Abstract:
In some examples, reduced engine displacement reduces an engine&#39;s ability to provide brake booster vacuum. The present application relates to intake systems including a vacuum aspirator to generate vacuum.

Description:
TECHNICAL FIELD  
       [0001]    The present application relates to intake systems including a vacuum aspirator, for generating vacuum for use in a brake booster, for example. 
       BACKGROUND AND SUMMARY  
       [0002]    Spark-ignited vehicles may use intake manifold vacuum to provide brake boost or power assist. Engine downsizing reduces the ability of these engines to provide brake booster vacuum. One existing solution is to add a vacuum pump, however the vacuum pump leads to parasitic fuel economy losses and increases overall vehicle cost. 
         [0003]    In one approach described in U.S. Pat. No. 7,610,140, a vehicle ejector system has an ejector, a state change device that causes the ejector to function or stop functioning, and a control device that controls the state change device (Summary). “Furthermore . . . the control device may include a control prohibition portion that prohibits the control device from controlling the state change device so as to cause the ejector to function if water temperature of a cooling water of the internal combustion engine is less than or equal to a predetermined temperature” (col. 4 ll. 8-13). 
         [0004]    The inventors herein recognize various issues with the above described approaches. During cold start, engine conditions (such as high manifold air pressure and low barometric pressure due to low temperature and/or high altitude) may limit the available vacuum for various engine systems, such as the brake booster. In downsized engines including a supercharger and/or turbocharger, boosting may further reduce the conditions under which brake vacuum is available. Further, as a range of cylinder pressures increase, so does a range of intake passage pressures increase. Intake systems including a single fixed geometry aspirator may function inefficiently or not at all at some pressures of the increased pressure range. 
         [0005]    Consequently, methods, systems and devices for a vacuum aspirator included in an intake system are described. In a first example, an intake system includes an intake passage including a compressor, a throttle and an intake manifold, and an aspirator having a motive inlet communicating with the intake passage intermediate to the compressor and the throttle and the aspirator having an entraining inlet communicating with a vacuum reservoir via a first check valve, the reservoir different from the intake manifold, and the first check valve limiting flow from the intake passage to the vacuum reservoir. 
         [0006]    In a second example, an intake system includes, a throttle, the throttle including a first inlet, a second inlet, and a plate, the plate located intermediate the first inlet and the outlet, the second inlet located intermediate to the throttle plate and the first inlet, the throttle positioned in an intake passage, and an aspirator having a motive inlet in communication with the intake passage, the aspirator having an outlet in communication with the second inlet of the throttle, the aspirator having an entraining inlet in communication with a vacuum reservoir via a first check valve, the first check valve limiting flow from the second inlet to the vacuum reservoir. 
         [0007]    In a third example, an intake system having a plurality of vacuum boosters for a vacuum reservoir, includes a first aspirator having a first motive inlet, first entraining inlet, and first outlet, the first motive inlet in communication with an intake passage adjacent a high pressure outlet of a compressor, and a second aspirator having a second motive inlet, second entraining inlet, second outlet, and second check valve, where either the second outlet is in communication with the first entraining inlet or the second motive inlet is in communication with the first outlet, and the second entraining inlet in communication with a vacuum reservoir via the second check valve, the second check valve limiting from the second entraining inlet to the vacuum reservoir. 
         [0008]    One advantage of the above examples is that excess compressor pressure and flow is used to generate vacuum. In this way, downsized engines including a turbocharger or supercharger may generate vacuum, even during cold start. Further, an example throttle including a first inlet and a second inlet may control flow through an example aspirator, as well as flow to an example manifold not from the aspirator, simplifying an intake system configuration. In examples including a plurality of aspirators one of the plurality may be configured for high flow and another may be configured for low flow, increasing an intake system&#39;s efficiency at generating vacuum over a wide pressure range. 
         [0009]    It will be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description, which follows. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined by the claims that follow the detailed description. Further, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  shows a first example intake system for an engine. 
           [0011]      FIG. 2  shows a first example aspirator. 
           [0012]      FIG. 3  shows a second example aspirator. 
           [0013]      FIGS. 4-7  show further example intake systems for an engine. 
           [0014]      FIGS. 8 and 9  show a first example passive control valve. 
           [0015]      FIG. 10  shows a sixth example intake system for an engine. 
           [0016]      FIGS. 11 and 12  show a first example throttle included in an intake system, and in communication with an aspirator. 
           [0017]      FIGS. 13-18  show example multi-aspirator intake systems. 
           [0018]      FIG. 19  shows a first example of an intake system including an aspirator integrated with additional engine systems. 
