Exhaust aftertreatment group

Abstract

Exhaust aftertreatment group (1) comprising the following: a main exhaust pipe (1.2), a branch line (1.3) which begins at a branch connection (1.3a) on the main exhaust gas line (1.2) and which opens into the main exhaust gas line (1.2) downstream of the branch connection (1.3a) at a branch outlet (1.3b), an exhaust gas catalyst (2) which is arranged in the branch line (1.3), and at least one exhaust valve (1.4, 1.6) with a mechanical drive (1.7) for moving a valve body (1.8), wherein the at least one exhaust valve (1.4, 1.6) has the following: a first exhaust valve (1.4) which is arranged downstream of the exhaust catalyst (2) in the branch line (1.3); and a second exhaust gas valve (1.6) which is arranged in the main exhaust gas line (1.2) downstream of the branch connection (1.3a) and upstream of the branch outlet (1.3b), wherein the first exhaust valve (1.4) and the second exhaust valve (1.6) are arranged opposite each other in parallel sections of the main exhaust pipe (1.2) and the branch pipe (1.3); wherein the actuator (1.7) is designed as a common actuator (1.7) for the first exhaust valve (1.4) and the second exhaust valve (1.6); wherein at least one exhaust valve (1.4, 1.6) is equipped with a gearbox (1.7a) for different control of the first and second exhaust valves (1.4, 1.6), and where only the first exhaust valve (1.4) or the second exhaust valve (1.6) has a gearbox (1.7a).

Description

[0001] The invention relates to an exhaust gas aftertreatment group with a main exhaust gas line, with a branch line which begins on the main exhaust gas line at a branch connection and opens downstream of the branch connection in the main exhaust gas line at a branch opening, wherein an exhaust gas catalyst is provided in the branch line and wherein an exhaust gas valve is provided with a mechanical drive for moving a valve body, via which an exhaust gas volume flow in the branch line or in the main exhaust gas line can be changed.

[0002] An exhaust aftertreatment system is already known from US Pat. No. 5,377,486 A, comprising a main exhaust line containing a catalyst and a bypass for the catalyst. Both the main exhaust line and the bypass have an exhaust valve.

[0003] Furthermore, EP 0 808 999 A1 discloses a control of a purification device for exhaust gases, wherein an exhaust gas control valve including a temperature sensor is connected to an exhaust manifold of an internal combustion engine of a motor vehicle.

[0004] In addition, DE 14 76 508 C shows an arrangement for exhaust gas detoxification in internal combustion engines.

[0005] US 4 404 804 A discloses an internal combustion engine with a turbocharger and a catalytic exhaust gas purification device arranged downstream of the exhaust turbine.

[0006] US 2007 / 0 272 480 A1 teaches an exhaust system of an internal combustion engine, wherein a single valve element is provided to select the connection between one of two flow channels forming an exhaust gas flow channel and to continuously provide a flow channel area of ​​the selected one of the two flow channels.

[0007] Furthermore, EP 3 575 566 A1 discloses an exhaust gas purification device with two backflow prevention plates. EP 1 355 049 A2 discloses a device and a method for controlling exhaust emissions from an internal combustion engine. WO 2020 / 260 041 A1 teaches an exhaust aftertreatment system for an internal combustion engine with an exhaust gas catalyst in a bypass line. DE 11 2006 001 296 B4 discloses an exhaust line for internal combustion engines. DE 10 2013 105 839 A1 discloses an actuating device and a flap device with such an actuating device for transmitting torque from a drive to two output shafts. EP 3 133 270 A1 discloses a device for controlling exhaust gases from an internal combustion engine, in particular when EGR (Exhaust Gas Recirculation) gas enters the intake tract of the engine. JP H04 - 279 712 A shows an exhaust gas purification device for internal combustion engines.

[0008] The present invention is directed to overcoming one or more of the problems or disadvantages associated with the prior art. In particular, the invention is based on the object of designing and arranging an exhaust gas aftertreatment group in such a way that a simplified structure is ensured.

