DE102021006119B3 - Secondary air supply for an exhaust device of an internal combustion engine, exhaust device, internal combustion engine and motor vehicle - Google Patents

Abstract

The invention relates to a secondary air supply (14) for an exhaust device (12) of an internal combustion engine (10) of a motor vehicle (36), having at least one supply duct (20) for air (22), the supply duct (20) having an outlet opening (24) in an outlet channel (26) of the exhaust device (12), wherein between the feed channel (20) and the outlet opening (24) a geometric provision (28) is formed as an air guiding element, so that the supplied air (22) in the direction of an exhaust gas flow ( 30) is guided in the outlet channel (26). The invention also relates to an exhaust device (12), an internal combustion engine (10) and a motor vehicle (36).

Description

The invention relates to a secondary air supply for an exhaust device of an internal combustion engine of a motor vehicle according to the preamble of patent claim 1. The invention also relates to an exhaust device, an internal combustion engine and a motor vehicle.

It is already known that in combustion engines it is necessary to reach the working temperature in the exhaust aftertreatment as quickly as possible so that the corresponding emissions are below the legally permitted values. It is already provided that, for example in Otto engines, a secondary air injection is arranged on the outlet side. If the internal combustion engine is started "cold", air is blown in on the outlet side. The incoming and convertible secondary air injection is essentially dependent on the performance of a corresponding secondary air pump and the power output of the engine.

The DE 100 03 955 A1 discloses a secondary air supply for the exhaust ducts of four-cylinder internal combustion engines, which includes a secondary air main duct and a distribution duct and which is characterized in that, with a two-flow design of the exhaust pipe, a central secondary air main duct is formed by a recess within the cylinder head wall and with a groove-shaped indentation in the flange surface for the connection the cylinder head side wall surface forming the exhaust pipe and in turn is connected to the distributor duct communicating with blow-in planks.

The DE 10 2018 216 278 A1 describes an internal combustion engine with an outlet duct arrangement with at least one outlet duct emanating from a combustion chamber and at least one secondary air duct opening into the outlet duct, with at least one outlet duct having a duct wall forming a pocket which is open towards at least one outlet duct and into which the secondary air duct opens, the pocket passing through a bulge in the duct wall is formed by at least one outlet duct, with at least one tear-off edge being formed between the bulge and the upstream duct wall of at least one outlet duct.

According to the EP 3 388 647 A1 there is provided a secondary air introduction device configured to introduce air into an exhaust port provided in a cylinder head of an engine by using negative pressure in the exhaust port. A reverse flow restricting member is provided between a reed valve and the outlet port in an air intake duct, and includes a plate portion intersecting with an extending direction of the air intake duct. The plate part has an air passage area in which the air flowing through the air intake duct from an air intake unit to the exhaust port can pass, and a reverse flow blocking area in which exhaust air flowing in a direction in which it directly collides with at least one valve body of the reed valve from exhaust air flowing back from the exhaust port through the air intake duct is shut off.

In the DE 199 44 010 A1 it is proposed that a secondary air supply passage connecting a reed valve chamber provided on a cylinder head cover and an exhaust gas passage of a crankcase is formed by a secondary air supply passage of a cylinder head, a secondary air supply passage of a cam holder and a secondary air passage of a cylinder head cover. The secondary air supply duct is formed perpendicularly to a gasket and the end is connected to the secondary exhaust air inlet part which is integrally formed with the core of the exhaust duct when the cylinder head is cast.

The object of the present invention is to create a secondary air supply, an exhaust gas device, an internal combustion engine and a motor vehicle, by means of which improved operation of the internal combustion engine can be implemented.

This object is achieved by a secondary air supply, an exhaust gas device, an internal combustion engine and by a motor vehicle according to the independent patent claims. Advantageous embodiments are specified in the dependent claims.

One aspect of the invention relates to a secondary air supply for an exhaust device of an internal combustion engine of a motor vehicle, with at least one supply channel for air, the supply channel opening with an outlet opening in an outlet channel of the exhaust device.