           [0019]      FIG. 20  shows a second example of an intake system including an aspirator integrated with additional engine systems. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    A first example intake system for an engine is described, with respect to  FIG. 1 , to introduce possible devices, arrangements and configurations of an intake system including an aspirator. Example aspirators are discussed in more detail with respect to  FIGS. 2 and 3 . Additional example intake systems are described with respect to  FIGS. 4-7  and  10 .  FIGS. 8 and 9  show an example passive control valve included in some example intake systems. An example throttle included in example intake systems is discussed with respect to  FIG. 10-12 . Finally, multi-aspirator intake systems are described with respect to  FIGS. 13-18 . Integration of example intake systems with additional engine systems, such as fuel vapor purge and positive crankcase ventilation systems, is discussed with respect to  FIGS. 19 and 20 . 
         [0021]      FIG. 1  shows a first example intake system  10  for an engine  12 . In the present example, engine  12  is a spark-ignition engine of a vehicle, the engine including a plurality of cylinders  14 , each cylinder including a piston. Combustion events in each cylinder  14  drive the pistons which in turn rotate crankshaft  16 , as is well known to those of skill in the art. Further, engine  12  may include a plurality of engine valves, the valves coupled to the cylinders  14  and controlling the intake and exhaust of gases in the plurality of cylinders  14 . 
         [0022]    In the present example, intake system  10  includes an intake passage  18  and an aspirator  20 . The intake passage  18  includes throttle  22  and an intake manifold  24 . Manifold  24  provides air to engine  12 . Air may enter intake passage  18  from an air intake system (AIS) including an air filter in communication with the vehicle&#39;s environment, for example. Further, throttle  22  is located intermediate to the intake manifold  24  and a compressor  25 , the throttle  22  limiting the air entering intake manifold  24 . 
         [0023]    In the present example, intake passage  18  also includes compressor  25  and intercooler  26 . Compressor  25  may be coupled to a turbine in an exhaust of engine  12 . Further compressor  25  may be, at least in part, driven by an electric motor or crankshaft  16 . Compressor  25  further includes a bypass passage  28  and compressor bypass valve (CBV)  30 . CBV  30  may be used to control a level of air pressure in a portion of intake passage  18  between compressor  25  and engine  12 , and in this way regulate a boost level, control for surge, etc. 
         [0024]    As briefly described above, intake system  10  includes aspirator  20 . Aspirator  20  may be an ejector, injector, eductor, venturi, jet pump, or similar passive device. Aspirator  20  has a motive flow entering inlet  32 . Motive inlet  32  communicates with the intake passage  18  intermediate the compressor  25  and the throttle  22  at a high pressure outlet  34  of the compressor  25 . In further examples, motive inlet  32  may communicate with additional high air pressure inputs. In the present example, and the aspirator having an entraining inlet  36  communicating with a vacuum reservoir  38  via a first check valve  40 . High pressure air at the motive inlet  32  may be converted to flow energy in the aspirator  20 , thereby creating a low pressure communicated to entraining inlet  36  and drawing air through entraining inlet  36 . The first check valve  40  allows vacuum reservoir  38  to retain any of its vacuum should the pressures in  36  and  38  equalize. Further, aspirator  20  includes an outlet  44 , in communication with the intake manifold. In the present example, the aspirator is the three port device including  32 ,  44 , and  36 . However, in further examples, check valves  40  and  42  are integrated into the device, and it will be appreciated that the device at  20  retains its name, “aspirator.” 
         [0025]    Further still, it should be appreciated that a flow path from  38  through  42  and continuing to  24  is designed carefully to not be flow restrictive. In this way vacuum may be recovered, should vacuum reservoir  38  ever be depleted. 
         [0026]    Additionally, vacuum reservoir  38  is always different from the intake manifold  24 . Vacuum reservoir  38  is a portion of, or device in, an engine system that utilizes vacuum. For example, vacuum reservoir  38  may be a vacuum cavity behind a diaphragm in a brake booster or a low pressure storage tank included in a fuel vapor purge system. 
         [0027]    In the present example, intake system  10  further includes an optional auxiliary check valve  42 . Auxiliary check valve  42  is in communication with the vacuum reservoir  38  and in communication with an outlet  44  of the aspirator. Further, the auxiliary check valve  42  limits flow from the outlet  11 , to the vacuum reservoir  38 . In this way, the auxiliary check valve  42  allows the vacuum reservoir  38  to retain its vacuum in the case where intake manifold  24  pressure rises above vacuum reservoir  38  pressure. Auxiliary check valve  42  limits communication from intake manifold  24  to vacuum reservoir  38 , as well. Auxiliary check valve  42  is shown integrated into the aspirator  20 , however in additional examples, auxiliary check valve  42  is separate from the aspirator  20 . 
