WO2012110163A1

WO2012110163A1 - Turbocharger

Info

Publication number: WO2012110163A1
Application number: PCT/EP2011/074247
Authority: WO
Inventors: Michael Baeuerle; Lukas GONO; Reiner Schweinfurth; Michael Nau; David TRTEK; Holger Knesch; Jan Vesely
Original assignee: Robert Bosch Gmbh
Priority date: 2011-02-14
Filing date: 2011-12-29
Publication date: 2012-08-23
Also published as: DE102011004027A1; EP2676019A1

Abstract

The invention relates to a turbocharger (1), in particular for a motor vehicle, comprising at least one turbine (2) with which an actuatable bypass valve (8) is associated, and an actuator (19) which is connected to a valve element (9) of the bypass valve (8) by means of a connecting rod (14), the valve element (9) being movable about a valve axis (12). According to the invention, the connecting rod (14) extends at least substantially perpendicular to the main axis (15) of the turbocharger (1), while the valve axis (12) extends at least substantially parallel thereto.

Description

description

title

The invention relates to an exhaust gas turbocharger, in particular for a motor vehicle, with at least one turbine, which is associated with an actuatable bypass valve, and with an actuator, which is connected by a coupling rod with a displaceable about a valve axis valve element of the bypass valve. State of the art

Exhaust gas turbochargers of the type mentioned are known from the prior art. In general, exhaust gas turbochargers serve to increase the performance of internal combustion engines. For this purpose, they have a compressor which is arranged in the intake tract in order to compress the fresh air supplied to the internal combustion engine, so that a higher degree of filling in the combustion chambers is achieved. The compressor is driven by a turbine which uses the energy of the exhaust gas produced by the internal combustion engine. Modern exhaust gas turbochargers include means that allow to influence the performance of the exhaust gas turbocharger. In particular, this includes a bypass assigned to the turbine.

Valve located in a bypass that connects, for example, a high pressure side of the turbine with a low pressure side of the turbine. By opening the bypass valve, the pressure on the high-pressure side of the turbine can thus be reduced, whereby the power of the turbine and thus also the performance of the compressor is reduced. Usually, the bypass valve is a

Assigned actuator which is connected by a coupling rod with a displaceable valve element of the bypass valve. By pressing the

Actuator that drives the coupling rod, the valve element

relocated to open or close the bypass.

Typically, the coupling rod is parallel to the main axis of the

Exhaust gas turbocharger, ie parallel to the axis of rotation of the compressor with the turbine aligned connecting shaft, while the valve axis about which the valve element is displaceable, perpendicular to the main axis. Due to the usual design of the bypass valve creates a non-linear force-displacement curve with high closing forces, which must be provided by the actuator. These depend on the displacement, degree of charge and others

Parameters to observe ever higher demands on the associated force-displacement integral. In combination with the achievable positioning time and the extreme space restriction around the exhaust gas turbocharger

Power densities required in existing ones

Space limitations not simply by a performance-enhancing

Enlargement of the actuator can be achieved.

Disclosure of the invention

The exhaust gas turbocharger according to the invention with the features of claim 1 has the advantage that a solution is offered, which takes advantage of the available space and yet meets the performance requirements. The exhaust gas turbocharger according to the invention is characterized in that the

Coupling rod at least substantially perpendicular and the valve axis are aligned at least substantially parallel to the main axis of the exhaust gas turbocharger. This arrangement of the coupling rod and the valve axis opens the possibility to position the actuator in a more advantageous position on the exhaust gas turbocharger. Especially by the vertical

Alignment of the coupling rod, the actuator is sufficient

spaced while maintaining the space requirements of the

Arrange the exhaust gas turbocharger so that maximum distances to be maintained by the actuator of, for example, air, exhaust or coolant lines leading and other elements of the engine can be met. In addition, the arrangement according to the invention is also advantageous for the power transmission and the design of the housing of the exhaust gas turbocharger and / or the turbine as a sheet metal construction. In contrast to the currently established cast manufacturing, the design as a sheet metal construction is less expensive and has advantages in terms of emission behavior, since it forms a smaller heat sink when heating a catalytic converter. Preferably, the actuator has an electromechanical or electromagnetic actuator. Due to the vertical orientation of the coupling rod, in particular the electromechanical servo motor can be arranged sufficiently far away from the exhaust gas turbocharger, so that sufficient cooling of the servomotor is ensured.

Preferably, the valve element is designed to open or close the bypass valve to the valve axis hinged. As a result, the particular plate-shaped valve element is folded onto the valve seat. For this purpose, the valve axis lies in or parallel to the plane in which the opening to be closed or the valve seat are located.

