Control device of an exhaust gas guide section of an exhaust gas turbocharger

Abstract

The invention relates to a control device (8) of an exhaust gas guide section (1) of an exhaust gas turbocharger (2), wherein the control device (8) has a closure device (9) comprising a closure element (10) and an element lever (11), wherein the closure device (9) can be swivelled about an axis of rotation (19), and wherein the closure element (10) is designed for opening and closing a first flow cross-section (13) of the exhaust gas guide section (1), wherein the first flow cross-section (13) is formed in a separating wall lying between a first spiral channel (4) of the exhaust gas guide section (1) and a second spiral channel (5) of the exhaust gas guide section (1), and wherein the exhaust gas guide section (1) has a second flow cross-section (17) which is assigned a bypass channel (18) formed in the exhaust gas guide section (1), which is designed for bypassing an impingement of a turbine wheel formed in the exhaust gas guide section (1), and wherein the closure element (10) has a first element section (15) for closing the first flow cross-section (13) and a second element section (16), which can be used for closing the second flow cross-section (17), and wherein the element lever (11) has an arm section (21) designed for engaging into a hollow space (20) of the closure element (10), and wherein the hollow space (20) has an inner surface (23) and the arm section (21) has an outer surface (24) formed opposite the inner surface (23). According to the invention, an inner casing surface (44) of the inner surface (23) and a casing surface (31) of the outer surface (24) are identical in shape while having different dimensions, wherein the casing surface (31) has at least two different casing sections (32, 33).

Description

[0001] The invention relates to a control device of an exhaust gas routing section of an exhaust gas turbocharger of the type specified in the preamble of claim 1.

[0002] Exhaust gas routing sections for exhaust gas turbochargers, which include a control device for regulating the flow of a fluid, generally exhaust gas, through the exhaust gas routing section, are known. The control device is designed to open and close a bypass channel in the flowable exhaust gas routing section to bypass a turbine wheel rotatably arranged in a wheel chamber of the exhaust gas routing section. Furthermore, the control device can open or close a flow opening formed between two spiral channels of the exhaust gas routing section, allowing the exhaust gas to flow from one spiral channel to the other and vice versa.

[0003] With the aid of such a control device, it is possible at certain operating points of the exhaust gas turbocharger, particularly at points with high flow rates, to bypass the turbine wheel completely or partially, thus enabling efficient operation of the exhaust gas turbocharger. The efficient operation of the exhaust gas turbocharger depends on a specific opening characteristic of the control device, which must be designed to meet the requirements of the drive unit connected to the exhaust gas turbocharger, especially an internal combustion engine.

[0004] The control device comprises several interconnected components, allowing for relative movement of individual components. For example, a closing element of the control device, designed to close the bypass channel and / or the flow opening, has a degree of mobility relative to a lever arm of the control device, which is designed to move the closing element and receives it at one end. This mobility is necessary to prevent jamming in the exhaust gas routing section, for instance, if the lever arm pivots with the closing element. The relative mobility of the two components results in wear of the control device during operation of the exhaust gas turbocharger, which must be minimized.

[0005] German patent application DE 10 2017 202 132 A1 describes a control device for an exhaust gas turbocharger, which has a closing element mounted on a lever arm of the control device. The lever arm projects into a cavity of the closing element. To reduce wear, one end of the lever arm, which projects into the cavity, is designed to make contact with the closing element. For this purpose, the end of the lever arm has guide elements with guide surfaces that can come into contact with the closing element.

[0006] The patent application DE 10 2015 011 256 A1 also describes a control device for an exhaust gas turbocharger, which has a closing element and a lever arm projecting into the closing element, wherein the end of the lever arm has a conical and a cylindrical guide element, which are designed to bring about a sliding contact.

[0007] DE 20 2018 104 140 U1 and DE 20 2018 101 705 U1 disclose further control devices for exhaust gas turbochargers.

[0008] The object of the present invention is to provide an improved control device for an exhaust gas routing section of an exhaust gas turbocharger.