         [0028]    Additionally, intake system  10  may include a control system  46  including a controller  48 , sensors  50  and actuators  52 . Example sensors include engine speed sensor  54 , engine coolant temperature sensor  56 , a mass air flow sensor  58 , and manifold air pressure sensor  60 . Example actuators include engine valves, CBV  30 , and throttle  22 . Controller  48  may further include a physical memory with instructions, programs and/or code for operating the engine. 
         [0029]    A plurality of arrows  62  illustrate example flowpaths by which intake air may pass through the intake system  10 . Air flows into intake passage  18  and reaches a low pressure compressor inlet  33 . Aspirator  20  communicates with intake passage  18  at  34 , and a passage at  34  may include profile or diameter which determines a rate at which air flows into the motive inlet  32 . In this way, a pressure difference between the compressor outlet  34  and the intake manifold  24  may be used to generate vacuum in the vacuum reservoir. Consequently, in downsized engines including a turbocharger or supercharger even during cold start, vacuum may be generated, regardless of an intake manifold pressure and without inclusion of a vacuum pump. For example, even when little manifold vacuum is present, sufficient vacuum may still be generated by harvesting the pressure difference compressor pressure and intake manifold pressure. 
         [0030]    Turning now to  FIG. 2 , a first example aspirator  200  is shown. Aspirator  200  is a venturi-type in the present example. In the present example, motive air is received at inlet  202 . Motive inlet  202  receives high pressure air, for example from a compressor outlet. Gas flowing out of aspirator  200  leaves via outlet  204  at a lower pressure, and continues, for example, to an intake manifold and/or a low pressure compressor inlet. A profile (e.g., a cross-sectional area) of the aspirator  200  tapers from the motive inlet  202  to an entraining inlet  206 , and then expands from the entraining inlet  206  to the outlet  204 . As a result, a high velocity, and a low pressure may be induced at the entraining inlet  206 , thus drawing air through the entraining inlet  206  from an example vacuum reservoir in communication with the aspirator, (e.g., via passage  208 ). A first check valve  210  limits reverse flow from the entraining opening to the vacuum reservoir. In this way, gases are removed from the vacuum reservoir but may be prevented from entering via the entraining inlet  206 . 
         [0031]    Further, aspirator  200  may include an auxiliary check valve  212  (shown in dashed lines to indicate its optional inclusion). In the present example, auxiliary check valve  212  limits flow from the outlet  204  to the example vacuum reservoir, the reservoir in communication with check valve  212  via passage  208 . In this way, when the outlet  204  has a low pressure, for example when it&#39;s in communication with an example intake manifold, auxiliary check valve  212  acts to increase vacuum in the example vacuum reservoir by facilitating the flow of gas to the outlet  204 . 
         [0032]    Further, the venturi-type aspirator  200 , may produce vacuum at  206  from flow going from  202  to  204  and from flow going from  204  to  206 . In some examples, aspirator symmetry allows for vacuum production in either flow direction. One advantage is that when the venturi is connected between an example intake manifold and an example intake passage a pressure difference between the intake manifold and intake passage pulls in air or vents air out, regardless of direction and produces vacuum in an example vacuum reservoir. 
         [0033]    Turning now to  FIG. 3 , a second example aspirator  300  is shown. Aspirator  300  is an ejector-type passive valve in the present example. In the present example, motive air flow is received at an inlet  302 . Motive inlet  302  receives high pressure air from, for example, a compressor outlet. Gas flowing out of aspirator  300  leaves via outlet  304  at a low pressure, and continues, for example, to an intake manifold and/or a low pressure compressor inlet. 
         [0034]    Aspirator  300  includes a motive nozzle,  312 . A profile (e.g., a cross-sectional area) of the motive inlet narrows along the length of the nozzle  312 , to a tip  314  of motive nozzle. As a result, a high velocity, and a low pressure may be induced at the nozzle tip  314 , thus drawing air through an entraining inlet  306  from an example vacuum reservoir in communication with the aspirator, (e.g., via passage  308 ). Further, the aspirator may include a profile that converges from the nozzle tip  314  and entraining inlet  306  to a throat  316  and then diverges from throat  316  to the outlet  304 . In one example, the throat  316  has a low pressure, and high velocity gas, further drawing air through the entraining inlet  306 . 
         [0035]    In the present example, aspirator  300  includes a first check valve  310  and auxiliary check valve  318 . However, both first check valve  310  and auxiliary check valve  318  are shown in dashed lines in  FIG. 3  to indicate their optional nature. In further examples of aspirator  300 , motive flow may come in through the inlet at  306  and entrained flow may come in passage  302 . Thus in the present example, the motive flow can either be on the inner core flow as shown explained above, or the motive flow can on the outer annular flow as is known to those of skill in the art. 
