PRESSURE-ACTIVATED WASTEGATE

Abstract

System (200) for one motor (12), comprising: - an engine inlet (23) with an air inlet throttle (22) which is flow-coupled with an engine inlet manifold (24) along an inlet channel (18), and a compressor (90) for charging an inlet air charge received along the inlet channel (18); - a first ejector (206) positioned above the air inlet throttle (22) and controlled by a first valve (208); - a second ejector (80) positioned in a compressor bypass stream and controlled by a second valve (86); - a common actuator (44) configured to simultaneously adjust a position of the first valve (208) and the second valve (86); and - a channel (84) connecting the second ejector (80) to the actuator (44), which is designed to direct the negative pressure generated by the second ejector (80) to the actuator (44); - a ventilation duct (202) that connects the duct (84) upstream of the compressor (90) to the inlet duct (18); and - a ventilation valve (204) positioned in the ventilation duct (202) or at an intersection of the ventilation duct (202) with the channel (84).

Description

[0001] The present disclosure relates to an internal combustion engine.

[0002] US 2011 / 0088390A1 discloses a method for zone control of a wastegate in a turbocharged internal combustion engine. JP 2003-201927A discloses a vacuum supply device.

[0003] Turbochargers can improve engine torque / power density. A turbocharger typically contains a compressor and a turbine connected by a drive shaft, with the turbine coupled to the exhaust manifold and the compressor to the intake manifold. In this way, the exhaust-driven turbine supplies energy to the compressor to increase the pressure in the intake manifold (for example, boost pressure) and increase the airflow into the engine. The boost pressure can be controlled by adjusting the amount of gas reaching the turbine, for example, using a wastegate.

[0004] Wastegates can be pneumatically, hydraulically, or electrically actuated. In one example, a wastegate can be actuated by boost pressure generated by the turbocharger. However, it can be advantageous to open the wastegate under low-boost or no-boost conditions to reduce pumping losses and improve fuel economy. Thus, vacuum-actuated wastegates have been developed to allow wastegate control under low-boost conditions. Although vacuum-actuated wastegates can provide robust wastegate control under high engine vacuum conditions, the intake manifold vacuum used to provide the necessary vacuum for wastegate actuation is not available during higher boost conditions. A separate vacuum pump may be provided to supply the required vacuum when engine vacuum is unavailable, resulting in fuel waste.

[0005] The inventors have recognized the problems with the above approach and offer a system with the features of claim 1, a method with the features of claim 6, and a method with the features of claim 15 to address these problems, at least partially. Preferred embodiments are specified in the further claims. In one embodiment, a method comprises, when the charge is below a threshold, generating a vacuum with an actuator in a first position by directing air from a compressor outlet to an inlet manifold through a first ejector, and, when the charge is above the threshold, generating a vacuum with the actuator in a second position by directing air from the compressor outlet to a compressor inlet through a second ejector.

[0006] In this way, two ejectors can be provided: one for generating a vacuum under higher boost conditions via the second ejector positioned in the compressor flow path, and the other for generating a vacuum under low or no boost conditions via the first ejector positioned above the engine throttle. The flow through the ejectors can be controlled, in one example, by separate drive flow control valves actuated by a common actuator. This allows vacuum to be generated under a wide variety of operating conditions.

[0007] The above advantages and further advantages and features of the present description will be readily apparent from the following detailed description, either considered alone or in conjunction with the accompanying drawings.

[0008] It is understood that the above summary is intended to present, in simplified form, a selection of concepts that are described in more detail in the full description. It is not intended to reveal any key or essential features of the claimed invention, the scope of which is defined solely by the claims following the full description. Furthermore, the claimed invention is not limited to implementations that address any disadvantages mentioned above or in any other part of this disclosure. Fig. Figure 1 shows a schematic diagram of an engine containing an ejector that supplies negative pressure to a wastegate actuator, according to an embodiment of the present disclosure. Fig. 2 shows the engine of Fig. 1 with additional wastegate actuation mechanisms. Fig. Figure 3 shows a schematic diagram of an engine containing an ejector that supplies vacuum to a wastegate actuator, according to another embodiment of the present disclosure. Fig. 4 shows the engine of Fig. 3 with additional wastegate actuation mechanisms. Fig. Figure 5 is a flowchart illustrating a method for generating negative pressure according to an embodiment of the present disclosure. Fig. 6 and Fig. Figure 7 are schematic diagrams of double ejector drive current control provided by a single actuator according to embodiments of the present disclosure. Fig. Figure 8 is a flowchart illustrating a method for controlling motive current through multiple ejectors with an actuator according to an embodiment of the present disclosure. Fig. 9 and Fig. Figure 10 shows various motor operating parameters with coordinated control of the double ejector drive control with the single actuator.

[0009] Wastegates can provide boost control by diverting exhaust gas around a turbine. To provide wastegate actuation under a wide variety of engine conditions, boost pressure, acting as the wastegate control signal, can also be used to generate the vacuum required to actuate the wastegate. An ejector positioned in either the compressor or turbine bypass stream can generate the vacuum that is directed to the wastegate actuator. Alternatively, the ejector can be placed between other suitable pressure differentials in the exhaust port, air duct, or a combination of both. When excess boost is available to generate the vacuum via the ejector, the wastegate opens. To provide a variable boost limit, a vent valve can be included to divert some or all of the vacuum away from the actuator.To actuate the wastegate under low or no boost conditions, an intake manifold vacuum can also be supplied to the wastegate. This vacuum can be supplied directly from the intake manifold or generated by an ejector coupled via the throttle. In this way, the wastegate can be vacuum-actuated under both high and low boost conditions.

[0010] Fig. 1 and Fig. Figure 2 shows engine diagrams illustrating wastegate actuation with vacuum generated by a charge ejector coupled via a compressor. Fig. 3 and Fig. Figure 4 shows engine diagrams illustrating wastegate actuation with vacuum generated by a turbocharged ejector coupled via a turbine. Fig. 5 is a flowchart that shows a process for generating a vacuum using the method described in Fig. 2 or Fig. 4 represents the system shown.

[0011] To provide efficient control of vacuum generation, the drive flow of the charging ejector (for example, in the case of an ejector coupled via the compressor or turbine) can be controlled by a drive flow control valve in conjunction with a drive flow control valve that controls the drive flow of the throttle ejector. Both drive flow control valves can be actuated by a single actuator. Furthermore, under certain conditions, the drive flow control valve controlling the ejector coupled via the compressor can act as a pump reserve valve, thereby reducing the size of the compressor bypass valve and facilitating a reduction in the number of compressor pumps.

[0012] Fig. 6 and Fig. Figure 7 shows motor diagrams illustrating the control of two ejectors by a single actuator. Fig. 8 is a flowchart that shows a process for generating a vacuum using the method described in the Fig. 6 and Fig. The system shown in section 7 represents the system shown. Fig. 9 and Fig. Figure 10 represents different engine operating parameters when generating vacuum with the two ejectors controlled by a single actuator.