[0009] This problem is solved according to the invention with a control device for an exhaust gas routing section of an exhaust gas turbocharger having the features of claim 1. Advantageous embodiments with expedient and non-trivial further developments of the invention are specified in the dependent claims.

[0010] A control device according to the invention for an exhaust gas routing section of an exhaust gas turbocharger has a closing device comprising a closing element and an element lever, wherein the closing device is pivotable about a rotational axis. The closing element is designed to open and close a first flow cross-section of the exhaust gas routing section, wherein the first flow cross-section is formed in a partition located between a first spiral channel of the exhaust gas routing section and a second spiral channel of the exhaust gas routing section. The exhaust gas routing section has a second flow cross-section, which is associated with a bypass channel formed in the exhaust gas routing section, which is designed to bypass the flow approaching a turbine wheel formed in the exhaust gas routing section.The closing element comprises a first element section for closing the first flow cross-section and a second element section which can be used to close the second flow cross-section. The element lever is designed to engage in a cavity of the closing element. The cavity has an inner surface, and the arm section has an outer surface opposite the inner surface. According to the invention, an inner surface of the inner surface and a outer surface of the outer surface are identical in form but have different dimensions, with the outer surface comprising at least two different outer sections.

[0011] In principle, it is advantageous to implement a relative movement between the closing element and the element lever to prevent the closing element from tilting or jamming in the exhaust gas duct section. With the control device according to the invention, wear of the element lever and / or the closing element due to the relative movement is significantly reduced, since contact between the element lever, in particular the arm section, and the closing element can occur at various points on the arm section and the closing element. In other words, the contact between the arm section and the closing element, which is necessary for the reliable operation of the control device, is present in every position of the control device, but this contact can be as large as required.Furthermore, noise generation is also reduced due to the size-optimized contact design, which leads to size-optimized contact surfaces.

[0012] In one embodiment of the control device according to the invention, a movement gap is formed between the inner surface and the outer surface, the shape of which depends on the position of the control device. This means that the inner surface and the outer surface can be shaped depending on the operating points of a drive unit connected to the exhaust gas turbocharger.

[0013] In a further embodiment, the arm section is designed to support itself axially and / or radially against a cover element of the locking device, so that it is securely received in the cavity of the locking element.

[0014] The inner surface and the outer surface preferably have at least one frustoconical section.

[0015] In a further advantageous embodiment, the arm section extends along the longitudinal axis from its base surface, which is formed opposite a cavity base of the closing element, at least to a closing surface of the second element section, so that a preferred tightness can be achieved.

[0016] A particularly advantageous feature is a first transition section formed between the first and second shell sections, which connects the two shell sections to ensure a continuous surface along the longitudinal axis. This allows the arm section to slide freely on the locking element, and it is further advantageous for the first transition section to be curved.

[0017] Provided that the cavity floor has a groove at least at its bottom edge, which is adjacent to the first shell section, further improved sliding and thus a further reduction of wear is achievable.

[0018] Alternatively, the arm section can be secured by means of a pin which extends from the cavity floor along the longitudinal axis.

[0019] In summary, it can be said that the control device according to the invention is designed to reduce wear even at high temperatures, and that heat transfer from the closing element to the element lever is reduced, resulting in lower component temperatures. Furthermore, simple and cost-effective manufacturing, particularly using a casting process, is possible due to the simple contours of the closing element and the element lever, especially their contacting surfaces.

[0020] The pot-shaped design of the locking element and the arm section results in a weight-reduced control device.