         [0036]    Turning now to  FIG. 4 , a second example intake system  410  for an example engine  412  is shown. Intake system  410 , includes example intake passage  418 , further including example compressor  425 , intercooler  426 , throttle  422 , and intake manifold  424 . Compressor  425  includes a high pressure outlet  434 , a bypass  428  and CBV  430 , and a low pressure inlet  433 , as described above with reference to  FIG. 1 . Additionally intake system  410  includes example control system  446 . 
         [0037]    Further, intake system  410  includes aspirator  420 , which itself includes example motive inlet  432 , entraining inlet  436 , outlet  444 , first check valve  440  and auxiliary check valve  442 . As described above, aspirator motive inlet  432  is in communication with intake passage  418  at compressor outlet  434 . Entraining inlet  436  is coupled to an example vacuum reservoir  438 . Further, outlet  444  is in communication with manifold  424 , as well as auxiliary check valve  442 . 
         [0038]    In the present example a solenoid valve  450  is included in intake system  410 . Solenoid valve may be a continuously variable valve, such as a butterfly valve. Solenoid valve  450  is coupled intermediate to the intake passage  418  and the motive inlet  432  of the aspirator  420 . Solenoid valve  450  may open and close in response to signals from controller  448  included in control system  446 . In a first mode, solenoid valve  450  may allow communication between intake passage  418  and aspirator  420  and in a second mode, solenoid valve may close and limit communication between intake passage  418  and aspirator  420 . In this way, solenoid valve  450  may ensure that a minimum vacuum threshold is maintained in manifold  424 . Further, the solenoid valve can be closed (partially or wholly) when the airflow is higher than desired and the intake manifold is already producing target vacuum levels. Solenoid valve  450  is one example of a valve that can control flow through aspirator  420  and also ensure that a minimum vacuum threshold is maintained in manifold  424  (further examples are discussed below). 
         [0039]    Turning now to  FIG. 5 , a third example intake system  510  for an example engine  512  is shown. Intake system  510  includes example intake passage  518 , further including example compressor  525 , intercooler  526 , throttle  522 , and intake manifold  524 . Compressor  525  includes a high pressure outlet  534 , a bypass  528  and CBV  530 , and a low pressure inlet  533 , as described above with reference to  FIG. 1 . Additionally intake system  510  includes example control system  546 . 
         [0040]    Further, intake system  510  includes aspirator  520 , which itself includes example motive inlet  532 , entraining inlet  536 , outlet  544 , first check valve  540  and auxiliary check valve  542 . As described above, aspirator motive inlet  532  is in communication with intake passage  518  adjacent compressor outlet  534 . Entraining inlet  536  is coupled to an example vacuum reservoir  538 . Further, outlet  544  is in communication with auxiliary check valve  542 . 
         [0041]    Additionally, in the present example, intake system  510  further includes a manifold check valve  550  intermediate the outlet  544  of the aspirator  520  and the manifold  524 . The manifold check valve  550  limits flow from the intake manifold  524  to the outlet  544 . Further, outlet  544  of the aspirator  520  is in communication with the intake passage of the compressor, adjacent low pressure compressor inlet  533 . Because low pressure compressor inlet  533  is the point at which compressor  525  receives air before that air travels further on in intake system  510 , inlet  533  is said to be upstream of compressor  525 . Intake system  510  further includes an intake check valve  552  intermediate to the outlet  544  of the aspirator  520  and the intake passage  518 . The intake check valve  552  limits flow from the intake passage to the outlet. In additional examples, intake system  510  may include only one of the manifold check valve  550  and intake check valve  552 . 
         [0042]    In the present example, the resistance of the check valves  550  and  552  may maintain a minimum vacuum threshold in manifold  524 . Further, the check valves may ensure that the outlet  544  is in communication with one of the intake passage  518  upstream of the compressor  525  or the manifold  524 , depending on which of these two locations has a lower pressure. The aspirator inlet  532  may be the highest pressure point in the system. In further examples, the placement of check valves  552  and  550  passively control pressure so that the aspirator outlet is the lowest pressure point in intake system  510 . Thus the aspirator may enjoy the benefit of using the greatest available air pressure difference to produce vacuum. 
         [0043]    Turning now to  FIG. 6 , a fourth example intake system  610  for an example engine  612  is shown. Intake system  610 , includes example intake passage  618 , further including example compressor  625 , intercooler  626 , throttle  622 , and intake manifold  624 . Compressor  625  includes a high pressure outlet  634 , a bypass  628  and CBV  630 , and a low pressure inlet  633 , as described above with reference to  FIG. 1 . Additionally intake system  610  includes example control system  646 . 
