DE102006024783A1 - Two-stage exhaust gas turbocharger for an internal combustion engine has an exhaust gas manifold and a high-pressure turbine in series in an exhaust gas' direction of flow - Google Patents

Abstract

Two-stage exhaust-gas turbocharger arrangement (1) for an internal combustion engine with an exhaust manifold (2) and with a high-pressure turbine arranged in series in the flow direction of an exhaust gas in a high-pressure turbine housing and a low-pressure turbine in a low-pressure turbine housing (3), wherein a bypass (5) closable by a throttle element (4) is provided ) is provided, which connects the exhaust manifold (2) and the low-pressure turbine housing (3) in the flow direction of the exhaust gas before the low-pressure turbine exhaust gas leading together, wherein the throttle body (4) in the direction of a valve stem (4a) push-movable poppet valve with a closure plate (4b) ,
Due to the inventive design flow losses of the exhaust gas are reduced.

Description

The The invention relates to a two-stage exhaust gas turbocharger arrangement with the features of the preamble of claim 1.

It starts from the German publication DE 102 30 934 A1 out. In this a two-stage, switchable exhaust gas turbocharger assembly for an internal combustion engine is described. The exhaust-gas turbocharger arrangement comprises a high-pressure supercharger close to the engine with a high-pressure turbine which is exhaust-connected to an exhaust gas collector of the internal combustion engine and with which a low-pressure turbine of a low-pressure supercharger is arranged in series. Each turbine are each assigned a controllable bypass, a low pressure bypass and a high pressure bypass, wherein the high pressure bypass is formed in a known manner with a wastegate valve. This wastegate valve is a flap valve known in the art.

specially in the transition area, in which both turbochargers make a significant contribution to the generation of the Have to afford boost pressure, is replaced by the o. g. Flap arrangement the existing exhaust energy not optimally used. The usable speed range of the internal combustion engine is restricted. The quality determining "spread" between the interpretation the high pressure and Low pressure level can not be optimally designed. This comes it either to Anfahrschwächen in the lower speed range, the so-called torque hole or a smaller one Maximum power of the internal combustion engine.

task The present invention is to show a measure with which o. g. Disadvantages are avoided.

These The object is achieved by the features in the characterizing part of the claim 1 solved.

By the embodiment of the invention will directed the velocity energy of the exhaust gas of the low-pressure turbine, with the least possible losses fed.

By the embodiment according to claim 2 can be in the fully open case the throttle body of the shutter in the exhaust manifold "sunk", so that the full exhaust gas mass flow without hindrance to the low-pressure turbine is directed. this leads to advantageously to a significantly improved rated power the internal combustion engine.

By the embodiment according to the claims 3 and 4 it is possible directing the exhaust gas even more directionally to the low-pressure turbine. hereby the performance of the internal combustion engine is increased again.

With the embodiment according to claim 5, the tightness of the throttle body is ensured.

in the The following is the invention with reference to two preferred embodiments closer in two figures explained.

1 shows a section through a first inventively designed two-stage exhaust gas turbocharger assembly.

2 shows the same section through a second inventively designed two-stage exhaust gas turbocharger assembly.

1 shows a section through an inventively designed exhaust gas turbocharger assembly 1 , The exhaust gas turbocharger arrangement 1 is for an internal combustion engine, not shown, with an exhaust manifold 2 intended. In the flow direction of an exhaust gas are geodetically above the exhaust manifold 2 arranged, not shown high-pressure turbine with a high-pressure turbine housing, not shown, and a geodetic down to the exhaust manifold 2 arranged, also not shown, low-pressure turbine in a low-pressure turbine housing 3 connected in series. It is one of a throttle body 4 lockable bypass 5 provided the exhaust manifold 2 and the low pressure turbine housing 3 in the flow direction of the exhaust gas in front of the low-pressure turbine exhaust gas leading together. On the functioning of the two-stage exhaust gas turbocharger 1 is expressly to the German patent application DE 102 30 934 A1 pointed.

According to the invention, the throttle body 4 one in the direction of a valve stem 4a slide-movable poppet valve with a closure plate 4b , Under locker 4b is any kind of significant cross-sectional widening of the valve stem 4a Understood. The throttle body 4 is from an actuator 6 sliding in the direction of the valve stem 4a actuated. In the present embodiment, the throttle body is located 4 in a closed position. The sealer 4b closes the bypass with an unspecified numbered sealing surface 5 , To the bypass 5 to open, the throttle body 4 from the actuator 6 moved in the direction of an arrow.