[0021] Further advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. The features and combinations of features mentioned above in the description, as well as those mentioned below in the figure description and / or shown in the figures alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention. Identical or functionally equivalent elements are assigned identical reference numerals. The figures show: Fig. 1 in a perspective view a section along a cutting plane through an exhaust gas routing section of an exhaust gas turbocharger with a control device according to the state of the art, Fig. 2 in a perspective view a closing device of a control device according to the invention of an exhaust gas turbocharger in a first embodiment, Fig. 3 in one cut the locking device acc. Fig. 2 , Fig. 4 in a further cut the locking device acc. Fig. 2 , Fig. 5 in a top view the locking device acc. Fig. 2 , Fig. 6 in a section the closing device of the control device according to the invention in a second embodiment, Fig. 7 in a detailed view VII the locking device acc. Fig. 6 , Fig. 8 in an exploded view the control device according to the invention in the second embodiment, and Fig. 9 the control device according to the invention in a third embodiment.

[0022] According to Fig. 1 The exhaust gas flow section 1 of an exhaust gas turbocharger 2, as designed according to the invention, comprises an inlet channel 3 for the entry of a fluid flow into the exhaust gas flow section 1, generally exhaust gas from an internal combustion engine 7, a first spiral channel 4 and a second spiral channel 5 downstream of the inlet channel 3 for conditioning the flow, and an outlet channel (not shown) downstream of the spiral channels 4, 5, through which the exhaust gas can escape from the exhaust gas flow section 1 in a controlled manner. A wheel chamber (not shown) is formed between the spiral channels 4, 5 and the outlet channel, in which a turbine wheel (not shown) is rotatably mounted.

[0023] In the present embodiment, the exhaust gas routing section 1 is connected to an exhaust manifold 6 of the internal combustion engine 7, so that the exhaust gas of the internal combustion engine 7 can enter the spiral channels 4, 5 via the inlet channel 3 to act on the turbine wheel.

[0024] To adapt the operating behavior of the exhaust gas turbocharger 2 to the fluid flow of the internal combustion engine 7, and thus to the internal combustion engine 7, a control device 8 for separating and connecting the first spiral channel 4 and the second spiral channel 5 is arranged in the exhaust gas routing section 1. The control device 8 has a closing device 9 comprising a closing element 10 and an element lever 11, wherein the element lever 11 is designed to pivot the closing element 10 by a pivoting angle.

[0025] For the separation and connection of the two spiral channels 4, 5, the closing element 10 is arranged in a flow opening 12, which is designed to allow flow through the two spiral channels 4, 5.

[0026] In a first position, the closed position of the locking element 10, as described in Fig. 1 As shown, the two spiral channels 4, 5 are completely separate and can flow through each other, with the flow opening 12 being completely closed by means of the closing element 10. The exhaust gas from the internal combustion engine 7 flows through the two spiral channels 4, 5, with a first part of the exhaust gas flowing through the first spiral channel 4 and a second part of the exhaust gas flowing through the second spiral channel 5.

[0027] In a second position of the closing element 10, which is not shown in detail, the flow opening 12 is fully open and exhaust gas can flow from the first spiral channel 4 into the second spiral channel 5 and vice versa. This means that exhaust gas can flow from one spiral channel 4; 5 into the other spiral channel 5; 4 via the flow opening 12, which has a first flow cross-section 13.

[0028] The closing element 10 is to be positioned in further intermediate positions between the first position and the second position, so that the first flow cross-section 13 can be adapted to a corresponding requirement in order to achieve the best possible efficiency of the exhaust gas turbocharger 2 according to the amount of exhaust gas flowing through it.

[0029] To bring about a preferential opening of the first flow cross-section 13, the closing element 10 is designed to have a pot-shaped outer contour 14.

[0030] The closing element 10 has a first element section 15 for closing the first flow cross-section 13 and a second element section 16, which can be used to close a second flow cross-section 17 formed in the exhaust gas routing section 1.

[0031] The second flow cross-section 17 is designed to bypass the turbine wheel. In other words, the exhaust gas flowing through the second flow cross-section 17 is routed past the turbine wheel, and the turbine wheel is not subjected to this exhaust gas flowing through the second flow cross-section 17. The second flow cross-section 17 is formed in a bypass channel 18, which is also commonly referred to as a wastegate channel. The closing device 9 is designed to pivot about a rotary axis 19.