         [0044]    Further, intake system  610  includes aspirator  620 , which itself includes example motive inlet  632 , entraining inlet  636 , outlet  644 , and first check valve  640 . Entraining inlet  636  is coupled to an example vacuum reservoir  638 . As described above, aspirator motive inlet  632  is in communication with intake passage  618  at compressor outlet  634 . Further, outlet  644  is in communication with a low pressure compressor inlet  633 , upstream of compressor  625  in intake passage  618 . An auxiliary check valve limiting communication between outlet  644  and vacuum reservoir  638  is not shown included in intake system  610 . However, it will be understood that intake system  610  may further include such an example auxiliary check valve. 
         [0045]    Additionally, intake system  610  includes example manifold check valve  650  intermediate vacuum reservoir  638  and the manifold  624 . Manifold check valve  650  limits flow from the intake manifold  624  to the vacuum reservoir  638  in the present example. The resistance of manifold check valve  650  may maintain a minimum vacuum threshold in manifold  624  and/or in vacuum reservoir  638 . Further, by including manifold check valve  650  independent of aspirator  620  vacuum in vacuum reservoir  638  is maintained regardless of a pressure at either the compressor inlet  633  or outlet  634 . 
         [0046]    Turning now to  FIG. 7 , a fifth example intake system  710  for an example engine  712  is shown. Intake system  710 , includes example intake passage  718 , further including example compressor  725 , intercooler  726 , throttle  722 , and intake manifold  724 . Compressor  725  includes a high pressure outlet  734 , a bypass  728  and CBV  730 , and a low pressure inlet  733 , as described above with reference to  FIG. 1 . Additionally intake system  710  includes example control system  746 . 
         [0047]    Further, intake system  710  includes aspirator  720 , which itself includes example motive inlet  732 , entraining inlet  736 , outlet  744 , first check valve  740  and auxiliary check valve  742 . As described above, aspirator motive inlet  732  is in communication with intake passage  718  at compressor outlet  734 . Entraining inlet  736  is in communication with an example vacuum reservoir  738 . Further, outlet  744  is in communication with manifold  724 , as well as auxiliary check valve  742 . 
         [0048]    In the present example a passive control valve  750  is included in intake system  710 . Passive control valve  750  is intermediate the intake passage  718  and the motive inlet  732  of the aspirator  720 . Passive control  750  may be located anywhere along a flow conduit  721  between  734  and  724 . At high levels of intake manifold  724  vacuum, passive valve  750  can restrict or shut. In this case, the vacuum needed for vacuum reservoir  738  is provided mainly from intake manifold  724 . At low levels of intake manifold  724  vacuum, passive valve  750  can open resulting in copious flow through the ejector thus providing the vacuum required at vacuum reservoir  738 . 
         [0049]    Also, passive control valve  750  may increase or limit communication between intake passage  718  and aspirator  720  in response to a pressure difference between the intake passage  718  and aspirator  720 . Further, one example of passive control valve  750  (discussed below with respect to  FIGS. 8 and 9 ) may include a first operating mode having a first flow rate, and a second operating mode having a second flow rate, the first flow rate greater than the second. 
         [0050]    An example device having a similar flow characteristic to  750  is a Positive Crankcase Ventilation valve (PCV valve). When vacuum is high, valve  750  restricts flow. When vacuum is low, valve  750  un-restricts flow. Further, valve  750  has a third mode; when a threshold pressure is present at valve  750 , it may shut. In this way valve  750  may vary flow restriction based on pressure differential. In a PCV valve, this is called the backfire mode. In additional configurations where valve  750  lies between  724  and  744 , valve  750  may take on the function of valve  742 , making valve  742  optional. 
         [0051]    In additional examples, passive control valve  750  is positioned intermediate to the aspirator  720  and at least one of intake manifold  724  or low pressure compressor input  733 . Further, passive control valve  750  may ensure that a minimum vacuum threshold is maintained in manifold  724 , and may have analogous to a two port pressure regulator. Passive control valve  750  is one example of a valve that can control flow through aspirator  720  and also ensure that a minimum vacuum threshold is maintained in manifold  724 . 
