GB2530824A

GB2530824A - Turbocharger wastegate linkage assembly

Info

Publication number: GB2530824A
Application number: GB1502440.9A
Authority: GB
Inventors: Brian David Eves
Original assignee: Ford Global Technologies LLC
Current assignee: Ford Global Technologies LLC
Priority date: 2015-02-13
Filing date: 2015-02-13
Publication date: 2016-04-06
Anticipated expiration: 2035-02-13
Also published as: GB2535273A; GB201520256D0; GB2530824B; DE102016102277A1; RU2016104244A; MX2016001337A; GB2535273B; RU2717198C2; RU2016104244A3; GB201502440D0

Abstract

A turbocharger wastegate linkage assembly 100 having a wastegate valve 126 with valve closure 127 configured to selectively control the flow of exhaust gases through a turbocharger turbine, an actuator 140 to open or close the valve, and a wastegate linkage 145 configured to transfer movement of the actuator 140 to the valve 126, wherein the turbocharger wastegate linkage assembly 100 has an abutment 150 positioned such that a portion of the linkage 148 or the valve closure 127 abuts the abutment 150 when the wastegate valve 126 is in an open position, thereby reducing slack in the turbocharger wastegate linkage 145. The abutment 150 may be located on the turbocharger housing (160, Fig. 5), and the linkage 145 preferably comprises a link member 146 having the actuator 140 at one end 147a, the closure 127 at the other end 147b, and an intermediate pivot point 147c. The assembly may be activated by a magnet, preferably an electromagnet.

Description

TURBOCHARGER WASTEGATE LINKAGE ASSEMBLY

The present disclosure relates a turbocharger wastegatc linkage assembly and particularly but not exclusively relates to a turbocharger wastegate linkage assembly comprising an end stop for the wastegate linkage.

Background

With reference to Figure, it is well known to provide an internal combustion engine 10 with a turbocharger 20 to improve its power output and reduce emissions. TypicaTly, the turbocharger 20 is arranged with an exhaust gas driven turbine 22 driving a compressor 24 mounted on the same shaft. In addition, such turbochargers 20 often incorporate a bypass valve, known as a wastegate valve 26, which is used to control the flow of exhaust gas in a bypass passage 28 arranged in parallel to the turbine 22 of the turbocharger. The wastegatc valve 26 may be used to modulate the amount of exhaust gas flowing through the turbine 22 and thereby change the power available to drive the compressor 24. Accordingly, the performance boost provided by the turbocharger 20 may be controlled by the position of the wastegate valve 26. Typically, an aim of the boosting by the turbocharger 20 is to run the engine 1 0 with the lowest possible level of throttling by throttle 12, thereby reducing the pumping losses.

With reference to Figure 2, the position of the wastegate valve 26 may be controlled by a control valve 30. The control valve 30 is in fluidic communication with first and second reference pressures via first and second inlets 32, 34 respectively. The control valve 30 modulates the first and second reference pressures by virtue of a movable element which is configured to selectively transmit the first or second reference pressures to an outlet 38 of the control valve. In this way, the control valve 30 provides an output pressure signal, which may be between the first and second reference pressures and which may be varied by changing a duty cycle of the movable element.

The movable element may be selectively moved by a solenoid, such that that the control valve 30 may comprise a pulse width modulated solenoid driven valve. An Engine Control Unit (ECU) 41 may send a signal to the control valve 30 to vary the bypass through the wastegate valve, e.g. depending on a pressure measured by a sensor 37 in the inlet manifold 36. In this way, the boost pressure provided by the turbocharger 20 can be controlled.

The output pressure signal from the control valve is in turn in fluidic communication with a wastegate capsule 40. The wastegate capsule 40 comprises a piston 42 acting against a spring 43. A connecting rod 44 attached to the piston 42 is configured to move the wastegatc valve 26 via a linkage 45. The linkage 45 may comprise a rotatable portion 46, which may rotate about an axis 46' to move the wastegate vaNe 26 away from or towards a corresponding valve seat. The modulated output pressure from the control valve 30 acts on the piston 42 against the spring 43 and thus opens or closes the wastegate valve 26.

Statements of Invention

According to a first aspect of the present disclosure there is provided a turbocharger wastegate linkage assembly comprising: a wastegate valve comprising a wastegate valve closure configured to selectively control the flow of exhaust gases through a turbocharger turbine; an actuator configured to open or close the wastegate valve; and a wastegatc linkage configured to transfer movement of the actuator to the wastegate valve, wherein the turbocharger wastegate linkage assembly further comprises an abutment, the abutment being positioned such that a portion of the wastegate linkage or the wastegate valve closure abuts the abutment when the wastegate valve is in an open position, thereby reducing slack in the turbocharger wastegate linkage.