It is provided that between the supply duct and the outlet opening a geometric provision is formed as an air guiding element, so that the supplied air is directed in the direction of an exhaust gas flow in the outlet duct.

In particular, a targeted relief of the outlet opening, which can also be referred to as the inflow point, is thus realized by the geometric resetting. As a result, the working area with the same configuration of the secondary air supply of the internal combustion engine to be expanded. Alternatively, for example, the dimensions of the secondary air pump can be reduced. Furthermore, there is an improvement in the response behavior in the air injection, so that, for example, the full power can be called up immediately by a user of the motor vehicle.

In particular, the invention thus solves the problem that, compared to the prior art, the secondary air is sheared off at the outlet opening. The geometric provision now makes it possible for the secondary air to be sucked in by the corresponding exhaust gas flow, as a result of which the secondary air is guided more reliably and better into the exhaust port.

The geometric provision is designed like a trough. In particular, the supplied air can thus be reliably guided in the direction of the exhaust gas flow. Furthermore, this is a simple embodiment that can be easily produced.

Furthermore, the geometric reset is tapered in the direction of exhaust gas flow. As a result, the flow of exhaust gas can be reliably guided into the exhaust port and at the same time the supplied air can be sucked in via the narrowing. In particular, it is provided that the outlet opening is located at the tapered end of the geometric reset.

In a further advantageous embodiment, the geometric reset extends over a bend in the outlet channel. In particular, the geometric provision is thus elongate and also has the bend, so that the exhaust gas flow can be reliably guided within the outlet channel.

It is also advantageous if the outlet opening is formed behind the bend. In this way, the supplied air can be guided reliably in the direction of the exhaust gas flow. In particular, the performance of the secondary air supply can be increased as a result.

Furthermore, it has proven to be advantageous if the geometrical repositioning adapts to the bending. As a result, spatial utilization can be ensured, so that both the exhaust gas flow can be reliably guided and the supplied air can be reliably introduced into the exhaust gas flow.

It is also advantageous if a secondary pump is provided for actively feeding air into the outlet channel. In particular, the air is sucked in via the exhaust gas flow and at the same time actively pumped into the exhaust gas flow via the secondary pump, as a result of which an improved performance of the internal combustion engine can be accessed.

A further aspect of the invention relates to an exhaust gas device with a secondary air supply according to the preceding aspect. Furthermore, the invention also relates to an internal combustion engine with an exhaust gas device according to the preceding aspect. Furthermore, the invention also relates to a motor vehicle with an internal combustion engine according to the preceding aspect.

Advantageous configurations of the secondary air supply are to be regarded as advantageous configurations of the exhaust gas device, the internal combustion engine and the motor vehicle.

Further advantages, features and details of the invention result from the following description of preferred exemplary embodiments and from the drawings. The features and combinations of features mentioned above in the description and the features and combinations of features mentioned below in the description of the figures and/or shown alone in the figures can be used not only in the combination specified in each case, but also in other combinations or on their own, without going beyond the scope of the leave invention.

• 1 eine schematische Schnittansicht einer Ausführungsform einer Verbrennungskraftmaschine mit einer Ausführungsform einer Abgasvorrichtung mit einer Ausführungsform einer Sekundärluftzuführung;
• 2 eine weitere schematische Schnittansicht gemäß 1; und
• 3 eine schematische Perspektivansicht gemäß einer Ausführungsform einer Abgasvorrichtung.

show:

• 1 a schematic sectional view of an embodiment of an internal combustion engine with an embodiment of an exhaust device with an embodiment of a secondary air supply;
• 2 a further schematic sectional view according to FIG 1 ; and
• 3 a schematic perspective view according to an embodiment of an exhaust device.

Elements that are the same or have the same function are provided with the same reference symbols in the figures.