Radial around the valve stem 4a has the exhaust manifold 2 on the exhaust side a recess 2 ' on, in the full-opening case of the throttle body 4 the shutter 4b largely sunk. By this measure, the flow losses of the exhaust gas are minimized, whereby a maximum power for the internal combustion engine is achieved. For further performance enhancement, the sealer 4b on the low pressure turbine side facing a raised area 4c on, which is designed as a flow guide. Because the exhaust gas in the exhaust manifold 2 from at least two sides in the direction throttle body 4 flows, the raised region may for example be formed rotationally symmetrical or cutting-shaped, so that a flow direction of the exhaust gas from the raised area 4c in the direction of the bypass 5 is distracted. When the throttle body 4 is opened, the exhaust gas flows from the cylinders of the internal combustion engine through the exhaust manifold 2 continue through the bypass 5 directly into a spiral low-pressure turbine inlet 7 in the low-pressure turbine housing 3 ,

The inventive design of the two-stage switchable exhaust gas turbocharger arrangement, the exhaust gas energy is used optimally. The speed energy of the exhaust gas is directed by the embodiment of the invention directly the low-pressure turbine and fed with the lowest possible losses. This is supported by the flow-optimized design of the closure plate 4b , The ambient geometry and the occluder 4b are tuned so that the energy of the bypass exhaust gas flow is optimally utilized. In the full opening case of the throttle body 4 may be the occluder 4b in a recess 2 ' in the exhaust manifold 2 be sunk so that the full exhaust gas mass flow is passed without hindrance to the low-pressure turbine. As a result, the rated power of the internal combustion engine is substantially improved.

2 shows the same cut as 1 by a second inventively designed two-stage exhaust gas turbocharger assembly 1 , The same reference numbers apply to the same components as in 1 ,

The difference to 1 exists only in the geometric configuration of the closure plate 4b of the throttle body 4 , This is formed onion-shaped in the second embodiment, ie the closure plate 4b is flow optimized in a special way. An unnumbered sealing surface is radially on the outer circumference of the Verschlusstellers 4b arranged. In order to fully exploit the fluidic advantages, is also the recess 2 ' in the exhaust manifold 2 to the onion shape of the occluder 4b customized. In the full opening case of the throttle body 4 can thus the shutter, as in the first embodiment in the recess 2 ' the exhaust manifold 2 be sunk, so that in this embodiment, the full exhaust gas mass flow is passed without hindrance to the low-pressure turbine for improved rated power of the internal combustion engine. Thus, also in this second embodiment, the exhaust gas energy of the bypass exhaust gas flow is optimally utilized. In addition, the occluder can 4b form an optimal nozzle shape with its environment, such. As a Laval nozzle, for supercritical pressure conditions.

1

Turbocharger arrangement

2

exhaust manifold

2 '

recess

3

Low-pressure turbine case

4

throttle member

4a

valve stem

4b

closure plate

4c

sublime Area

5

bypass

6

locking device

7

Low-pressure turbine inlet

Claims (5)

Two-stage turbocharger arrangement ( 1 ) for an internal combustion engine with an exhaust manifold ( 2 ) and with a high-pressure turbine arranged in series in the flow direction of an exhaust gas in a high-pressure turbine housing and a low-pressure turbine in a low-pressure turbine housing ( 3 ), one of a throttle body ( 4 ) lockable bypass ( 5 ) is provided, the exhaust manifold ( 2 ) and the low-pressure turbine housing ( 3 ) in the flow direction of the exhaust gas in front of the low-pressure turbine exhaust gas leading together, characterized in that the throttle body ( 4 ) in the direction of a valve stem ( 4a ) slide-movable poppet valve with a closure plate ( 4b ). Two-stage turbocharger arrangement according to claim 1, characterized in that the exhaust side in the exhaust manifold ( 2 ) one coaxial with the valve stem ( 4a ) arranged recess ( 2 ' ) for accommodating the obturator ( 4b ) with the throttle body open ( 4 ) is provided. A two-stage exhaust gas turbocharger assembly according to claim 1 or 2, wherein the exhaust gas from at least two sides of the exhaust manifold ( 2 ) in the bypass ( 5 ) flows, characterized in that the closure plate ( 4b ) low pressure turbine side a raised area ( 4c ) having. Two-stage turbocharger arrangement according to claim 3, characterized in that the raised area ( 4c ) is formed as a flow guide. Two-stage turbocharger arrangement according to one of the aforementioned claims, characterized in that for the throttle body ( 4 ) in the exhaust manifold ( 2 ) or in the low pressure turbine housing ( 3 ) A sealing surface is provided.