The wastegate linkage may comprise a link member. The link member may be coupled to the actuator and the wastegate valve closure at first and second locations on the link member respectively. The link member may be pivotable about an axis that passes through a third location on the link member. The third location may be provided between the first and second locations on the link member. Alternatively, one of the first and second locations may be between the third location and the other of the first and second locations.

The portion of the wastegate linkage may abut the abutment when the wastegate valve is in the open position. Said portion of the wastegate linkage maybe positioned at or in the region of the second location on the link member.

The wastegate valve closure may abut the abutment when the wastegate valve is in the open position. The abutment may abut the valve closure on a surface of the valve closure that faces away from a valve seat of the wastegate valve.

The abutment may be provided within a flow path into or out of the turbocharger turbine. Alternatively, the abutment may be provided outside a flow path into or out of the turbocharger turbine.

The abutment may comprise an abutment surface. The abutment may comprise a resilient abutment surface.

The abutment and/or the portion of the wastegate linkage or the wastegate valve closure may comprise a magnet, such as a permanent magnet, configured to attract the abutment and the portion of the wastegate linkage or the wastegate valve closure together. The magnet may be an eleetro-magnet configured to be selectively activated. The electro-magnet may be configured to be activated when the wastegate valve is instructed to be in the open position.

According to a flirther aspect of the present disclosure there is provided a turbocharger housing for a turbocharger assembly, the turbocharger assembly comprising: a wastegate valve comprising a wastegate valve closure configured to selectively control the flow of exhaust gases through a turbocharger turbine; an actuator configured to open or close the wastegate valve; and a wastegate linkage coatigured to transfer movement of the actuator to the wastegate valve, wherein the turbocharger housing comprises an abutment, the abutment being positioned such that a portion of the wastegate linkage or the wastegate valve closure abuts the abutment when the wastegate valve is in an open position, thereby reducing slack in the turbocharger wastegate linkage.

According to a frirther aspect of the present disclosure there is provided a turbocharger wastegate valve assembly comprising: a wastegate valve configured to selectively engage a valve seat; and an end stop comprising an abutment surface, wherein the end stop is configured such that the wastegate valve abuts the abutment surface when the wastegate valve is in an open position.

A vehicle or engine may comprise the above-mentioned turbocharger wastegate linkage assembly, turbocharger wastegate valve assembly or turbocharger housing.

Brief Description of the Drawings

For a better understanding of the present disclosure, and to show more clearly how it maybe carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 shows a schematic view of a previously-proposed engine and turbocharger arrangement with a wastegate; Figure 2 shows a schematic view of a previously-proposed wastegatc assembly for controlling the position of a turbocharger wastegate; Figure 3 shows a schematic view of a wastegate linkage assembly according to a first

example of the present disclosure;

Figure 4 shows a schematic view of a wastegatc linkage assembly according to a second

example of the present disclosure;

Figure 5 shows a perspective view of a turbocharger housing according to a third

example of the present disclosure; and

Figure 6 shows a sectional view of a turbocharger housing according to a fourth

example of the present disclosure.

Detailed Description

With reference to Figures 3 to 6, the present disclosure relates to a turbocharger wastegate linkage assembly 100. The wastegate linkage assembly 100 comprises a wastegate valve 126 and an actuator 140 configured to open or close the wastegate valve. The wastegate linkage assembly 100 ftirther comprises a wastegate linkage 145 configured to transfer movement of the actuator 140 to the wastegate valve 126.

As described above with reference to Figures 1 and 2, the wastegate valve 126 may control the flow of exhaust gases through a turbocharger turbine and the operation of the wastegate valve 126 is similar to that described above. For example, a control valve may control the position of the wastegate valve 126 by virtue of a signal from an ECU 141. The signal from the ECU may at least in part depend on a pressure measured by a sensor 137 in the inlet manifold 136.