[0032] The in the Figuren 2 bis 7 The illustrated locking element 10 of the control device 8 according to a first and a second embodiment also has an approximately pot-shaped outer contour 14, wherein an arm section 21 of the element lever 11, which is designed to face the locking element 10, is arranged to engage in a cavity 20 of the locking element 10.

[0033] The closing device 9 designed according to the first embodiment also has the arm section 21 in a cup-shaped or pot-like form. The arm section 21 can be inserted into the closing element 10 by forming a movement gap 22, wherein the movement gap 22 is formed between an inner surface 23 of the cavity 20 and an outer surface 24 of the arm section 21.

[0034] The inner surface 23 and the outer surface 24 are in partial contact with each other, depending on the position of the locking device 9. In other words, in one position of the locking device 9, a portion of the outer surface 24 contacts a portion of the inner surface 23, thus the movement gap 22 between these portions is almost zero, and between the remaining portions of the inner surface 23 and the outer surface 24 it is correspondingly large. Which portions of the inner surface 23 contact which portions of the outer surface 24, and their size, as well as the movement gap 22, varies from position to position of the locking device 9. Therefore, the movement gap 22 between the inner surface 23 and the outer surface 24 is determined by the position of the control device 8.

[0035] This further means that the inner surface 23 is approximately, but not completely, complementary to the outer surface 24. In other words, the inner surface 23 and the outer surface 24 are identical in form, but have different dimensions.

[0036] The closing element 10 has its second element section 16, which, in order to bring about a closure of the second flow cross-section 17, has a closing surface 25 which is formed facing away from a cover surface 26 of the second element section 16.

[0037] The arm section 21, which is cup-shaped, extends from a cavity base 28 of the locking element 10 along a longitudinal axis 27 of the locking element 10 at least as far as the locking surface 25. Advantageously, it extends over the locking surface 25.

[0038] To axially secure the arm section 21 in the cavity 20, a cover element 29, in this embodiment annular in shape, is formed which is attached to the inner surface 23 of the closing element 10, is supported on it, and at least partially encompasses, or in other words covers, a section surface 30 of the arm section 21 in a radial direction.

[0039] In this first embodiment, a lateral surface 31 of the outer surface 24 has two differently shaped lateral sections, a first lateral section 32 and a second lateral section 33. The two lateral sections 32, 33 are shaped like truncated cones, the top surfaces of which, i.e., the surfaces with the smaller diameter, face the cavity floor 28. This results in a widening of the lateral surface 31 extending from the cavity floor 28. A bottom surface 34 of the outer surface 24, which is located opposite the cavity floor 28, is flat according to the first embodiment. Thus, an inner lateral surface 44 of the inner surface 23 and the lateral surface 31 of the outer surface 24 are identical in shape, but with different dimensions, and the lateral surface 31 has at least two different sections, the first lateral section 32 and the second lateral section 33.

[0040] In Fig. 5 The locking device 9 according to the first embodiment is shown in a top view. When the element lever 11 is rotated in the direction of the arrow, the movement gap 22 between the cavity floor 28 and the floor surface 34 is increased until the section surface 30 abuts the cover element 29, causing the arm section 21 to be supported axially and radially against the cover element 29. Due to an asymmetric force acting on the arm section 21, this causes a tilting movement in the cavity 20 in the direction of the Fig. 3 executes the indicated movement arrow.

[0041] The tilting movement, which can also be described as a coordinated tilting movement, is limited by the corresponding design of at least the inner surface 23 and the outer surface 24, and preferably the bottom surface 34 and / or the cavity floor 28. In other words, a relative movement can be realized between the arm section 21 and the closing element 10, which is low-wear and low-noise.

[0042] The maximum tilt of the locking element 10 relative to the arm section 21 should preferably not exceed 1.35°. To ensure that this maximum tilt is maintained, in addition to the axial securing of the arm section 21 by means of the cover element 29, a first angle α is formed between the shell sections 32, 33, which, with respect to a virtual plane E which is parallel to the base surface 34, preferably has a value in the range between 91° and 120° and preferably 95°.