[0009] The object of the present invention is achieved by an exhaust gas aftertreatment group according to claim 1. The subclaims relate to preferred embodiments of the invention.

[0010] The object is achieved according to the invention in that a first exhaust valve is arranged downstream of the exhaust gas catalytic converter in the branch line and in that a second exhaust valve is arranged in the main exhaust line downstream of the branch connection and upstream of the branch opening, wherein the first exhaust valve and the second exhaust valve are arranged opposite one another in parallel sections of the main exhaust line and the branch line; and wherein the drive is designed as a common drive for the first exhaust valve and the second exhaust valve. Furthermore, at least one exhaust valve is equipped with a gear for differently controlling the first and second exhaust valves. In this case, only the first exhaust valve or the second exhaust valve has a gear.

[0011] This ensures that only one drive is required for both exhaust pipe sections, which brings with it corresponding cost and assembly savings. The drive is a common motor which, via corresponding gear elements such as cables or rods, causes an actuating movement of both valves or both valve bodies. If the two valves are designed to oppositely rotate, i.e., closing to the right on the one hand and closing to the left on the other, then both valves can also be operated via a cable pull with a single motor shaft without further deflection. However, the motor, as a single drive, can be more easily mechanically connected to the two valves using pull or push rods. A common pneumatic drive, i.e., a positive or negative pressure source, can also be used.

[0012] Downstream of the branch connection and upstream of the branch outlet, both the main exhaust line and the branch line are valve- and throttle-free. If a throttle is not used in the branch line, there is only a single exhaust valve. No further exhaust valves are provided in either the main exhaust line or the branch line.

[0013] A throttle is a device for reducing the flow cross-section. The throttle ensures a cross-sectional narrowing of the exhaust gas flow cross-section by at least 10%.

[0014] If the first exhaust valve, or optionally a throttle in the branch line, is positioned downstream of the catalytic converter, the first exhaust valve is exposed to less hot exhaust gas. A downstream position can save space. An alternative, less stressed upstream position would ensure better or faster control of the exhaust valve. In some cases, the catalytic converter is exposed to less hot exhaust gas.

[0015] Furthermore, it may be advantageous if an exhaust turbine is provided in the main exhaust line downstream of the branch connection and upstream of the branch outlet, with the branch line forming a bypass of the exhaust turbine. The turbine can be used for energy generation (waste heat recovery).

[0016] It can also be advantageous if the second exhaust valve or (alternatively not claimed) a throttle in the main exhaust line is positioned upstream or downstream of the exhaust turbine. Downstream of the exhaust turbine, the second exhaust valve is exposed to less hot exhaust gas. A downstream position can save space. An upstream position ensures better or faster control of the exhaust valve. In some cases, the catalytic converter is exposed to less hot exhaust gas.

[0017] It can advantageously be provided that a main exhaust catalyst is located in the main exhaust line downstream of the branch outlet. This allows for a uniform design of the exhaust aftertreatment group. Positioning the catalyst downstream leads to more significant cooling of the exhaust gas upstream, which reduces the thermal stress on the catalyst during high-load operation. During partial-load operation, the main branch is closed by the second valve. The exhaust flow flows through the branch, enabling faster warm-up or earlier light-off of the catalyst located closer to the engine.

[0018] Of particular importance for the present invention may be if a particulate filter is provided in the main exhaust line downstream of the branch outlet and upstream of the main exhaust catalyst, or if the particulate filter is provided downstream of the main exhaust catalyst. This allows for a uniform design of the exhaust aftertreatment group.

[0019] It can also be advantageous if the gear is located between the drive and the valve body shaft. When two exhaust valves are used, only one exhaust valve is equipped with a gear, allowing different control or movement of the exhaust valves. The different movement refers to the adjustment path and / or the adjustment direction of the valve body. Thus, different movements of the two valves can be achieved with the same drive movement of the drive. While one valve is opened, the other can be closed synchronously (alternative not claimed).

[0020] Furthermore, it is advantageous that only the first exhaust valve or the second exhaust valve has a gear, as this facilitates the simple construction of the exhaust aftertreatment group.