[0013] Fig. Figure 1 shows an exemplary engine system 10, which includes an engine 12. In this example, the engine 12 is a spark-ignition engine of a vehicle, wherein the engine contains several cylinders 14, each cylinder containing a piston. Combustion events in each cylinder 14 drive the pistons, which in turn rotate a crankshaft 16, as is well known to those skilled in the art. Furthermore, the engine 12 can contain several engine valves, wherein the valves are coupled to the cylinders 14 and control the intake and exhaust of gases in the several cylinders 14.

[0014] Engine 12 includes an engine inlet 23 and an engine outlet 25. The engine inlet 23 contains an air inlet throttle 22, which is flow-coupled to an engine inlet manifold 24 along an inlet channel 18. Air can enter the inlet channel 18 from an air intake system (AIS), which includes an air filter 33 connected to the vehicle's environment. The position of the throttle 22 can be changed by a control 50 via a signal supplied to an electric motor or actuator included with the throttle 22 – a configuration commonly referred to as electronic throttle control (ETC). In this way, the throttle 22 can be actuated to modify the intake air supplied to the inlet manifold and the multiple cylinders 14.The inlet 23 can contain an air mass sensor 58 (in the inlet channel 18) and an inlet manifold pressure sensor 60 (in the inlet manifold 24) for supplying respective signals MAF and MAP to the control 50.

[0015] The engine outlet 25 contains an exhaust manifold 48, which leads to an exhaust port 35 that discharges exhaust gas into the atmosphere. The engine outlet 25 can contain one or more exhaust aftertreatment devices 70, which are located close to the engine. The one or more exhaust aftertreatment devices can include a three-way catalytic converter, a NOx storage catalyst, a diesel particulate filter, an oxidation catalyst, etc. It is understood that other components may be included in the engine, such as various valves and sensors, as will be explained further below.

[0016] In some embodiments, the engine system 10 is a turbocharged engine system, which further includes a turbocharging device. In the present example, the intake duct 18 contains a compressor 90 for supercharging an intake air charge received along the intake duct 18. A charge air cooler 26 (or intercooler) is coupled downstream of the compressor 90 to cool the supercharged air charge before it is supplied to the intake manifold. In embodiments where the turbocharging device is a turbocharger, the compressor 90 can be coupled to and driven by a turbine 92 in the engine outlet 25 of the engine system 10. Furthermore, the compressor 90 can be driven, at least partially, by an electric motor or a crankshaft 16.

[0017] An optional bypass channel 28 can be coupled via the compressor 90 to redirect at least a portion of the inlet air compressed by the compressor 90 back upstream of the compressor. The volume of air redirected through the bypass channel 28 can be controlled by opening the compressor bypass valve (CBV) 30, which is located in the bypass channel 28. By controlling the CBV 30 and changing the volume of air redirected through the bypass channel 28, a boost pressure provided downstream of the compressor can be regulated. This enables boost control and pump control.

[0018] Likewise, an optional bypass channel 40 can be coupled via the turbine 92 to route at least a portion of the exhaust gas around the turbine 92, thereby controlling the turbine speed and thus the boost pressure provided by the engine. The amount of exhaust gas routed around the turbine 92 can be controlled by opening a wastegate 20 positioned in the bypass channel 40. The wastegate 42 can be moved by a wastegate actuator 44, which can be a solenoid actuator, a hydraulic actuator, or, in the example shown, a vacuum-operated actuator.

[0019] To generate negative pressure for driving the wastegate actuator 44, the second ejector 80 can be positioned in the compressor bypass flow. As shown, the second ejector 80 is positioned in a separate bypass channel 82 around the compressor 90, parallel to the bypass channel 28. In some embodiments, however, the second ejector 80 can be positioned within the bypass channel 28. High-pressure inlet air from the compressor outlet can flow through the second ejector 80 (airflow through the channels and lines of Fig. (1 are generally indicated by arrows) and flow back to the low-pressure area of ​​the compressor inlet. The negative pressure generated by the second ejector 80 can be directed via channel 84 to the wastegate actuator 44.

[0020] The second ejector 80 can be an ejector, an injector, a suction device, an extractor, a Venturi, a jet pump, or a similar passive device. The second ejector 80 can have an upstream drive inlet through which air enters the second ejector, a throat or a carry-in inlet that is flow-coupled to the wastegate actuator 44 via channel 84, and a mixed-flow outlet through which air that has flowed through the second ejector 80 can exit and be directed to a low-pressure sink, such as the inlet channel 18 upstream of the compressor 90 (it can, for example, be directed to the inlet of the compressor 90). Air flowing through the drive inlet can create a low pressure in the second ejector 80, thereby generating a low pressure transmitted to the throat (or the carry-in inlet) and drawing a vacuum at the throat.The vacuum at the throat of the second ejector 80 draws air from channel 84, thereby supplying vacuum to the wastegate actuator 44. To control the airflow through the second ejector 80, an optional drive flow control valve 86 can be positioned upstream, downstream, or midstream of the ejector drive flow in bypass channel 82. Furthermore, an optional check valve can allow the wastegate actuator 44 to retain any portion of its vacuum should the pressures in the drive inlet of the second ejector 80 and the vacuum actuator equalize. Such a check valve can employ additional vent valves to prevent the wastegate from remaining permanently open. In this example, the second ejector 80 is a three-channel device comprising a drive inlet, a mixed-flow outlet, and a throat / carry-on inlet.However, in other embodiments of the second ejector 80, a check valve may be integrated into the second ejector 80.

[0021] The engine system 10 may also include a control system 46, which comprises a control unit 50, sensors 51, and actuators 52. Example sensors include the engine speed sensor 54, the engine coolant temperature sensor 56, the mass airflow sensor 58, the manifold air pressure sensor 60, the compressor inlet pressure sensor 32, and the throttle inlet pressure sensor 34. Example actuators include the CBV 30, the ejector drive control valve 86, the throttle 22, and engine valves, fuel injectors, and other components located in the Fig. 1 are not shown. The controller 50 may also contain physical memory with instructions, programs and / or code for operating the motor. Exemplary routines executed by the controller 50 are shown in the Fig. 5 and Fig. 8 shown.

[0022] Thus, the system of Fig. 1. A vacuum-operated wastegate valve is provided to control boost pressure by adjusting the amount of exhaust gas bypassing a turbocharger turbine. The wastegate actuator can receive a vacuum generated by passing air through a secondary ejector coupled via a compressor of the turbine. In this way, the wastegate valve can be opened based on the provided boost pressure (for example, the amount of air passed around the compressor and through the secondary ejector), as the vacuum supplied to the wastegate actuator increases with increasing throttle inlet pressure (for example, boost pressure). However, additional control of the wastegate actuator may be desirable. For example, it may be desirable to open the wastegate valve under low or no boost conditions to improve fuel economy.Furthermore, it may be desirable to actively control the boost pressure level with the wastegate actuator by selectively supplying negative pressure to the wastegate actuator. Fig. Figure 2 shows an engine system 200, which has the features of Fig. 1 plus additional, optional components to provide charging control and wastegate actuation under low charging conditions.