According to an alternative embodiment, it is preferably provided that the particular plate-shaped valve element for opening or closing the bypass valve is formed laterally pivotable about the valve axis. For this purpose, the valve axis is at least substantially perpendicular or more preferably obliquely, in particular at an angle between 80 ° and 5 °, preferably between 45 ° and 10 °, to the plane in which the

occlusive opening or the valve seat is located. By the lateral pivoting of the valve element lower actuating forces are necessary, since the valve element now, for example, not against the pressure force of

Exhaust gas flow is shifted.

Particularly preferably, the laterally pivotable valve element is tilted aligned with the pivoting plane. Due to the thus obtained inclined position of the valve element, in particular of the plate-shaped valve element, only one of the gas forces resulting partial force component acts on the

Pivoting mechanism, thereby reducing the required

Transmission forces is achieved. Appropriately, the valve seat is also tilted or aligned obliquely with respect to the pivot plane, so that in the closed state, the valve element rests tightly on the valve seat.

According to an advantageous development, it is provided that the laterally pivotable valve element is tilted about a valve longitudinal axis lying perpendicular to the valve axis. The valve longitudinal axis is in particular the Axle, which preferably extends from the valve axis perpendicular and forms the main longitudinal axis of the valve element. By tilting the valve element about this valve longitudinal axis is a particularly advantageous inclination or tilted position of the valve element with respect to the

Tilting level achieved. Conveniently, the valve seat is aligned accordingly, so that in an end pivotal position, the valve element rests sealingly on the valve seat.

It is preferably provided that the bypass valve is designed as a flat seat valve. This means that the valve element is substantially plate-shaped and cooperates with one of its end faces with a flat valve seat. Under a flat valve seat is here

For example, to understand a to be closed or to be released opening surrounding annular projection or axial projection having a flattened end face on which the

Valve element sealingly rests in the closed position of the bypass. The design as a flat seat valve, a cost-effective and reliable valve is used.

Preferably, the actuator further comprises a transmission gear, in particular gear transmission, which connects the servomotor with the coupling rod. By the transmission gear, a high speed of the servomotor is converted into a low speed and high torque, which is transmitted to the coupling rod to the bypass valve

or to relocate the valve element of the bypass valve for opening or closing. By the transmission gear, the required actuating forces, in particular closing forces of the bypass valve, can also be provided with a less powerful electromechanical actuator.

According to an advantageous embodiment of the invention it is provided that the transmission gear has three transmission axes, which are in a row or offset from each other. Conveniently, each of the transmission axes is associated with at least one gear, which meshes with at least one adjacent gear. Thus, a first transmission axis is formed by the output shaft of the electromechanical servo motor, on which a Input-side drive gear is arranged rotatably. This gear is engaged with a first idler gear on a second gear axis. On the second transmission axis, a third intermediate gear is further preferably arranged non-rotatably, which meshes with an arranged on the third transmission axis, output-side gear, wherein on the third transmission axis preferably a crank is arranged, with which the coupling rod is connected.

Particularly preferably, the three transmission axes are triangular to each other and / or on a radius, in particular with respect to the main axis of the

Exhaust gas turbocharger. As a result, a particularly compact arrangement of the transmission gear is ensured, in particular takes place while adapting the shape of the transmission gear to the shape of the exhaust gas turbocharger.

In the following, the invention will be explained in more detail with reference to the drawing. Show this

1 shows an exhaust gas turbocharger according to the prior art,

Figure 2 shows a first embodiment of an inventive

Exhaust gas turbocharger,

Figure 3 shows a second embodiment of the invention

Exhaust gas turbocharger,

4 shows an advantageous development in a detailed view,

5 shows a transmission gear of an actuator of the exhaust gas turbocharger and

Figure 6 shows an advantageous development of the transmission gear.

FIG. 1 shows a perspective partial sectional view of a

Exhaust gas turbocharger 1 for a motor vehicle. The exhaust gas turbocharger 1 comprises a turbine 2 and a compressor 3, which are operatively connected to each other. For this purpose, a turbine wheel 4 of the turbine 2 is rotatably mounted on a shaft 5, on which also a turbine wheel 6 of the compressor 3 is arranged rotationally fixed.

Exhaust gas turbochargers and their operation are generally known, so it will not be discussed in more detail here. The turbine 2 is also associated with a bypass 7, which is a bypass valve

8 and leads from the high pressure side of the turbine 2 to the low pressure side of the turbine 2. The valve element 9 is plate-shaped to form the bypass valve 8 as a flat seat valve 10, and rotatably connected to a valve shaft 1 1, which is rotatably held in the housing of the exhaust gas turbocharger 1. The valve shaft 1 1 forms a valve axis 12 about which the valve element 9 is displaceable. On the valve shaft 1 1, a lever 13 is further arranged non-rotatably, which is pivotally connected to a coupling rod 14. The

Coupling rod 14 is in turn connected at its other end with an actuator, not shown in Figure 1, which displaces the coupling rod 14 along its axis when actuated to actuate the bypass valve 8. The

Coupling rod is parallel to the shaft 5, which forms a main axis 15 of the exhaust gas turbocharger 1, arranged, while the valve axis 12th

or the valve shaft 1 1 substantially perpendicular to the

Main axis 15 are aligned. This results in high adjusting forces for actuating the bypass valve 8, which usually by means of an over- or

Vacuum box can be provided.