Again, as described above, the control valve 130 may modulate first and second reference pressures from respective first and second inlets 132, 134 to vary a pressure at an outlet 138. The pressure at outlet 138 is in turn in fluidic communication with the actuator 140. The actuator 140 comprises a piston 142 acting against a spring 143. A connecting rod 144 attached to the piston 142 is configured to move the wastegate valve 126 via the wastegate linkage 145. The modulated output pressure from the control valve 130 acts on the piston 142 against the spring 143 and thus opens or closes the wastegate valve 126. (Figures 3 and 4 depict the wastegate valve 126 in a partially open position.) Although the actuator 140 has been described as a pneumatic or hydraulic actuator, it is equally envisaged that the actuator may comprise a motor, such as a servo motor, or any other type of actuator that can convert the signal from ECU 141 into different wastegate valve positions.

Referring still to Figures 3 to 6, the wastegate linkage 145 may comprise a link member 146. The link member 146 maybe pivotably coupled to the actuator 140, e.g. an end of the connecting rod 144 may be coupled to the link member at a first location 147a on the link member. In addition, the link member 146 may be pivotably coupled to a movable wastegate valve closure 127 at a second location 147b on thc link member.

The wastegate valve closure 127 may selectively engage a corresponding waste gate valve seat 128 to selectively block flow through the wastegate valve 126.

The link member 146 may be pivotable about an axis 146' that passes through a third location l47c on the link member. The axis 146' and third location 147c may be fixed, c.g. relative to the turbocharger. As depicted, the third location 1 47c may be provided between the first and second locations 147a, 147b on the link member. Alternatively, one of the first and second locations may he between the third location and the other of the first and second locations. In either case, the link member 146 may transfer movement of the actuator 140 to the wastegate valve closure 127.

The turbocharger wastegate linkage assembly 100 further comprises an abutment 150 against which the wastegate linkage 145 andlor valve closure 127 may abut when the wastegate valve 126 is in an open position. The abutment 150 may be positioned such that the wastegate linkage 145 and/or valve closure 127 abut the abutment 150 when the actuator 140 is within its range of movement.

In a first example of the present disclosure depicted in Figure 3, the abutment 150 is positioned such that a portion 148 of the wastegate linkage 145 may abut the abutment when the wastegate valve 26 is in the open position. As depicted, in Figure 3 said portion 148 of the wastegate linkage may be positioned at or in the region of the second location 147b on the link member. However, in alternative examples, the abutment 150 may be positioned such that the contact portion 148 is provided between the first and third locations 147a, 147c (as depicted in Figure 5) or between the second and third locations 147b, I 47c (as depicted in Figure 6).

In a second example of the present disclosure depicted in Figure 4, the abutment 150 is positioned such that the wastegate valve closure 1 27 may abut the abutment 150 when the wastegatc valve 126 is in the open position. The abutment 150 may abut the valve closure 127 on a surface of the valve closure that faces away from the valve seat 128 of the wastegate valve.

In a further example of the present disclosure, both the abutments 150 from the first and second examples may be provided.

Referring now to Figures 5 and 6, as the wastegate valve 126 may be provided for the flow path bypassing the turbocharger turbine, the abutment 150 may be provided within the flow path into, around or out of the turbocharger turbine. Alternatively, the abutment may be provided outside of this flow path. In either case, a turbocharger housing, e.g. a turbine outlet housing, 160 may comprise the abutment 150. As depicted in Figure 5, the abutment 150 may be provided externally with respect to the flow path through the turbocharger housing 160, As depicted in Figure 6, the abutment 1 50 may be provided internally with respect to the flow path through the turbocharger housing 160. Accordingly, the abutment 1 50 may protrude from the turbine housing (inwardly or outwardly) in the region of the link member 146. In the case of the abutment 150 1 5 being provided inside the turbocharger housing, the abutment may be positioned behind the link member relative to the flow through the turbocharger or bypass. Accordingly, the abutment 150 may not interfere with the flow through the turbocharger or bypass.

In either case, the abutment 150 may be integral with, e.g. cast into, the turbocharger housing 160.

The wastegate linkage connections are generally simple pivots, which may have relatively large clearances to avoid friction, e.g. resulting from corrosion due to the harsh environment endured. As a result of these large clearances, when the previously-proposed wastegate valve is in the open position, the wastegate linkage can be heard to emit an undesirable rattle noise. However, with the examples of the present disclosure, when the wastegate valve 126 is in the open position, the contact with the abutment 150 reduces stack in the turbocharger wastegate linkage 145 and thereby reduces the rattle noise. The reduction in slack is due to the linkage being placed under compression or tension by virtue of a holding force transmitted from the actuator to the abutment 150.