[0021] In connection with the design and arrangement according to the invention, it can be advantageous if the exhaust valve, when closed, has a leakage of no more than 10% or no more than 5%. This protects the exhaust catalyst from excessive temperatures. Furthermore, the control accuracy of the exhaust valve is improved.

[0022] Further advantages and details of the invention are explained in the claims and the description and illustrated in the figures. They show: Fig. 1 to 9 schematic diagrams of various exhaust aftertreatment groups; Fig. 10a a schematic diagram of an exhaust valve and Fig. 10b a schematic diagram of an exhaust valve with gear.

[0023] An exhaust aftertreatment group 1 according to the Fig. 1-4 has a main exhaust line 1.2 and a branch line 1.3. An exhaust outlet 1.1 opens into the exhaust aftertreatment group 1. The branch line 1.3 begins at the main exhaust line 1.2 at a branch connection 1.3a and opens downstream of the branch connection into the main exhaust line 1.2 at a branch opening 1.3b. An exhaust gas catalyst 2 is provided in the branch line 1.3. Furthermore, two exhaust valves 1.4, 1.6 are provided, each with at least one valve body 1.8, via which an exhaust gas volume flow in the branch line 1.3 and in the main exhaust line 1.2 can be varied. The first exhaust valve 1.4 is located in the branch line 1.3, and the second exhaust valve 1.6 is located in the main exhaust line 1.2, downstream of the branch connection 1.3a and upstream of the branch opening 1.3b. Both exhaust valves 1.4 and 1.6 share a common drive 1.7 for moving a valve body 1.8.

[0024] A main exhaust catalyst 6 is provided in the main exhaust line 1.2 downstream of the branch opening 1.3b. In addition, a particulate filter 7 is provided in the main exhaust line 1.2 downstream of the branch opening 1.3b and downstream of the main exhaust catalyst 6 (see example Fig. 1-4). This order is provided for each embodiment. Alternatively, and regardless of the valve architecture, the particulate filter 7 can also be placed upstream of the main exhaust gas catalyst 6 (see example Fig. 5-9).

[0025] After Fig. 1 and Fig. 2, the first exhaust valve 1.4 is placed upstream of the exhaust catalyst 2. The first exhaust valve 1.4 is placed adjacent to the second exhaust valve 1.6 in transverse sections of the line 1.2, 1.3. Fig. 2 and Fig. 4, the first exhaust valve 1.4 and the second exhaust valve 1.6 are placed opposite each other in parallel sections of the line 1.2, 1.3. While in Fig. 1 the valve pairing 1.4, 1.6 is arranged maximally upstream, it is Fig. 3 arranged maximally downstream.

[0026] According to Fig. 5 and Fig. 7, as an alternative to one of the exhaust valves, here as an alternative to the first exhaust valve 1.4, a (not claimed) drive-free throttle 1.5 is provided in the branch line 1.3. The (second) exhaust valve 1.6, which has the drive 1.7, is provided in the main exhaust line 1.2. The positioning of the exhaust valve-throttle pairing of the embodiments according to Fig. 5 and Fig. 7 corresponds to the valve pairing according to Fig. 1 and Fig. 3.

[0027] After Fig. 6 and Fig. 8, a 3 / 2-way valve 1.4 is provided as an alternative to the respective valve pairing or alternative to the respective valve-throttle pairing, which is controllable via the actuator 1.7. The 3 / 2-way valve 1.4 forms the branch connection 1.3a or the branch opening 1.3b.

[0028] After Fig. 9, an exhaust gas turbine 5 is provided in the main exhaust line 1.2 downstream of the branch connection 1.3a and upstream of the branch opening 1.3b. The branch line 1.3 is designed as a bypass of the exhaust gas turbine 5.

[0029] Integration of an exhaust gas turbine 5 in the main exhaust gas line 1.2 downstream of the branch connection 1.3a and upstream of the branch opening 1.3b is also for all embodiments according to the Fig. 1 to Fig. 8 is provided.