Figure 2 shows a preferred embodiment of the exhaust gas turbocharger 1, in which a more advantageous arrangement of coupling rod 14 and valve axis 12 has been selected. In contrast to exhaust gas turbochargers from the prior art, as in

2, the coupling rod 14 is oriented at least essentially perpendicular to the main axis 15, while the valve axis 12 lies at least substantially parallel to the main axis 15. The coupling rod 14 is connected to a crank 16 of a transmission gear 17, which of a

electromechanical actuator 18 is driven. On the exact design of the transmission 17 will be discussed later in more detail. Due to the advantageous arrangement of the coupling rod 14 and the valve axis 12 of the servomotor 18 is sufficiently spaced to the exhaust gas turbocharger 1 can be arranged, yet a compact design is guaranteed. Due to the vertical orientation of the coupling rod 14 to the main axis 15 of the Electric motor and the transmission gear 17, which together a

Forming actuator 19 of the exhaust gas turbocharger 1, laterally spaced from the exhaust gas turbocharger 1, so that in particular a protection of the servomotor 18 is ensured from the high temperatures of the exhaust gas turbocharger 1. The advantageous embodiment also has advantages in terms of the construction of the

Housing of the exhaust gas turbocharger 1 and in particular the turbine 2, since the turbine housing is now also manufacturable as a sheet metal construction, which leads to lower production costs and a lower total weight compared to conventional turbine housings, which are manufactured by a cast-manufacturing. In addition, the emission behavior is improved, since the turbine 2 forms a smaller heat sink, which is particularly advantageous in a heating operation for a catalyst of the motor vehicle. An appropriate design of the actuator 19 together with the coupling rod 14 can also be used for the adjustment of a variable turbine geometry - not shown here - so that there are packaging advantages through which

Use of the same components for different functions.

According to the illustrated exemplary embodiment in FIG. 2, the plate-shaped valve element 9 lies at least substantially in a plane which is aligned parallel to the valve axis 12. Accordingly it behaves with one of the

Valve element 9 to be closed valve seat 20, which in the

Exhaust gas turbocharger housing is formed. Due to the design as a flat seat valve 10, the plate-shaped valve element 9 is folded by actuation of the actuator 19 on the valve seat 20 or removed by this by unfolding.

As a result, an opening surrounded by the valve seat 20 is closed

or released, which is assigned to the bypass 7. The bypass valve 8 is thus aligned radially with respect to the main axis 15,

or the valve element 9 is folded substantially radially with respect to the main axis.

Figure 3 shows a preferred alternative embodiment of the exhaust gas turbocharger 1, wherein already known elements of Figure 2 are provided with the same reference numerals, so reference is made in this respect to the above description. In the following, only the differences will be discussed. The essential difference of the second embodiment according to Figure 3 is that the valve element 9 of the bypass valve 8 is not hinged to the valve seat 20, but is formed laterally pivotable. The valve element 9 is thus not opened, but laterally pushed over the valve seat 20 to release the bypass 7 or to close. The

Contact plane between the valve seat 20 and the plate-shaped valve element 9 is preferably slightly tilted to a vertical plane with respect to the valve axis 12. By actuating the actuator 19, the valve element 9 via the valve seat

20 pushed until they are aligned with each other, whereby the bypass 7 is completely closed. While in the previous one

Embodiment of the bypass 7 extends radially from the turbine housing, according to the second embodiment, the bypass 7 or at least its inlet opening is substantially aligned axially thereto. The embodiment according to FIG. 3 furthermore has the advantage that the actuating forces for closing the bypass valve 8 are lower, since in operation the pressure of the exhaust gas flowing to the turbine 2 forces the valve element 9 against the valve seat 20 and thereby the closing force generated by the actuator 19 supported.