1 1 shows a schematic sectional view according to an embodiment of an internal combustion engine 10 for a motor vehicle 36 which is illustrated purely schematically. The internal combustion engine 10 has an exhaust gas device 12 . Furthermore, internal combustion engine 10 has a secondary air supply 14 . Furthermore, in particular a valve stem guide 16 and a valve seat 18 are shown.

In particular, it is provided that the secondary air supply 14 has at least one supply duct 20 for air 22 , the supply duct 20 opening with an outlet opening 24 into an outlet duct 26 of the exhaust gas device 12 .

It is provided that between the supply channel 20 and the outlet opening 24 a geometric provision 28 is formed as an air guiding element, so that the supplied air 22 is directed in the direction of an exhaust gas flow 30 . In the present example, the exhaust gas flow 30 proceeds from the valve seat 18 into the outlet channel 26.

In particular, it is shown that the geometric provision 28 is designed in the manner of a channel. Furthermore, it is shown that the geometric reset 28 tapers in the direction of the exhaust gas flow 30 .

The 1 FIG. 12 further shows that the geometric reset 28 extends across a bend 32 in the exhaust passage 26, with the exhaust port 24 further being formed behind the bend 32. FIG. Furthermore, the geometric provision 28 nestles against the bend 32 .

Furthermore, it can be provided that a secondary air pump 34 is provided for actively supplying air 22 into the outlet channel 26 . The secondary air pump 34 is shown purely schematically in the present case.

In particular, the 1 that a targeted relief of the outflow opening 24 is provided by the geometric provision 28. As a result, the operating range of internal combustion engine 10 can be expanded with the same hardware or there is a possibility of reducing the size of secondary air pump 34. Furthermore, the response behavior of the air injection improves, as a result of which the full power of internal combustion engine 10 in particular can be called up immediately by a user.

2 shows a further schematic sectional view of internal combustion engine 10. In the present case, in particular, a plan view of geometric reset 28 is shown. In particular, the geometric provision 28 allows the air 22 to be actively sucked in with the exhaust gas flow 30 .

3 shows a schematic perspective view according to an embodiment of the exhaust gas device 12. In the present case, in particular, a respective plan view of the geometric provisions 28 with the outlet channels 26 is shown.

In particular, the 1 until 3 an extension of the working range of an air injection by the geometric provision 28 as a chute to improve the injected air flow.

Reference List

10

internal combustion engine

12

exhaust device

14

secondary air intake

16

valve stem guides

18

valve seat

20

feed channel

22

Air

24

exhaust port

26

exhaust port

28

geometric default

30

exhaust flow

32

bend

34

secondary air pump

36

motor vehicle

Claims (8)

Secondary air supply (14) for an exhaust device (12) of an internal combustion engine (10) of a motor vehicle (36), with at least one supply duct (20) for air (22), the supply duct (20) having an outlet opening (24) in an outlet duct ( 26) of the exhaust gas device (12), with a geometric recess (28) being formed as an air guiding element between the supply duct (20) and the outlet opening (24), so that the supplied air (22) flows in the direction of an exhaust gas flow (30) in the outlet duct (26), the geometric provision (28) being designed like a trough, characterized in that the geometric provision (28) tapers in the direction of the exhaust gas flow (30). Secondary air supply (14) after claim 1 , characterized in that the geometrical provision (28) extends over a bend (32) in the outlet channel (26). Secondary air supply (14) after claim 2 , characterized in that the outlet opening (24) is formed behind the bend (32). Secondary air supply (14) after claim 2 or 3 , characterized in that the geometric provision (28) hugs the bend (32). Secondary air supply (14) according to one of the preceding claims, characterized in that a secondary air pump (34) is provided for actively supplying air (22) into the outlet duct (26). Exhaust device (12) with a secondary air supply (14) according to one of Claims 1 until 5 . Internal combustion engine (10) with an exhaust device (12). claim 6 . Motor vehicle (36) with an internal combustion engine (10). claim 7 .

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