The open position holding force from the actuator may for example be provided by the spring 143 in the actuator and/or the pressure acting on the piston 142. The actuator and/or abutment 150 may be configured, e.g. positioned, such that the open position holding force is sufficient to reduce the slack in the linkage to a level at which an audible rattle does not occur.

Additionally or alternatively, the open position holding force may be provided at least partially by a magnet (not shown). The abutment 150, the portion 148 of the wastegate linkage and/or the wastegate valve closure 127 may comprise the magnet. The magnet may attract the abutment ISO and the portion 148 of the wastegate linkage or the wastegate valve closure 127 together. The magnet may he a permanent magnet.

Alternatively, the magnet may be an clectro-inagnet configured to be selectively activated, e.g. by the ECU 141, only when the wastegate valve 126 is instructed to be in the open position. In this way the actuator 140 does not have to overcome all or any of the open position holding force when the wastegate valve is instructed to be open.

The abutment 1 50 may comprise an abutment surface, which the portion 148 of the wastegate linkage or the wastegate valve closure 127 may abut. The abutment surface may be resilient, e.g. such that it deforms wider action of the open position holding force. Such a resilient surface may reduce any shock loads applied as the wastegate valve opens and may further reduce the likelihood of any rattle in the wastegate linkage.

The calibration of the ECU 141 and/or the actuator spring 143 may ensure the open position is reached without excessively loading the wastegate linkage 145 or over-pressuring the actuator. In other words, the holding force may not unduly stress the linkage or actuator. Furthermore, an electrically driven actuator (or associated controller) may learn where the open end stop position is and learn to apply an appropriate load to the wastegate linkage 145 to prevent rattle occurring.

This disclosure describes the addition of an open limit end stop to the wastegate system at the wastegate valve. Currently, the maximum wastegate valve lift is only governed by the travel of the actuator or electric motor. Operating any of these parts at their limits does not load the wastegate linkage, hence rattle occurs. Loading of the wastegate linkage in the open valve condition is achieved by adding a positive stop, e.g. at or near a point where the wastegate linkage is coupled to the valve closure, thereby restricting wastegate opening before the actuator reaches maximum travel.

It will be appreciated by those skilled in the art that although the invention has been described by way of example, with reference to one or more examples, it is not limited to the disclosed examples and that alternative examples could he constructed without 6 departing from the scope of the invention as defined by the appended claims.