[0023] Motor system 200 contains similar features to motor system 10, including motor 12, compressor 90, turbine 92, second ejector 80, which supplies vacuum to wastegate actuator 44, and other previously described components. Channel 84, which supplies vacuum from the second ejector to wastegate actuator 44, is described in Fig. Figure 2 shows the entire length from the second ejector 80 to the actuator 44. To provide active boost control via actuation of the wastegate 42, a vent line 202 can be provided to couple the channel 84 upstream of the compressor 90 to the inlet channel 18. A vent valve 204 can be positioned in the vent line 202 or at the intersection of the vent line 202 with the channel 84. The vent valve 204 can be controlled by the controller 50 to adjust the vacuum level supplied to the wastegate actuator 44, with excess vacuum being returned to the inlet via the vent line 202. Thus, active boost pressure control can be provided by controlling the vent valve 204.

[0024] To open the wastegate 42 under low or no boost conditions (for example, when insufficient vacuum is generated via the second ejector 80), vacuum can be directed from the intake port or intake manifold 24 to the wastegate actuator 44. To provide intake manifold vacuum, a first ejector 206 can be coupled via the throttle 22. The first ejector 206 can generate vacuum from the intake air flow from upstream of the throttle to downstream of the throttle. The vacuum generated by the first ejector 206 can be directed to port 84 and / or through the vent valve 204. Flow control through the first ejector 206 can be provided by the ejector flow control valve 208, which can be positioned either upstream or downstream of the first ejector 206.

[0025] The wastegate actuator can be controlled either by the drive flow valve (for example 86, 208) or by the vent valve 204, which either applies or releases a vacuum.

[0026] A vacuum reservoir 210 can be flow-coupled with both the second ejector 80 and the first ejector 206 as well as the wastegate actuator 44. As in Fig. As shown in Figure 2, a channel from reservoir 210 and a channel from the first ejector 206 intersect with channel 84 and are thus flow-coupled. This allows vacuum to be directed from both reservoir 210 and the first ejector 206 to the wastegate actuator 44. In this way, vacuum can be stored in reservoir 210 and applied to the wastegate actuator 44 if the pressure drop at the second ejector 80 and / or first ejector 206 is insufficient to control the position of the wastegate 42. Furthermore, a first check valve 212 and a second check valve 214 can prevent vacuum release from reservoir 210 and / or ensure that vacuum flows only from the second ejector 80 or first ejector 206 to the wastegate actuator 44 and not in the other direction. Similar to the Fig. 1. Airflow to the various channels and passages of the motor system 200 is directed by the arrows from Fig. 2 shown.

[0027] The in Fig. The configuration shown is not limiting, as other configurations are possible. For example, the storage tank 210 can be omitted. Likewise, the first ejector 206 can be omitted, and vacuum from the intake manifold 24 can be supplied to channel 84 and the wastegate actuator 44 via a direct supply line that is coupled to the intake channel 18 downstream of the throttle 22. Although the Fig. 1 and Fig. While diagrams 2 show the vacuum generated by the second ejector in the compressor flow path and / or the vacuum from the intake manifold directed to a wastegate actuator, other vacuum consumers can receive vacuum in addition to or as an alternative to the wastegate actuator. Examples of vacuum consumers include a brake booster for the vehicle's braking system, a charge motion control valve, a fuel vapor reservoir (to provide vacuum for purging fuel vapors from the reservoir), and other vacuum-consuming devices.

[0028] Thus, the systems of Fig. 1 and Fig. 2. A system for an engine comprising a compressor coupled to a turbine; a second ejector positioned in a bypass path of the compressor; a turbine wastegate valve actuated by a vacuum actuator; and a vacuum duct coupling the second ejector to the vacuum actuator. The system may include a vent line coupling the vacuum line to an inlet duct upstream of the compressor. A vent valve may be positioned in the vent line, and the system may include a control unit providing instructions for adjusting the vent valve based on the target boost pressure.

[0029] The system may include a first ejector positioned above a throttle and flow-coupled to the vacuum channel. A valve may be positioned in the compressor bypass path. In one example of the system, a controller may provide instructions to open the valve based on air mass and compressor pressure ratio. In another example, the controller may provide instructions to open the valve based on the target boost pressure. A compressor bypass valve may be positioned parallel to the first ejector.

[0030] Fig. Figure 3 shows another embodiment of a system for actuating a wastegate valve with a vacuum-operated actuator. The Fig. The system shown in section 3 uses a vacuum generated by an engine exhaust to control a wastegate actuator instead of a vacuum generated by the compressor bypass flow, as in the systems described below. Fig. 1 and Fig. 2. Fig. Figure 3 shows an engine system 300. The engine system 300 is similar to engine systems 10 and 200 in that it includes an engine 12, a compressor 90, a turbine 92, a wastegate 42, and a wastegate actuator 44, as well as other components described previously. In the engine system 300, a vacuum is supplied to the wastegate actuator 44 by an ejector 302 positioned in an exhaust gas flow path. As shown, the ejector 302 is positioned in a bypass channel 304 that runs parallel to the bypass channel 40. However, in some embodiments, the ejector 302 can be positioned in the bypass channel 40. Thus, the ejector 302 receives exhaust gas flowing from the engine 12 and discharges the exhaust gas to the outlet channel 35 downstream of the turbine 92. The vacuum generated by the ejector 302 is directed via channel 306 to the wastegate actuator 44.As the exhaust gas flow from the engine increases, thereby increasing the turbine speed and thus the boost pressure, the vacuum level supplied to the wastegate actuator 44 by the ejector 302 also increases.

[0031] In this way, exhaust pressure can be used as actuation pressure without placing the wastegate actuator in the exhaust flow path, where it would be exposed to intense heat and thus damage the actuator's diaphragm and / or compressed air hose. In the Fig. In the configuration shown in Figure 3, the boost pressure provides both the signal to open the wastegate and the mechanism to generate the vacuum to open the wastegate.

[0032] Although the ejector in the representation of Fig. While the ejector is coupled via the turbine (3), with the turbine inlet acting as a high-pressure source and the turbine outlet as a low-pressure sink, other configurations are also possible. For example, the ejector can receive high-pressure air from the turbine inlet and deliver air to the compressor inlet. In another example, the ejector can receive air from the turbine outlet and deliver air downstream of the catalyst or to the compressor inlet.