[0030] The respective exhaust valve 1.4, 1.6 has Fig. 10a or Fig. 10b has a valve body 1.8, which is mechanically coupled to the drive 1.7 via a valve body shaft 1.9. The drive 1.7 allows the valve body 1.8 to be moved in the directions of rotation indicated by the arrows. The other exhaust valve 1.6, 1.4, shown here in dashed lines, is moved by the same drive 1.7.

[0031] After Fig. 10b, a gear 1.7a is also provided between the drive 1.7 and the valve body 1.9 of the exhaust valve 1.6. No gear 1.7a is provided between the drive 1.7 and the exhaust valve 1.4. The drive acts directly on the exhaust valve 1.4 or its valve body 1.9. List of reference symbols 1 exhaust aftertreatment group 1.1 Exhaust outlet 1.2 Main exhaust line 1.3 Branch line, branch, bypass 1.3a Branch connection 1.3b Branch mouth 1.4 first exhaust valve, 3-2-way valve, branch connection, branch outlet 1.5 Throttle 1.6 second exhaust valve 1.6a exhaust valve 1.7 Drive for exhaust valve 1.7a gearbox 1.8 Valve body 1.9 Valve body 2 three-way catalytic converter, exhaust gas catalytic converter 5 exhaust turbine 6 Three-way catalyst, main exhaust catalyst 7 Particle filter, main exhaust particulate filter

Claims

[1] Exhaust aftertreatment group (1) comprising: a main exhaust pipe (1.2), a branch line (1.3) which begins at a branch connection (1.3a) on the main exhaust line (1.2) and which opens into the main exhaust line (1.2) at a branch opening (1.3b) downstream of the branch connection (1.3a), an exhaust gas catalyst (2) arranged in the branch line (1.3), and at least one exhaust valve (1.4, 1.6) with a mechanical drive (1.7) for moving a valve body (1.8), wherein the at least one exhaust valve (1.4, 1.6) comprises: a first exhaust valve (1.4) arranged downstream of the exhaust gas catalyst (2) in the branch line (1.3); and a second exhaust valve (1.6) arranged in the main exhaust line (1.2) downstream of the branch connection (1.3a) and upstream of the branch opening (1.3b), wherein the first exhaust valve (1.4) and the second exhaust valve (1.6) are arranged opposite each other in parallel sections of the main exhaust line (1.2) and the branch line (1.3); wherein the drive (1.7) is designed as a common drive (1.7) for the first exhaust valve (1.4) and the second exhaust valve (1.6); wherein at least one exhaust valve (1.4, 1.6) is equipped with a gear (1.7a) for a different control of the first and the second exhaust valve (1.4, 1.6), and wherein only the first exhaust valve (1.4) or the second exhaust valve (1.6) has a gear (1.7a). [2] Exhaust aftertreatment group (1) according to claim 1, characterized by that an exhaust gas turbine (5) is provided in the main exhaust gas line (1.2) downstream of the branch connection (1.3a, 1.4) and upstream of the branch opening (1.3b, 1.4), wherein the branch line (1.3) forms a bypass of the exhaust gas turbine (5). [3] Exhaust aftertreatment group (1) according to claim 2, characterized by that the second exhaust valve (1.6) is placed in the main exhaust line (1.2) upstream or downstream of the exhaust turbine (5). [4] Exhaust aftertreatment group (1) according to one of the preceding claims, characterized by that a main exhaust gas catalyst (6) is provided in the main exhaust gas line (1.2) downstream of the branch opening (1.3b, 1.4). [5] Exhaust gas aftertreatment group (1) according to one of the preceding claims, characterized by that a particle filter (7) is provided in the main exhaust line (1.2) downstream of the branch opening (1.3b, 1.4) and upstream of the main exhaust gas catalyst (6) or that the particle filter (7) is provided downstream of the main exhaust gas catalyst (6). [6] Exhaust aftertreatment group (1) according to one of the preceding claims, characterized by that the gear (1.7a) is provided between the drive (1.7) and the valve body (1.9). [7] Exhaust aftertreatment group (1) according to one of the preceding claims, characterized by that the exhaust valve (1.6) has a leakage of a maximum of 10% or a maximum of 5% when closed.

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