         [0052]      FIG. 8  shows an example passive control valve  800  in a first position, the first position being a closed position. The closed position shown in  FIG. 8  is one example of a rest position. The rest position is one example of a backfire position where intake manifold pressure exceeds crankcase pressure and is the maximally flow restrictive position. Valve  800  includes a valve body  802  having a stem  804 . Stem  804  has a first profile  806  and a second profile  808 . Further, valve  800  includes a valve housing  810  that defines both a main opening  812 , a stem opening  814 , a first chamber  816 , and a second chamber  818 , the housing  810  sustainably containing valve body  802 . Valve housing further defines a second chamber  818 ; valve stem  804  penetrates through stem opening  814  into the second chamber  818 . Further, a valve head  822  included in valve body  802  is coupled to a spring  824 . 
         [0053]    In the present closed position a valve head  822  (included in valve body  802  and coupled to the stem  804 ) seals main opening  812  from first chamber  816 . Further, pressure in first chamber  816  may be greater than at opening  812 . In additional examples, spring  824  extends from valve head  816  to valve housing  810  adjacent stem opening  814 , and increases the force on valve head  822  against housing  810 . 
         [0054]      FIG. 9  shows the example passive control valve  800  in a second, open position. Spring  824  is during a compressed spring mode.  FIG. 9  is illustrative and a spacing between coils of spring  824  may be less than a spacing shown in  FIG. 8 . A force on valve head  822  from the pressure communicated via main opening  812  overcomes a force exerted on valve body  802  from spring  824  and second chamber  818 . An annular passage  820  between first chamber  816  and second chamber  818  is defined by one of the first profile  806  or the second profile  808  and stem opening  812 . Annular passage  820  includes a cross-sectional area that partially determines a rate of flow through the stem opening  812  and thus through valve  800 . 
         [0055]    The profile of the stem  804  defining annular passage  820  may change in response to the displacement of the valve body. In the present example, second profile  808  and stem opening  812  collectively define the annular passage  820  (e.g., the valve  800  controls for a second flow rate in a second operating mode). In the additional examples, first profile  806  and stem opening  812  collectively define the annular passage  820  (e.g., the valve  800  controls for a first flow rate in a first operating mode). As a pressure on valve head  814  increases, the force on spring  824  increases, changing the displacement of the valve body  802 . In this way a pressure difference between a second chamber and the first chamber may control flow through the valve  800 . Additional examples of valve  800  include additional profiles (e.g., a cone profile, or profile including a parabolic-shaped edge), to further control an example annular passage cross-sectional area in response to displacement of the valve body  802 . As illustrated, valve  800  depends on a gravitational orientation. Further examples do not have this orientation dependence. 
         [0056]    Turning now to  FIG. 10 , a sixth example intake system  1010  for an example engine  1012  is shown. Intake system  1010  includes example intake passage  1018 , further including example compressor  1025 , intercooler  1026 , and intake manifold  1024 . Optional compressor  1025  includes a high pressure outlet  1034 , a bypass  1028  and CBV  1030 , and a low pressure inlet  1033 , as described above with reference to  FIG. 1 . Additionally intake system  1010  includes example control system  1046 . 
         [0057]    Further, intake system  1010  includes aspirator  1020 , which itself includes example motive inlet  1032 , entraining inlet  1036 , outlet  1044 , and first check valve  1040 . As described above, aspirator motive inlet  1032  is in communication with intake passage  1018  at compressor outlet  1034 . However, in further examples of intake system  1010 , motive inlet  1032  may be in communication with intake passage  1018  at additional locations, such as at compressor inlet  1033  (as indicated by dashed line  1050 ). Entraining inlet  1036  is coupled to an example vacuum reservoir  1038 . Further, outlet  1044  is in communication with manifold  1024 . 
         [0058]    Further, intake system  1010  includes a throttle  1052  positioned in intake passage  1018 , the throttle  1052  including a first inlet  1054 , a second inlet  1056 , and a plate  1058 . Throttle  1052  is one example of a ported throttle. The plate  1058  is located intermediate the first inlet  1054  and an outlet  1060 , the second inlet  1056  located intermediate the throttle plate  1058  and the first inlet  1054 . The outlet  1044  of the aspirator  1020  is in communication with the second inlet  1056  of the throttle  1052 . When a throttle plate  1058  is rotated to a first angle, second inlet  1056  may be in fluid communication with outlet  1060 , while the throttle plate  1058  limits communication between the first inlet  1054  and the outlet  1060 . In this way, throttle  1052  may control flow through aspirator  1020 . Intake system  1010  includes example ported throttle  1052  so that flow through an example aspirator as well as flow to an example manifold not from the aspirator may be controlled by a single valve. In this way intake system  1010  has a simplifying configuration. Further, throttle  1052  is discussed in more detail below with respect to  FIGS. 10 and 11   
         [0059]    Further, intake system  1010  includes a second check valve  1042  (an example manifold check valve) coupled intermediate the vacuum reservoir  1038  and the manifold  1024 . The second check valve  1042  limits flow from the intake manifold  1024  to the vacuum reservoir  1038 . 