[0033] To provide controllability of the wastegate actuation, a vent valve can be arranged between the wastegate actuator 44 and the ejector 302. In a "vacuum" position, the valve can apply the full vacuum of the ejector 302. In the "vent" position, the valve can establish atmospheric pressure on either side of the vacuum actuator 44. The vent valve can always vent a portion of the flow in any position except at full vacuum. In other examples, the vent valve can have three modes: increase vacuum, vent vacuum, and maintain current vacuum. In all cases, this valve allows control via the controller rather than strictly via pneumatic-mechanical settings.

[0034] Fig. 4 represents the vacuum generation system of Fig. 3 with optional active charge control and wastegate actuation under low or no charge conditions. Fig. Figure 4 represents an exemplary engine system 400, which, in addition to other components already described, includes the wastegate actuator 44 and the ejector 302. Fig. 3 contains. Channel 306, which couples the ejector 302 to the wastegate actuator 44, extends the entire length from the ejector 302 to the wastegate actuator 44, with additional lines and channels, explained below, intersecting and coupling to channel 306.

[0035] Vacuum can be supplied to reservoir 416 from four separate sources: ejectors 302, 410, 406, and the intake manifold. Other ejector-based sources are also possible.

[0036] The ejector 302 introduces air into the exhaust stream. This is advantageous in certain cases, for example, when the catalytic converter starts up, where it can act as a secondary air injection pump. Another case is during rich operation, where the added air reduces regulated emissions, albeit at the cost of increased catalytic converter heat.

[0037] To provide active boost control via actuation of the wastegate 42, a vent line 402 can be provided to couple the channel 306 with the inlet channel 18 upstream of the compressor 90. A vent valve 404 can be positioned in the vent line 402 or at the intersection of the vent line 402 with the channel 306. The vent valve 404 can be controlled by the controller 50 to adjust the vacuum level supplied to the wastegate actuator 44, with excess vacuum being routed back to the inlet via the vent line 402. Thus, active boost pressure control can be provided by controlling the vent valve 404.

[0038] To open the wastegate 42 under low or no boost conditions (for example, when insufficient vacuum is generated via the ejector 302), vacuum can be routed from the intake manifold 24 to the wastegate actuator 44. To provide intake manifold vacuum, a second ejector 406 can be coupled via the throttle 22. The second ejector 406 can generate vacuum from the intake air flow from upstream of the throttle to downstream of the throttle. The vacuum generated by the second ejector 406 can be routed to channel 306 and / or through the vent valve 404. Flow control through the second ejector 406 can be provided by the ejector flow control valve 408.

[0039] In some embodiments, a third ejector 410 similar to the one above can be provided in the compressor bypass flow channel with reference to the Fig. 1 and Fig. The ejector 80 described in section 2 may be provided. The vacuum from the third ejector 410 can be routed to the channel 306 via the channel 412. To control the airflow through the third ejector 410, an ejector drive flow control valve 414 may be provided in the bypass channel where the third ejector 410 is located.

[0040] A vacuum reservoir 416 can be flow-coupled with the ejector 302, the second ejector 406, the third ejector 410, and the wastegate actuator 44. As shown in Fig. As shown in Figure 4, a channel from reservoir 416, a channel 412 from the third ejector 410, and a channel from the second ejector 406 intersect with channel 306 and are thus flow-coupled. This allows negative pressure from reservoir 416, third ejector 410, and / or second ejector 406 to be directed to the wastegate actuator 44. In this way, negative pressure can be stored in reservoir 416 and applied to the wastegate actuator 44 if the pressure drop at ejector 302, third ejector 410, and / or second ejector 406 is insufficient to control the position of the wastegate 42. Furthermore, a first check valve 418, a second check valve 420 and a third check valve 422 can prevent vacuum relief from the accumulator 416 and / or ensure that vacuum flows only from the ejector 302, second ejector 406 or third ejector 410 to the wastegate actuator 44 and not in the other direction.Similar to the previous figures, airflow through the various channels and passages of the 400 engine system is shown by the arrows. Fig. 3 shown.

[0041] Under conditions of high intake manifold vacuum, airflow through the second ejector 406 to generate sufficient vacuum to actuate the wastegate 42 may not be necessary. Therefore, a direct channel 424 can couple the intake channel 18 upstream of the intake manifold 24 to the channel 306. A fourth check valve 426 may be provided in the direct channel 424.

[0042] The in Fig. The configuration shown is not restrictive, as other configurations are also possible. For example, memory 416 can be omitted. Likewise, the second ejector 406 and / or the third ejector 410 can be omitted. Although the Fig. 3 and Fig. In addition to or as an alternative to the wastegate actuator, other vacuum consumers can also receive the vacuum generated by the ejector in the exhaust flow path and / or from the intake manifold. Examples of vacuum consumers include a brake booster for the vehicle's braking system, a charge motion control valve, a fuel vapor reservoir (for supplying vacuum to purge fuel vapors from the reservoir), and other vacuum-consuming devices.

[0043] The in the Fig. 3 and Fig. The four illustrated systems provide a system for an engine comprising a compressor positioned in an engine inlet and coupled to a turbine positioned in an engine outlet; an ejector positioned in an exhaust flow path; a turbine wastegate valve actuated by a vacuum actuator; and a vacuum channel coupling the ejector to the vacuum actuator. An ejector inlet may be positioned upstream of the turbine in the exhaust flow path, and an ejector outlet may be positioned downstream of the turbine in the exhaust flow path. In other examples, the ejector inlet may be positioned upstream of the turbine in the exhaust flow path, and the ejector outlet may be positioned upstream of the compressor in an inlet.

[0044] Furthermore, the system may include a vent line that couples the vacuum duct to an inlet duct upstream of the compressor. A vent valve may be positioned in the vent line, and a controller may provide instructions for adjusting the vent valve based on the target boost pressure. The system may include a second ejector positioned above a throttle and flow-coupled to the vacuum duct. A third ejector may be positioned above the compressor and flow-coupled to the vacuum duct.

[0045] Thus, the in the Fig. 1 and Fig. 2 provided systems actuate a wastegate with negative pressure generated by a second ejector positioned in a compressor bypass flow path, while the systems of the Fig. 3 and Fig. 4. Ensure wastegate actuation by means of a vacuum generated by an ejector positioned in an exhaust gas flow path. Each wastegate actuation system may include a vent line, and the vent valve is controllable by the controller to supply a selected vacuum level to the actuator, thereby providing boost control. Furthermore, each actuation system may include an additional vacuum source derived from the intake manifold vacuum to supply vacuum to the actuator under low or no boost conditions.