Claims

Claims 1. A turbocharger wastegate linkage assembly comprising: a wastegate valve comprising a wastegate valve closure configured to selectively control the flow of exhaust gases through a turbocharger turbine; an actuator configured to open or close the wastcgate valve; and a wastegate linkage configured to transfer movement of the actuator to the wastegate valve, wherein the turbocharger wastegate linkage assembly further comprises an abutment, the abutment being positioned such that a portion of the wastegate linkage or the wastegate valve closure abuts the abutment when the wastegatc valve is in an open position, thereby reducing slack in the turbocharger wastegate linkage.
2. The turbocharger wastegate linkage assembly of claim 1, wherein the wastegate linkage comprises a link member, the link member being coupled to the actuator arid the wastegate valve closure at first and second locations on the link member respectively.
3. The turbocharger wastegate linkage assembly of claim 2, wherein the link member is pivotable about an axis that passes through a third location on the link member.
4. The turbocharger wastcgate linkage assembly of claim 3, wherein the third location is provided between the first and second locations on the link member.
5. The turbocharger wastegate linkage assembly of any of claims 2 to 4, wherein the portion of the wastegate linkage abuts the abutment when the wastegate valve is in the open position and said portion of the wastegate linkage is positioned at or in the region of the second location on the link member.
6. The turbocharger wastegate linkage assembly of any of claims 2 to 4, wherein the wastegate valve closure abuts the abutment when the wastegate valve is in the open position and wherein the abutment abuts the valve closure on a surface of the valve closure that faces away from a valve seat of the wastegate valve.
7. The turbocharger wastcgate linkage assembly of any of the preceding claims, wherein the abutment is provided within a flow path into or out of the turbocharger turbine.
8. The turbocharger wastegate linkage assembly of any of claims 1 to 6, wherein the abutment is provided outside a flow path into or out of the turbocharger turbine.
9. The turbocharger wastegate linkage assembly of any of the preceding claims, wherein the abutment comprises a resilient surface.
10. The turbocharger wastegate linkage assembly of any of the preceding claims, wherein the abutment and/or the portion of the wastegate linkage or the wastegate valve closure comprises a magnet configured to attract the abutment and the portion of the wastegate linkage or the wastcgate valve closure together.
11. The turbocharger wastegate linkage assembly of claim 10, wherein the magnet is an electro-magnet configured to be selectively activated.
12. The turbocharger wastegate linkage assembly of claim 1 i, wherein the electro-magnet is configured to be activated when the wastegate valve is instructed to be in the open position.
13. A turbocharger housing for a turbocharger assembly, the turbocharger assembly comprising: a wastegate valve comprising a wastegate valve closure configured to selectively control the flow of exhaust gases through a turbocharger turbine; an actuator configured to open or close the wastegatc valve; and a wastcgate linkage configured to transfer movement of the actuator to the wastegate valve, wherein the turbocharger housing comprises an abutment, the abutment being positioned such that a portion of the wastcgate linkage or the wastegate valve closure abuts the abutment when the wastegate valve is in an open position, thereby reducing slack in the turbocharger wastegate linkage.
14. A vehicle or engine comprising the turbocharger wastegatc linkage assembly of any of claims 1 to 12 or the turbocharger housing of claim 13.
15. A turbocharger wastcgate linkage asscmbly or turbocharger housing substantially as described herein with reference to and as shown in Figures 3 to 6.Amendments to the claims have been filed as follows: Claims 1. A turbocharger wastegate linkage assembly comprising: a wastegate valve comprising a wastegate valve closure configured to selectively control the flow of exhaust gases through a turbocharger turbine; an actuator configured to open or close the wastegate valve; and a wastegate linkage configured to transfer movement of the actuator to the wastcgate valve, wherein the turbocharger wastegate linkage assembly further comprises an abutment, the abutment being positioned such that a portion of the wastegate linkage or the wastegate valve closure abuts the abutment when the wastegate valve is in an open position, thcreby reducing slack in the turbocharger wastegate linkage, and wherein the abutment is provided outside a flow path into, around or out of the 1.1') turbocharger turbine.2. The turbocharger wastegate linkage assembly of claim 1, wherein the wastegate linkage comprises a link membei, the link member being coupled to the actuator and the wastegate valve closure at first and second locations on the link member respectively. r3. [he turbocharger wastegate linkage assembly of claim 2, wherein the link member is pivotable about an axis that passes through a third location on the link member.4. The turbocharger wastegate linkage assembly of claim 3, wherein the third location is provided betwecn the first and second locations on the link member.5. The turbocharger wastegate linkage assembly of any of claims 2 to 4, wherein the portion of the wastegate linkage abuts the abutment when the wastegate valve is in the open position and said portion of the wastegate linkage is positioned at or in the region of the second location on the link member.6. The turbocharger wastegate linkage assembly of any of claims 2 to 4, wherein the wastcgate valve closurc abuts the abutment when the wastegate valve is in the open position and wherein the abutment abuts the valve closure on a surface of the valve closure that faces away from a valve seat of the wastegale valve.7. The turbocharger wastegate linkage assembly of any of the preceding claims, whcrcin the abutment comprises a resilient surface.8. The turbocharger wastegate linkage assembly of any of the preceding claims, wherein the abutment and/or the portion of the wastegate linkage or the wastegate valve closure comprises a magnet configured to attract the abutment and the portion of the wastegate linkage or the v'astegate valve closure togethei 9 The turbocharger wastegate linkage assembly of claim 8, wherein the magnet is LL) an electro-magnet configured to be selectively activated 1 10 The turbocharger wastegate linkage assembly of claim 9, wherem the electro-magnet is configured to be activated when the wastegate valve is instructed to be in the Nm open position. rII. A turbocharger housing for a turbocharger assembly, the turbocharger assembly comprising a wastegate valve comprising a wastegate valve closure configured to selectively control the flow of exhaust gases through a turbocharger turbine; an actuator configured to open or close the wastegate valve; and a wastegate linkage configured to transfer movement of the actuator to the wastegate valve, wherein the turbocharger housing comprises an abutment, the abutment being positioned such that a portion of the wastegate linkage or the wastegate valve closure abuts the abutment when the wastegate valve is in an open position, thereby reducing slack in the turbocharger wastegate linkage, and wherein the abutment is provided outside a flow path into, around or out of the turbocharger turbine.12. A vehicle or engine comprising the turbocharger wastegate linkage assembly of any of claims 1 to 10 or the turbocharger housing of claim 11.13. A turbocharger wastegate linkage assembly or turbocharger housing substantially as described herein with reference to and as shown in Figures 3 to 5. L0 r rN r