         [0060]    Turing now to  FIGS. 11 and 12 , an example ported throttle  1110  positioned in an example intake passage  1100 , the throttle  1110  including a first inlet  1112 , a second inlet  1114 , an outlet  1116 , and a plate  1118 . As described above with respect to  FIG. 10 , the plate  1118  is located intermediate the first inlet  1112  and outlet  1116 , the second inlet  1114  located intermediate the throttle plate  1118  and the first inlet  1112 . An example aspirator outlet is in communication with the second inlet  1114 . 
         [0061]      FIG. 11  shows throttle plate  1118  in a first, closed position. In the present example, throttle  1110  is a butterfly-type valve that may be rotated to control fluid communication of at least one of the first inlet  1112  and the second inlet  1114  with the outlet  1116 . During a warm idle air flow rate, the throttle is closed, as illustrated. In further examples the throttle plate  1118  may be near closed. In a closed or near closed position, the throttle plate  1118  limits communication between the second inlet  1114  and the outlet  1116 . In this way, throttle  1110  may reduce air flow through an example aspirator. Further, in the present example an example intake manifold may supply vacuum. 
         [0062]      FIG. 12  shows throttle plate  1118  in a second, substantially open position. When the throttle is substantially open (for example, during a cold start emission reduction (CSER) event) the throttle enables fluid communication between the second inlet  1114  and the outlet  1116 . In this way the throttle opens enough to expose second inlet  1114  to an example intake manifold vacuum, thus causing air flow through an example aspirator coupled to second inlet  1114 . 
         [0063]    Turning now to  FIG. 13 , shows a first example of an intake system  1310  having a plurality of aspirators. Multi-aspirator intake system  1310  includes at least first example aspirator  1314  and second example aspirator  1316  and may be included as part of an intake in an example vehicle to provide air for an example engine. First and second aspirators ( 1312  and  1314  respectively) may be example ejectors, injectors, eductors, venturi valves, jet pumps, or similar passive valve to generate vacuum (as discussed above, for example with respect to  FIGS. 2 and 3 . Further, first aspirator  1314  may be a different type of aspirator than second aspirator  1316 , and may have smaller or larger physical dimensions than second aspirator  1316 . In some examples, one of the first or second aspirator may be configured for high flow and the other of the two may be configured for low flow, thereby increasing an intake system&#39;s efficiency at generating vacuum over a wide pressure range. In this way, the aspirators  1314  and  1316  may be staged so that low pressure produced by one aspirator used by the other aspirator. By staging the aspirators in this way a deeper vacuum may be created than would otherwise be created with a single aspirator. 
         [0064]    First aspirator  1314  has a first motive inlet  1318 , first entraining inlet  1320 , and first outlet  1322 . The first motive inlet  1318  is in communication with an air pressure input  1334 . One example of air pressure input  1334  is a high pressure outlet of a compressor (as described above, with respect to  FIGS. 1 ,  4 - 7 , and  10 ). Additional examples of air pressure input  1334  include an intake passage, for example adjacent a low pressure compressor inlet. First aspirator may include first check valve  1324  and is shown in dashed lines to indicate its optional nature. First check valve  1324  is positioned intermediate first entraining inlet  1320  and an example vacuum reservoir  1342 . Furthermore, first check valve  1324  may limit communication from the first entraining inlet  1320  to vacuum reservoir  1342 . Additionally, first outlet  1322  is in communication with a low pressure output  1338 , examples of which include an intake manifold, and an intake passage (e.g., at a low pressure compressor input). 
         [0065]    Second aspirator  1314  has a second motive inlet  1326 , second entraining inlet  1328 , second outlet  1330 , and second check valve  1332 . In some examples, second motive inlet  1326  is in communication with input  1334 . In the present example, the second outlet  1330  is in communication with the first entraining inlet  1320 . In the present example entraining passage  1350  couples the second outlet  1330  and the first entraining inlet  1320 , and first check valve  1324  is coupled to the entraining passage  1350 . In further examples, the second motive inlet  1326  is in communication with the first outlet  1320  and the second outlet  1330  may be in communication with low pressure output  1338  (e.g., as described below with respect to  FIG. 18 ). Further, the second entraining inlet  1328  is in communication with vacuum reservoir  1342  via second check valve  1332 . The second check valve  1332  limits communication from the second entraining inlet  1328  to the vacuum reservoir  1342 . 