[0046] Fig. 5 represents a method 500 for supplying negative pressure to a negative pressure actuator, such as the wastegate actuator 44 of the Fig. 1-4, represented. Procedure 500 can be carried out by the controller 50 according to the instructions stored therein. Procedure 500 includes, at 502, determining operating parameters. The operating parameters may include engine speed and load, boost pressure (as determined by compressor inlet pressure (CIP), throttle inlet pressure (TIP), and / or MAP), and other parameters. At 504, it is determined whether the engine is operating with forced induction (for example, MAP greater than barometric pressure). If the engine is not operating with forced induction, which may occur, for example, during low-load operation, procedure 500 proceeds to 506 to open a wastegate positioned above a turbocharger turbine by applying a vacuum to the wastegate actuator. As shown at 508, the vacuum can be drawn from the intake manifold, for example, by opening valve 208 of Fig. 2 or opening valve 408 of Fig. 4. The vacuum is directed to the wastegate actuator. The vacuum can be supplied directly from the intake manifold (or intake port upstream of the manifold and downstream of the throttle), or it can be generated by directing the intake air through an ejector coupled via the throttle. In some examples, however, vacuum may be supplied from a vacuum reservoir instead of the intake manifold. Opening the wastegate even under no-boost conditions can reduce pumping losses by the turbine, thereby increasing fuel economy. Then the process returns to step 500.

[0047] If procedure 504 determines that the engine is operating with turbocharging, procedure 500 proceeds to 510 to determine whether a target boost level differs from a planned boost level. The target boost level might, for example, be based on engine speed and load. If the target boost level and the planned boost level do not differ, no settings for the current wastegate position are displayed, and thus procedure 500 proceeds to 512 to maintain the current operating parameters (for example, maintain the current wastegate position), and then procedure 500 returns.

[0048] Returning to 510, if the target boost pressure and the intended boost pressure differ, procedure 500 proceeds to 514 to adjust the wastegate position by applying a vacuum to the wastegate actuator. To apply the vacuum at 516, the position of the vent valve can be adjusted to supply a target vacuum level to the wastegate actuator to adjust the wastegate position. The target vacuum level can be based on the target boost pressure. Depending on the configuration of the actuation system, the vacuum can be supplied to the wastegate actuator from various sources. As shown in 518, vacuum can be routed from the compressor bypass flow path to the actuator if the boost pressure is relatively high and / or the intake manifold vacuum is relatively low.Furthermore, in some examples, the ejector drive flow control valve in the compressor bypass flow can be opened to supply the drive flow through the second ejector to generate the vacuum. If the second ejector is positioned in the compressor bypass flow, as in the... Fig. 1 and Fig. As shown in Figure 2, the vacuum can be generated by the second ejector when the boost pressure exceeds a threshold. The threshold boost pressure can be zero, so that vacuum is supplied to the actuator whenever boost is available. In other embodiments, the threshold can be the target boost pressure, and if excess boost above the target is available, vacuum can be generated by the second ejector and supplied to the actuator. In still other embodiments, the threshold can be a fixed boost pressure that provides sufficient vacuum generation to actuate the wastegate. The generation of vacuum by the compressor bypass ejector can be actively controlled by opening valve 86, or it can occur passively when the available boost exceeds the target boost pressure.Furthermore, the wastegate position can be selected to maintain a certain amount of excess boost to generate the vacuum. In other examples, the wastegate position can be selected to bring the supplied boost up to the target boost level, even if no excess boost is subsequently available to generate the vacuum.

[0049] If the ejector is positioned in the exhaust stream, as in the Fig. 3 and Fig. As shown in Figure 4, vacuum can be routed from the exhaust gas stream to the actuator when the boost pressure is high and / or the intake manifold vacuum is low, as shown in Figure 520. The conditions for routing vacuum from the exhaust gas stream may be similar to those for routing vacuum from the compressor bypass stream in that sufficient boost pressure must be available to generate the vacuum. Furthermore, in some examples, the ejector drive flow control valve in the exhaust gas stream path may be opened to provide drive flow through the ejector to generate the vacuum.

[0050] If the boost pressure is too low to generate sufficient vacuum (for both the compressor bypass ejector and the exhaust ejector), and if the intake manifold vacuum is high, vacuum can be routed from the intake manifold to the actuator, as shown in 592. Routed vacuum from the intake manifold may be similar to that described above in 506 and 508. However, in some embodiments, the vacuum may be routed from a vacuum reservoir instead of the intake manifold.

[0051] Thus, the procedure represents 500 of Fig. 5. Actuation of a wastegate using a vacuum actuator is provided under both higher and lower boost conditions. In one example, a method for an engine containing a turbocharger with a turbine-driven compressor involves generating a vacuum via the compressor bypass flow through a second ejector and applying the vacuum from the second ejector to a wastegate actuator. Another method for an engine containing a turbocharger with a turbine-driven compressor involves generating a vacuum via the exhaust flow through an ejector and applying the vacuum from the ejector to a wastegate actuator.

[0052] For both methods, the wastegate actuator can be configured to adjust a turbine wastegate valve. The vacuum from the second ejector to the wastegate actuator can be supplied via a channel that establishes flow coupling between the second ejector and the wastegate actuator, and a vent line can establish flow coupling between the channel and an inlet duct upstream of the compressor.

[0053] Furthermore, the methods may include adjusting the boost pressure by adjusting a valve positioned in the ventilation duct. The methods may also include applying a vacuum from an intake manifold of the engine to the wastegate actuator. Applying a vacuum from the intake manifold of the engine to the wastegate actuator may further include generating a vacuum via a first ejector positioned in the intake airflow path. The methods may include storing the vacuum generated by the second ejector and / or the first ejector in a vacuum reservoir.

[0054] In another example, a method for an engine incorporating a turbocharger with a turbine-driven compressor includes, under a first condition, adjusting a turbine wastegate valve via a vacuum actuator, wherein vacuum is received from a second ejector positioned in a compressor bypass flow path, and under a second condition, adjusting the wastegate valve via the vacuum actuator, wherein vacuum is received from an engine intake manifold.An additional method for an engine incorporating a turbocharger with a turbine-driven compressor comprises, under a first condition, adjusting a turbine wastegate valve via a vacuum actuator, wherein vacuum is received from an ejector positioned in an exhaust flow path, and under a second condition, adjusting the wastegate valve via the vacuum actuator, wherein vacuum is received from an intake manifold of the engine.

[0055] In the procedures, the first condition may be that the boost pressure is above a threshold, and the second condition may be that the boost pressure is below the threshold. In another example of the procedures, the first condition may be that the intake manifold vacuum is below a threshold, and the second condition may be that the intake manifold vacuum is above the threshold.

[0056] Furthermore, the methods may include adjusting the boost pressure by adjusting a vent valve positioned in a vent line that establishes flow coupling between the second ejector and an intake port upstream of the compressor. Adjusting the wastegate valve via the vacuum actuator with vacuum received from the intake manifold may also include adjusting the wastegate valve via the vacuum actuator with vacuum received from a first ejector positioned above a throttle on the intake manifold.

[0057] A drive control valve in the exhaust gas flow path can be opened to create a vacuum from the ejector when the ejector is positioned in the exhaust gas flow path. If the ejector is positioned in the compressor bypass flow path, a drive control valve in the compressor bypass flow path can be opened to create a vacuum from the ejector.