[0043] Starting from the virtual plane E, the arm section 21 extends along the longitudinal axis 27 for at least a first length L1, which corresponds to an axial distance between the closing surface 25 and the virtual plane E. Starting from the bottom surface 34, the arm section 21 extends along the longitudinal axis 27 to the closing surface 25 for a second length L2, such that the axial extent of the first shell section 32 corresponds to a difference between the second length L2 and the first length L1.

[0044] Starting from the closing surface 25, the cover element 29 with its underside 41, which is formed opposite the section surface 30, is arranged at an axial distance with a third length L3, wherein a further movement gap 42 is formed between the cover element 29 and the arm section 21, in particular its section surface 30, especially if the bottom surface 34 contacts the cavity floor 28, wherein, however, a fourth length L4, over which the arm section 21 extends from the virtual plane E along the longitudinal axis 27, is greater than the first length L1 and less than the sum of the first length L1 and the third length L3.

[0045] Preferably, the second length L2 is larger than the first length L1, which in a preferred embodiment is 80% of the second length L2.

[0046] The first lateral section 32 is inclined relative to the base surface 34 at a second angle β, which generally has a value greater than the value of the first angle a, and preferably lies in a range of values ​​between 120° and 150°, more preferably having a value of 135°.

[0047] A first transition section 35 is formed between the first shell section 32 and the second shell section 33, connecting the two shell sections 32, 33 in such a way that a continuous surface 31 along the longitudinal axis 27 is achieved. The first transition section 35 is curved.

[0048] Likewise, a second transition section 38 is formed between a first inner surface section 36 of the inner surface 44, which is formed opposite the first shell section 32, and a second inner surface section 37 of the inner surface 44, which is formed opposite the second shell section 33, and which is adapted to the first transition section 35 according to the shape identity and the different dimensions of the inner surface 23 and the outer surface 24.

[0049] To enable further free movement of the closing element 10, the cavity floor 28 has at least at its bottom edge 39, which is adjacent to the first shell section 32, a groove 40, which in the present embodiment is formed in the form of an annular groove.

[0050] In the Figuren 6 bis 8 The control device 8 according to the invention is shown in the second embodiment. The arm section 21 is secured by means of a pin 43, which extends from the cavity base 28 of the locking element 10 along the longitudinal axis 27. Fig. 7 In a detailed view VII, the closing device 9 of the control device 8 according to the invention is shown in the area of ​​the transition sections 35, 38. Naturally, the virtual plane E is arranged in the axial direction along the longitudinal axis 27, intersecting the first transition section 35.

[0051] It should be noted that the term "surface 31" refers at least to the surface of the arm section 21, which extends axially along the longitudinal axis 27 from the base surface 34 over the second length L2. This also applies to the inner surface 44. In other words, the surfaces 31 and 44 can contact each other at some point, at least axially, over the second length L2.

[0052] In a third embodiment of the control device 8 according to the invention, the closing surface 25 is inclined with respect to the longitudinal axis 27, as shown in Fig. 9 is illustrated. To achieve a lightweight construction, the second element section 16 could also be hollow or at least partially hollow.

[0053] The control device 8 according to the invention now comprises a rotationally symmetrical surface formed between the closing element 10 and the arm section 21, which provides axial force application, concentric positioning, and a radial stop for the closing element 10. The tendency of the closing element 10 and the arm section 21 to wear, which occurs as a result of pressure pulsations during operation of the exhaust gas turbocharger 2, can be eliminated by a, in simplified terms, conical guide. An axial contact surface formed between the cavity floor 28 and the base surface 34 is further provided to ensure damage-free force application. An outer radial portion of the total contact surface between the closing element 10 and the arm section 21 is crucial for reducing the movement caused by pressure pulsations during operation.Thus, in the overall kinematics of the control device 8 according to the invention, the force pulsation is minimized. Reference symbol list

