 22 . 26 acted upon by exhaust gas. On the other hand, is the corresponding bypass line with the help of the locking device 30 fully or partially open, the corresponding turbine wheel 22 . 26 not at all or only partially affected by the exhaust gas.

2 shows a longitudinal section of the exhaust pipe 6 with a locking device 30 , The locking device 30 includes a closing body 31 and an adjusting device 32 , The locking device 30 is designed in the form of a conventional wastegate valve. A positioning of the closing body 31 takes place with the help of an upstream of the internal combustion engine 1 in the charge air line 4 applied charge pressure. The locking device 30 is shown in a closed position, wherein the closing body 31 in a free flow cross section 33 the exhaust pipe 6 is positioned.

The closing body 31 is by means of a lever arm 34 the adjusting device 32 movable, the closing body 31 generally almost rigid with the lever arm 34 connected is. The lever arm 34 is about a rotation axis 35 the adjusting device 32 rotatable, wherein structurally conditioned between a first stop position of the lever arm 34 and a second stop position of the lever arm 34 a movement angle β of 60 ° is included. The movement angle β is manufacturer-dependent and typically varies in a range between about 45 ° and 65 °. As the closing body 31 with the lever arm 34 almost rigidly connected, points the closing body 31 the movement angle β of the lever arm 34 on.

In the 2 illustrated closed position of the locking device 30 corresponds to the first stop position of the lever arm 34 , For clarification is in 2 in addition the lever arm 34 dashed lines in the second stop position, wherein the second stop position of the opening position of the closing device 30 gem. 3 equivalent.

According to the invention, the closing body 31 in the closed position with respect to a longitudinal axis 36 the exhaust pipe 6 arranged inclined, such that between one of the closing body 31 covered flow area 37 and the longitudinal axis 36 a closing angle α is formed, which corresponds to the movement angle β. The flow area 37 , which from the closing body 31 is fully or partially closed or fully released, has a diameter D.

3 shows the closing body 31 in the opening position of the locking device 30 , So that the closing body 31 is disposed completely out of the flow in the open position, the exhaust pipe 6 , or the corresponding line section a recess 38 on which the locking device 30 is designed receptive. Ideally, the locking device 30 completely in the recess 38 arranged. It can also be parts of the locking device 30 outside the exhaust pipe 6 be arranged. However, it is important to pay attention to a seal of the flow against the environment.

Advantageously, a cross section of the exhaust pipe 6 through the flow area 37 circular shaped (s. 4 ), so ideally the free flow cross section 33 elliptical is formed (s. 5 ). A largest ellipse diameter GED corresponds to the circle diameter DS and a smallest ellipse diameter KED follows the relationship KED = sinα · DS.

For secure sealing of the flow area to be covered 37 is the closing body 31 formed larger at its outer periphery than the flow area to be covered 37 , leaving a predominantly circular bulge 39 in the area of the flow area to be covered 37 necessary is. Because this bulge 39 relatively small compared to the free flow area 33 can be held, here are open flow cross-section 33 possibly occurring flow irregularities negligible.

QUOTES INCLUDE IN THE DESCRIPTION

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Cited patent literature

• - JP 02153226 A1 [0007]

Claims (5)

Internal combustion engine with an exhaust gas turbocharger, and an exhaust tract ( 3 ), which an exhaust pipe ( 6 ) with a longitudinal axis ( 36 ), wherein a flow-through exhaust gas guide section ( 13 ) of the exhaust gas turbocharger ( 9 ) in the exhaust pipe ( 6 ) is arranged, and with a closing device ( 30 ), which has a closing body ( 31 ) and a lever arm ( 34 ) having a maximum travel angle (β) which is smaller than 90 °, wherein the closing body ( 31 ) upstream of the exhaust gas guide section ( 13 ) within the exhaust pipe ( 6 ) a closure position is arranged to be ingestible, in which the closing body ( 31 ) a flow area ( 37 ) is closable, characterized in that the closing body ( 31 ) in the closed position so in the exhaust pipe ( 6 ) is positioned between that of the closing body ( 31 ) covered flow area ( 37 ) and the longitudinal axis ( 36 ), a closing angle (α) is formed, which is smaller than 90 °. Internal combustion engine according to claim 1, characterized that the closing angle (α) the maximum travel angle (β) corresponds. Internal combustion engine according to claim 1 or 2, characterized in that the closing body ( 31 ) has a circle diameter (DS), which corresponds to a diameter (D) of the flow area to be covered, and a free, perpendicular to the longitudinal axis (DS) 36 ) positioned flow cross-section ( 33 ) of the exhaust pipe ( 6 ) is elliptical in shape, with a largest ellipse diameter (GED) corresponding to the circle diameter (DS) and a smallest ellipse diameter (KED) of the relationship KED = sinα · DS follows. Internal combustion engine according to one of claims 1 to 3, characterized in that the exhaust gas tract ( 3 ) another exhaust pipe ( 29 ), which upstream of the closing device ( 30 ) from the exhaust pipe ( 6 ) is branched off. Internal combustion engine according to claim 4, characterized in that downstream of the branch in the further exhaust pipe ( 29 ) a further exhaust gas guide section ( 14 ) of another exhaust gas turbocharger ( 10 ) is arranged.