Figure 4 shows a preferred embodiment of the exhaust gas turbocharger 1 according to the second embodiment of Figure 3. Figure 4 shows the bypass valve 8 in a side view. The dish-shaped valve element 9 is

preferably circular, so that it has a valve element axis 21. Preferably, as shown in Figure 4, the valve element axis 21 is aligned at an acute angle α to the valve axis 12, so that the

Valve element 9 is tilted to the valve axis 12. The valve seat 20 has a corresponding valve seat axis 22, which is also inclined at an angle ß with respect to the valve axis 12, wherein preferably β is equal to α. Thus, the valve member 9 and the valve seat 20 are tilted with respect to

Swivel plane of the valve element 9. In the present case, α and β are about 11 °. But it is also conceivable to choose for α and ß another Wnkelwert, in particular between 45 ° and 10 °. The described construction has the advantage that, when the bypass valve 8 is actuated, the valve element 9 is slid obliquely onto the valve seat 20 is, as indicated by an arrow, so that the force that is used to pivot the valve element 9, at the same time for pressing the

Valve element 9 is used against the valve seat 20. As a result, the tightness of the closed bypass valve 8 is ensured at all times. Due to the tilted arrangement of the valve element 9, only a partial force component resulting from the exhaust gas forces is transmitted to the lever 16 or the coupling rod 14, so that the forces to be transmitted are reduced overall. As a result, the electromechanical actuating motor 18 can also be dimensioned smaller, which results in further packaging advantages, in particular with regard to the available installation space.

Figures 4 and 5 show the transmission gear 17 each in one

simplified top view. The transmission gear 17 includes a

input-side gear 23, the rotation on the output shaft of the

electromechanical servo motor 8 - not shown here - is arranged. The gear 23 meshes with a first intermediate gear 24 which is rotatably mounted on an intermediate shaft 25. On the intermediate shaft 25, a second intermediate gear is further arranged, which is not visible in the illustrated plan view, since it is behind the intermediate gear 24. The second

Intermediate gear meshes with an output-side gear 26 which is rotatably mounted on an output shaft 27. On the shaft 27, the crank 16 is further rotatably arranged. The output shaft of the servo motor 8 in this case forms a first transmission axis 28, the intermediate shaft 25 a second

Transmission axis 29 and the output-side shaft, a third transmission axis 30th

Figure 5 shows a common arrangement of the transmission axes 28, 29 and 30 to each other, which in this case lie in a row or in a common plane.

FIG. 6 shows a particularly preferred arrangement of the transmission axes relative to each other, in which the transmission axis 29 is offset relative to the plane in which the transmission axes 28 and 30 lie. As a result, a triangular shape - as shown in Figure 6 by a drawn triangle - the

Transmission axes 28 to 30 realized to each other, whereby the width of the

Transmission gear 17 is reduced overall. The transmission gear 17 is thereby replaced by a banana shape, which leads to corresponding packaging Benefits leads. Appropriately, the transmission axes are arranged to each other such that they are adapted to the radius of the compressor and / or turbine volutes to a particularly favorable adaptation to the

To obtain exhaust gas turbocharger, or to adapt to its shape. Preferably, a corresponding transmission gear 17 is also used for the above-mentioned variable turbine geometry, regardless of the formation of the rest of the exhaust gas turbocharger, in particular independent of the presence or the formation of the bypass valve. 8

Claims

claims

1. exhaust gas turbocharger (1), in particular for a motor vehicle, with at least one turbine (2), which is associated with an actuatable bypass valve (8), and with an actuator (19) by a coupling rod (14) with a order a valve axis (12) displaceable valve element (9) of the bypass valve (8) is connected, characterized in that the coupling rod (14) at least substantially perpendicular and the valve axis (12) at least substantially parallel to the main axis (15) of the exhaust gas turbocharger (1) are aligned.

2. Exhaust gas turbocharger according to claim 1, characterized in that the actuator (19) comprises an electromechanical or electromagnetic actuator motor (18).

3. Exhaust gas turbocharger according to one of the preceding claims, characterized in that the in particular dish-shaped valve element (9) for opening or closing the bypass valve (8) about the valve axis (12) is formed foldable.

4. Exhaust gas turbocharger according to one of the preceding claims, characterized in that the in particular plate-shaped valve element (9) for opening or closing the bypass valve (8) about the valve axis (12) is formed laterally pivotable.

5. Exhaust gas turbocharger according to one of the preceding claims, characterized in that the laterally pivotable valve element (9) is tilted aligned with the pivoting plane.

6. Exhaust gas turbocharger according to one of the preceding claims, characterized in that the laterally pivotable valve element (9) is tilted about a valve axis perpendicular to the valve axis (12) lying longitudinal axis.

7. Exhaust gas turbocharger according to one of the preceding claims, characterized in that the bypass valve (8) is designed as a flat seat valve (10).

8. Exhaust gas turbocharger according to one of the preceding claims, characterized in that the actuator (19) comprises a transmission gear (17) which connects the servomotor (18) with the coupling rod (14).

9. Exhaust gas turbocharger according to one of the preceding claims, characterized in that the transmission gear (17) has three transmission axes (28, 29, 30) which are in a row or offset from each other.

10. Exhaust gas turbocharger according to one of the preceding claims, characterized in that the transmission axes (28, 29, 30) in one

Triangular shape to each other and / or on a radius with respect to the main axis (15) of the exhaust gas turbocharger (1).