[0054] 1 Exhaust gas routing section 2 Exhaust gas turbocharger 3 Inlet channel 4 First spiral channel 5 Second spiral channel 6 Exhaust manifold 7 Internal combustion engine 8 Control device 9 Closing device 10 Closing element 11 Element lever 12 Flow opening 13 First flow cross-section 14 Outer contour 15 First element section 16 Second element section 17 Second flow cross-section 18 Bypass channel 19 Axis of rotation 20 Cavity 21 Arm section 22 Movement gap 23 Inner surface 24 Outer surface 25 Closing surface 26 Cover surface 27 Longitudinal axis 28 Cavity bottom 29 Cover element 30 Section surface 31 Shell surface 32 First shell section 33 Second shell section 34 Bottom surface 35 First transition section 36 First inner surface section 37 Second inner surface section 38 Second transition section 39 Bottom edge 40 Groove 41 Underside 42 Further movement gap 43 Pin 44 Inner surface Virtual plane L1 First length L2 Second length L3 Third length L4 Fourth length α First angle β Second angle

Claims

1. Control device (8) of an exhaust gas guide section (1) of an exhaust gas turbocharger (2), wherein the control device (8) has a closing device (9) comprising a closing element (10) and an element lever (11), wherein the closing device (9) is pivotable about a pivot axis (19), and wherein the closing element (10) is formed for opening and closing a first flow cross-section (13) of the exhaust gas guide section (1), wherein the first flow cross-section (13) is formed in a partition wall located between a first spiral channel (4) of the exhaust gas guide section (1) and a second spiral channel (5) of the exhaust gas guide section (1), and wherein the exhaust gas guide section (1) has a second flow cross-section (17) which is associated with a bypass channel (18) formed in the exhaust gas guide section (1), said bypass channel being designed to bypass an inflow to a turbine wheel formed in the exhaust gas guide section (1), and wherein the closing element (10) has a first element section (15) for closing the first flow cross-section (13) and a second element section (16) which can be used to close the second flow cross-section (17), and wherein the element lever (11) has an arm section (21) designed to engage in a cavity (20) of the closing element (10), and wherein the cavity (20) has an inner surface (23) and the arm section (21) has an outer surface (24) formed opposite the inner surface (23), characterized in that an inner shell surface (44) of the inner surface (23) and a shell surface (31) of the outer surface (24) are designed to be identical in shape but with different dimensions, wherein the shell surface (31) has at least two different shell sections (32, 33), and wherein a cavity bottom (28) of the locking element (10) has a groove (40) at least at its base edge (39), which is formed adjacent to the first shell section (32).

2. Control device (8) according to claim 1, characterized in that a movement gap (22) is formed between the inner surface (23) and the outer surface (24), which is formed depending on a position of the control device (8).

3. Control device (8) according to claim 1 or 2, characterized in that the arm section (21) is formed to be supported axially and / or radially on a cover element (29) of the closing device (9).

4. Control device (8) according to any one of the preceding claims, characterized in that the inner shell surface (44) and the shell surface (31) have at least one truncated cone-shaped section.

5. Control device (8) according to any one of the preceding claims, characterized in that the arm section (21) extends along the longitudinal axis (27) starting from its base surface (34), which is formed opposite a cavity bottom (28) of the closing element (10), extending at least up to a closing surface (25) of the second element section (16).

6. Control device (8) according to any one of the preceding claims, characterized in that a first transition section (35) is formed between the first shell section (32) and the second shell section (33), which is formed to connect the two shell sections (32, 33) to each other in order to produce a continuous course of the shell surface (31) along the longitudinal axis (27).

7. Control device (8) according to claim 6, characterized in that the first transition section (35) is curved.

8. Control device (8) according to any one of the preceding claims, characterized in that the arm section (21) is pot-shaped.

9. Control device (8) according to any one of the preceding claims, characterized in that the arm section (21) is secured by means of a pin (43) which is formed extending from the cavity bottom (28) along the longitudinal axis (27).

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