[0058] Briefly again Fig. 2 With reference to this, the two can be in Fig. The two ejectors shown (second ejector 80 and first ejector 206) receive motive flow, which is controlled by two separate valves (motive flow control valve 86 and motive flow control valve 208), each having its own separate actuators to allow independent control of the motive flow by each ejector. However, such actuators can be expensive. Furthermore, in typical ejector systems, air leaving the ejector is routed to one or more low-pressure sinks (for example, the intake manifold) via high-flow check valves, which are also expensive. To avoid the use of high-flow check valves in the motive flow path, multiple ejectors can be used (for example, one ejector for each low-pressure sink), as shown in Fig. Figure 2 shows that a single actuator can be used to control the position of both traction control valves. Such a configuration is described below. Fig. 6 and Fig. 7 shown.

[0059] Fig. Figure 6 shows an engine system 600, which includes an intake manifold 24, a compressor 90, a throttle 22 and other components described in the previous figures. Although this in Fig. The intake manifold 24, which is not shown in figure 6, is similar to the one in the Fig. The intake manifold shown in Figures 1-4 is coupled to an engine. The engine system 600 contains two ejectors, a first ejector 602 and a second ejector 604. The first ejector is positioned in a bypass channel 606, which is coupled to the intake channel via the throttle 22. Air enters the bypass channel from upstream of the intercooler 26 (although alternatively it can enter from downstream of the intercooler 26 and upstream of the throttle), flows through the first ejector 602, and exits to the intake manifold 24. A first drive flow control valve 608 is positioned in the bypass channel 606.

[0060] The second ejector 604 is positioned in the bypass channel 610, which bypasses the compressor 90. Air enters the bypass channel 610 from the compressor outlet, flows through the second ejector 604, and exits at the compressor inlet. A second drive flow control valve 612 is positioned in the bypass channel 610. Although Fig. In Figure 6, a separate compressor bypass valve 30 is provided for controlling the flow around the compressor. In some embodiments, the compressor bypass valve can be replaced by the second drive flow control valve 612. As discussed previously, the compressor bypass valve 30 can provide boost control as well as pumping protection. Compressor pumping occurs under conditions of high boost pressure (for example, a high pressure ratio at the compressor) and low airflow through the compressor; compressor pumping can, under some conditions, lead to damage to the turbocharger components. Thus, to reduce pumping, air from the compressor outlet can be recirculated back to the compressor inlet via the compressor bypass valve, thereby increasing the flow through the compressor and reducing pumping. Alternatively, cooled air downstream of the charge air cooler can be circulated around the compressor to improve the pumping reserve.If the compressor bypass valve 30 is omitted, the second valve 612 can act as a pump reserve valve, which opens under pumping conditions to ensure pump protection. Under turbocharger high-speed conditions, such as during vehicle acceleration, the second valve 612 can be closed. By replacing the continuously variable compressor bypass valve with the second on / off valve 612, the turbocharger high-speed operation caused by the "permanent leak" introduced by the continuously variable compressor bypass valve can be reduced.

[0061] The first valve 608 and the second valve 612 can be actuated by a common actuator 614. The actuator 614 can be an electromagnetic actuator that is activated upon receiving power from the controller 50. The actuator 614 can have a default position, which it assumes when it is not activated. In the default position, one of the valves can be closed while the other is open. In the activated position, the closed valve opens and the open valve closes. For example, when the actuator is in the default position, the first valve 608 can be open while the second valve 612 is closed. In the activated position, the first valve 608 can close while the second valve 612 opens. In this way, a single actuator can be used to control the position of several flow control valves. Fig. Figure 6 shows valves 608 and 612 as inline valves, but other valve configurations are also possible. For example, the valves can be spool valves positioned at the necks of the ejectors. Furthermore, the control line between actuator 614 and valves 608 and 612, through which actuator 614 adjusts the position of the valves, is shown in Figure 6. Fig. 6 shown as dotted lines.

[0062] The first ejector 602 and the second ejector 604 can each direct vacuum to a vacuum reservoir 616, which can be coupled to one or more vacuum consumers 618 and 620. The vacuum consumers can be suitable devices that use vacuum, such as pneumatic actuators (the wastegate actuator, the charge motion control actuator, the brake booster, the engine mount, the front axle disconnect, HVAC controls, etc.) and / or gas intake systems / devices (for example, for the intake of gaseous fuel, crankcase gases, recirculated exhaust gas, and fuel vapors).

[0063] Although Fig. Figure 6 shows two valves actuated by a single actuator; in some embodiments, the two valves can be replaced by a single valve. As shown in Fig. Figure 7 shows an engine system 700, similar to system 600, with bypass channels 606 and 610 sharing a common inlet line 702 leading to a valve 704. The valve 704 can be actuated into one of two positions by an actuator. When the actuator is in a first position, the standard position, the valve 704 can be in a first position in which air from the inlet line 702 is directed through the first ejector 602. When the actuator is in a second, activated position, the valve 704 can be moved into a second position in which air from the inlet line 702 can be directed through the second ejector 604.

[0064] The two Fig. 6 and Fig. Figure 7 shows a coordinated control of the airflow through both ejectors, such that if air flows through one ejector, it does not flow through the other. Since one ejector receives driving current under conditions of high boost (the second ejector 604), while the other receives driving current under conditions of high intake manifold vacuum T, the vacuum generation by the ejectors can occur under most operating conditions and can be just as effective as if the ejectors were controlled independently.

[0065] The systems of Fig. 6 and Fig. 7. Provides a system for an engine comprising a first ejector positioned above a throttle and controlled by a first valve; a second ejector positioned in a compressor bypass stream and controlled by a second valve; and a common actuator configured to simultaneously set the position of the first and second valves. The second valve may include a continuously variable compressor bypass valve. The system may include a controller with instructions to activate the common actuator to open the second valve and close the first valve when boost pressure exceeds a threshold.The control system can also include instructions to activate the common actuator to open the second valve and close the first valve in response to compressor operation in a pumping range where the compressor pressure ratio is above a threshold and the compressor flow rate is below a threshold. The control system can also include instructions to activate the common actuator to close the second valve and open the first valve in response to turbocharger lag where the target boost to meet engine power demands exceeds the provided boost by more than a threshold.

[0066] Now on Fig. With reference to paragraph 8, a method 800 for generating a vacuum is described using multiple ejectors having separate drive flow control valves actuated by a common actuator. The method 800 can be carried out by a controller 50 according to instructions stored therein to generate a vacuum in the engine system 600. Fig. 6 or in the 700 engine system from Fig. 7. Method 800 comprises generating a vacuum via a first ejector with an actuator (for example, actuator 614) in a first position, the standard position. As explained previously, the actuator can have a standard position, which it assumes when not activated. The first ejector can be positioned in an inlet airflow path via a throttle, such as first ejector 602. As shown in 804, inlet air flows through the first ejector to generate the vacuum. With the actuator in the first position, a first drive flow control valve (for example, first valve 608) is also open, and a second drive flow control valve (for example, second valve 612) is closed, as shown in 806. Thus, with the actuator in the first position, air flows through the first valve to the first ejector, but does not flow through the second valve to the second ejector.

[0067] Procedure 808 determines the engine operating parameters. These parameters may include boost pressure, engine speed and load, MAP (manifold absolute pressure), and other parameters. Procedure 810 determines whether the boost pressure is above a threshold. The threshold boost pressure may be no boost, so any boost above the threshold is acceptable. In other embodiments, the threshold may be the target boost, or it may be a specified boost level. If the boost pressure is above the threshold, Procedure 800 proceeds to 816, which is explained below. If the boost pressure is not above the threshold, Procedure 800 proceeds to 812 to hold the actuator in the default position, as there is insufficient boost pressure to generate vacuum with the second ejector.

[0068] Procedure 800 transitions to 814 to determine whether the compressor is currently operating or its operation is predicted to occur in a pumping range. Compressor pumping can result from low airflow through the compressor; under certain conditions, such as a driver tip-out event, the flow and pressure ratio across the compressor can fluctuate to levels that can cause noise disturbances and, in more severe cases, performance problems and compressor impairment. To mitigate such pumping events, if the second valve has replaced the CBV, it can be opened to increase flow through the compressor. As used here, the term "pumping range" includes compressor operating points that result in pumping (for example, above a pumping head) as well as operating points near a pumping head that do not result in pumping (but which may cause compressor pumping if small airflow fluctuations occur).Furthermore, the compressor can be considered to be operating in the pumping range if it is predicted that the compressor would pump at or during the transition to the next requested operating point.

[0069] The compressor's pumping range is a function of the compressor pressure ratio (for example, the boost pressure) and the airflow through the compressor. The pressure ratio and the airflow through the compressor can be mapped onto a compressor operating map, which indicates when the compressor is pumping. Alternatively, compressor operation in the pumping range can be determined based on engine speed and load. Even if the compressor is not currently pumping, subsequent pumping operation can be predicted based on the next requested operating point. For example, if a tip-out event or another drop in engine speed or load has occurred, it can be predicted that the airflow through the compressor is about to decrease, and thus it can be estimated that the compressor will operate in the pumping range.

[0070] If the compressor is not operating in the pumping range (or its operation in the pumping range is not predicted), procedure 800 reverts to 812 to maintain the actuator's default position. If the compressor is operating in the pumping range or its operation there is predicted, procedure 800 reverts to 816 to activate the actuator's solenoid to set the actuator to a second position and generate a vacuum through a second ejector (for example, the second ejector 604). Furthermore, if, as explained above, it is determined at 810 that the boost pressure is above the threshold, procedure 800 also reverts to 816 to activate the solenoid.

[0071] With the solenoid activated and the actuator in the second position, compressor bypass air flows through the second ejector to create the vacuum, as shown in Figure 818. To direct air through the second ejector, the actuator opens the second valve and closes the first valve, as shown in Figure 820.

[0072] At 822, it is determined whether the boost pressure falls below the threshold or whether turbocharger lag is detected. Turbocharger lag refers to a condition in which the amount of boost supplied is insufficient to meet the engine's power requirements and can occur during a tip-in event or vehicle acceleration. Turbocharger lag can cause a temporary, undesirable delay in engine power that is noticeable to a driver. To reduce turbocharger lag, all exhaust gas in the exhaust port can be routed through the turbine to quickly bring the turbine up to the required speed and thus generate the requested boost, and all intake air can be routed through the compressor.If turbocharger delay is detected (or if imminent turbocharger delay is predicted) or if the boost pressure has dropped below the threshold, procedure 800 thus proceeds to 824 to deactivate the solenoid and return the actuator to its standard position.

[0073] Although the procedure 800 of Fig. Figure 8 describes the control of two ejectors by two valves with a single actuator; alternatively, the two ejectors can be controlled by a single valve, as in Fig. Figure 7 shows that in such a configuration, the actuator can move the valve between a first position, in which the first ejector is used to generate a vacuum, and a second position, in which the second ejector is used to generate a vacuum.

[0074] The Fig. 9 and Fig. Figure 10 represents exemplary engine operating conditions with coordinated control of the two ejector drive current control valves. Fig. Figure 9 represents a diagram 900, which shows operating conditions under a steady-state driving condition, with a vehicle traveling at constant engine power. Curve 902 represents the throttle inlet pressure (TIP), curve 904 represents the MAP, and curve 906 represents the barometric pressure, with time on the horizontal axis and pressure force on the vertical axis. When TIP is higher than MAP, more efficient vacuum generation can occur with the second ejector, and thus, as shown by curve 910, the second valve is open for most of the time shown in diagram 900. However, between times t1 and t2, TIP and MAP can close to such an extent that vacuum generation by the first ejector is favored, and thus the first valve, shown by curve 908, is open during this time.As shown by curves 908 and 910, the second valve is closed when the first valve is open, and when the first valve is closed, the second valve is open.

[0075] Fig. Figure 10 represents a diagram 1000, which has the same operating parameters as Fig. Figure 9 shows the situation during an acceleration event where the engine power demand is at or above the supplied airflow. TIP is represented by curve 1002, MAP by curve 1004, BP by curve 1006, the first valve position by curve 1008, and the second valve position by curve 1010. Before time t1, TIP is greater than MAP, and thus the second valve can be open when the first valve is closed. After time t1, however, TIP is close to or at MAP, and thus the first valve is open and the second valve is closed.

[0076] The systems and methods described here thus provide a process which, when the boost pressure is below a threshold, involves generating a vacuum with an actuator in a first position by directing air from a compressor outlet to an inlet manifold through a first ejector, and, when the boost pressure is above the threshold, involves generating a vacuum with the actuator in a second position by directing air from the compressor outlet to a compressor inlet through a second ejector. Generating a vacuum with the actuator in the first position may further include opening a first valve and closing a second valve with the actuator to direct air through the first ejector. Generating a vacuum with the actuator in the second position may further include closing the first valve and opening the second valve with the actuator to direct air through the second ejector.

[0077] Furthermore, the method can include, in response to actual or predicted compressor operation in a pumping range, closing the first valve and opening the second valve with the actuator, and directing air from the compressor outlet to the compressor inlet through the second ejector. Additionally, in response to actual or predicted turbocharger delay, the method can include opening the first valve and closing the second valve with the actuator. Vacuum generated by the first ejector and vacuum generated by the second ejector can be directed to a vacuum actuator. The vacuum actuator can include a wastegate actuator and / or a brake booster and / or a charge motion control valve. The vacuum generated by the first ejector and vacuum generated by the second ejector can be directed to an engine gas intake device.The engine gas intake device may include a fuel vapor reservoir and / or an engine crankcase and / or an intake manifold.

[0078] In another example, a method comprises, under a first condition, generating a vacuum over a first ejector by opening a first valve and closing a second valve with a common actuator and directing air from a compressor outlet to an inlet manifold through the first ejector, and under a second condition, generating a vacuum over a second ejector by closing the first valve and opening the second valve with the common actuator and directing air from the compressor outlet to a compressor inlet through the second ejector.

[0079] In one example, the first condition might be that the boost pressure is above a threshold, and the second condition might be that the boost pressure is below the threshold. In another example, the first condition might be that the compressor is currently or predicted to be operating in the pumping range, and the second condition might be that the turbocharger is currently or predicted to be delayed. Furthermore, the method might include determining whether the compressor is currently or predicted to be operating in the pumping range based on the air mass rate and a level of boost applied. The current or predicted turbocharger delay could be determined based on the difference between the target boost pressure and the actual boost pressure.The method may include directing the vacuum generated by the first ejector and the vacuum generated by the second ejector to a vacuum reservoir, wherein the vacuum reservoir is coupled to one or more vacuum consumers.

[0080] It is understood that the configurations and methods disclosed herein are purely exemplary and that these particular embodiments should not be considered limiting, as numerous variations are possible. The above technology can, for example, be applied to V-6, I-4, I-6, V-12, Boxer-4, and other engine types. The subject matter of this disclosure thus includes all new and non-obvious combinations and sub-combinations of the various systems and configurations and other features, functions, and / or properties disclosed herein.

[0081] The following claims specifically indicate certain combinations and subcombinations that are considered novel and not obvious. These claims may refer to "one" element, "a first" element, or the equivalent thereof. Such claims should be understood as encompassing one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements, and / or properties may be claimed by amending the present claims or by filing new claims in this or a related application. Such claims, whether their scope of protection is broader, narrower, the same, or different with respect to the original claims, shall also be considered to be included in the subject matter of the present disclosure.

Claims

[1] System (200) for a motor (12), comprising: - an engine inlet (23) with an air inlet throttle (22) which is flow-coupled with an engine inlet manifold (24) along an inlet channel (18), and a compressor (90) for charging an inlet air charge received along the inlet channel (18); - a first ejector (206) positioned above the air inlet throttle (22) and controlled by a first valve (208); - a second ejector (80) positioned in a compressor bypass stream and controlled by a second valve (86); - a common actuator (44) configured to simultaneously adjust a position of the first valve (208) and the second valve (86); and - a channel (84) connecting the second ejector (80) to the actuator (44), which is designed to direct the negative pressure generated by the second ejector (80) to the actuator (44); - a ventilation duct (202) that connects the duct (84) upstream of the compressor (90) to the inlet duct (18); and - a ventilation valve (204) positioned in the ventilation duct (202) or at an intersection of the ventilation duct (202) with the channel (84). [2] System (200) according to claim 1, wherein the second valve (86) comprises a continuously adjustable compressor bypass valve. [3] System (200) according to claim 1 or 2, further comprising a control (50) with instructions for activating the common actuator (44) to open the second valve (86) and close the first valve (206) when the boost pressure is above a threshold value. [4] System (200) according to any one of claims 1 to 3, further comprising a control (50) with instructions for activating the common actuator (44) to open the second valve (86) and close the first valve (208) in response to compressor operation in a pumping area. [5] System (200) according to any one of claims 1 to 4, further comprising a control (50) with instructions for activating the common actuator (44) to close the second valve (86) and open the first valve (208) in response to a turbocharger delay. [6] Method (500) in which a system (200) according to any one of claims 1 to 5 is operated, the method (500) comprising: when charging is below a threshold value, generating a vacuum with the actuator (44) in the first position by directing air from a compressor outlet to the engine intake manifold (24) through the first ejector (206); and, When charging is above the threshold, a vacuum is generated with the actuator (44) in a second position by directing air from the compressor outlet to a compressor inlet through the second ejector (80). [7] Method (500) according to claim 6, wherein generating a vacuum with the actuator (44) in the first position further comprises opening the first valve (208) and closing the second valve (86) with the actuator (44) to direct air through the first ejector (206). [8] Method (500) according to claim 7, wherein generating a vacuum with the actuator (44) in the second position further comprises closing the first valve (208) and opening the second valve (86) with the actuator (44) to direct air through the second ejector (80). [9] Method (500) according to claim 8, further comprising, in response to actual or predicted compressor operation in a pumping area, closing the first valve (208) and opening the second valve (86) with the actuator (44) and directing air from the compressor outlet to the compressor inlet through the second ejector (80). [10] Method (500) according to claim 9, further comprising opening the first valve (208) and closing the second valve (86) with the actuator (44) in response to actual or predicted turbocharger delay. [11] Method (500) according to any one of claims 6 to 10, further comprising directing vacuum generated by the first ejector (206) and vacuum generated by the second ejector (80) to a vacuum actuator. [12] Method (500) according to claim 11, wherein the vacuum actuator comprises a wastegate actuator and / or a brake booster and / or a charge motion control valve. [13] Method (500) according to any one of claims 6 to 12, further comprising directing vacuum generated by the first ejector (206) and vacuum generated by the second ejector (80) to an engine gas inlet device. [14] Method (500) according to claim 13, wherein the engine gas inlet device comprises a fuel vapor reservoir and / or an engine crankcase and / or an inlet manifold. [15] Method (500) in which a system (200) according to any one of claims 1 to 5 is operated, the method (500) comprising: under a first condition, generating a vacuum via the first ejector (206) by opening a first valve (208) and closing a second valve (86) with the common actuator (44) and directing air from a compressor outlet to the engine intake manifold (24) through the first ejector (206); and Under a second condition, a vacuum is generated via a second ejector (80) by closing the first valve (208) and opening the second valve (86) with the common actuator (44) and directing air from the compressor outlet to a compressor inlet through the second ejector (80). [16] Method (500) according to claim 15, wherein the first condition comprises that a boost pressure is above a threshold value, and wherein the second condition comprises that the boost pressure is below the threshold value. [17] Method (500) according to claim 15 or 16, wherein the first condition comprises actual or predicted compressor operation in a pumping area and the second condition comprises actual or predicted turbocharger delay. [18] Method (500) according to claim 17, further comprising determining whether the current or predicted compressor operation is in the pumping range, based on the air mass rate and a level of supplied charging. [19] Method (500) according to claim 17, wherein the actual or predicted turbocharger delay is determined based on a difference between the target boost pressure and the actual boost pressure. [20] Method (500) according to any one of claims 15 to 19, further comprising directing the vacuum generated by the first ejector (206) and the vacuum generated by the second ejector (80) to a vacuum reservoir (210), wherein the vacuum reservoir (210) is coupled to one or more vacuum consumers.

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