         [0066]    Additionally, a third check valve  1344  is positioned intermediate the first outlet  1322  and the vacuum reservoir  1342 . The third check valve  1344  limits flow from the vacuum reservoir  1342  to the first outlet  1322 . In further examples of intake system  1310  include additional examples a solenoid valve is positioned intermediate the input  1334  and at least one of the first motive inlet  1318  and the second motive inlet  1326 . 
         [0067]    Turning now to  FIG. 14 , a second example of an intake system  1410  having a plurality of aspirators is shown. Multi-aspirator intake system  1410  includes at least first aspirator  1414  and second aspirator  1416 . First aspirator  1414  may be a different type of aspirator than second aspirator  1416 , and may have smaller or larger physical dimensions than second aspirator  1416 . Further, first aspirator  1414  has a first motive inlet  1418 , first entraining inlet  1420 , and first outlet  1422 . The first motive inlet  1418  is in communication with an example air pressure input  1434 . Also, first aspirator may optionally include first check valve  1424  limiting communication from the first entraining inlet  1420  to vacuum reservoir  1442 . 
         [0068]    Additionally, first outlet  1422  is in communication with example intake manifold  1438  and intake passage  1440  (e.g., adjacent a low pressure compressor inlet). An outlet passage  1452  couples the first outlet  1422  to the intake manifold  1438 , the outlet passage  1452  coupling the first outlet  1422  to the intake passage  1440  as well. A manifold check valve  1446  is positioned in the outlet passage  1452  intermediate the first outlet  1422  and the intake manifold  1438 . The manifold check valve  1446  limits flow from the intake manifold  1438  to the first outlet  1422 . An intake check valve  1448  is positioned in the outlet passage intermediate the first outlet  1422  and the intake passage  1440 , the intake check valve limiting flow from the intake passage to the first outlet. 
         [0069]    Second aspirator  1416  has a second motive inlet  1426 , second entraining inlet  1428 , second outlet  1430 , and second check valve  1432 . In some examples, second motive inlet  1426  is in communication with input  1434 . In the present example, the second outlet  1430  is in communication with the first entraining inlet  1420  via an entraining passage  1450 . First check valve  1424  is coupled to the entraining passage  1450 . The second entraining inlet  1428  is in communication with vacuum reservoir  1442  via second check valve  1432  which limits communication from the second entraining inlet  1428  to the vacuum reservoir  1442 . Additionally, a third check valve  1444  is optionally positioned intermediate the first outlet  1422  and the vacuum reservoir  1442 . The third check valve  1444  limits flow from the vacuum reservoir  1442  to the first outlet  1422 . 
         [0070]      FIG. 15  shows a third example of an intake system  1510  having a plurality of aspirators. Multi-aspirator intake system  1510  includes at least first aspirator  1514  and second aspirator  1516 . Furthermore, intake system  1510  includes intake passage  1540 , which itself includes an example compressor  1560 , intercooler  1562  and throttle  1564 . 
         [0071]    First aspirator  1514  may be a different type of aspirator than second aspirator  1516 , and may have smaller or larger physical dimensions than second aspirator  1516 . Further, first aspirator  1514  has a first motive inlet  1518 , first entraining inlet  1520 , first outlet  1522 , and first check valve  1524 . The first motive inlet  1518  is in communication with a high pressure compressor outlet  1534 , which is a first air pressure input. First check valve  1524  limits communication from the first entraining inlet  1520  to vacuum reservoir  1542 . Additionally, first outlet  1522  is in communication with example intake manifold  1538 . Further examples of intake system  1510  include the first outlet  1522  in communication with intake passage  1540 , e.g., adjacent a low pressure compressor inlet. 
         [0072]    Second aspirator  1516  has a second motive inlet  1526 , second entraining inlet  1528 , second outlet  1530 , and second check valve  1532 . In the present example, motive inlet  1526  is in communication with intake passage  1548  adjacent low pressure compressor inlet  1536 . Further, an entraining passage  1550  couples the second outlet  1530  and the first entraining inlet  1520 , thereby placing them in fluid communication. First check valve  1524  is coupled to the entraining passage  1550 . Further, the second entraining inlet  1528  is in communication with vacuum reservoir  1542  via second check valve  1532  which limits communication from the second entraining inlet  1528  to the vacuum reservoir  1542 . Additionally, third check valve  1544  is positioned intermediate the first outlet  1522  and the vacuum reservoir  1542 . The third check valve  1544  limits flow from the vacuum reservoir  1542  to the first outlet  1522 . 
         [0073]      FIG. 16  shows a fourth example of an intake system  1610  having a plurality of aspirators. Multi-aspirator intake system  1610  includes at least first aspirator  1614  and second aspirator  1616 . First aspirator  1614  may be a different type of aspirator than second aspirator  1616 , and may have smaller or larger physical dimensions than second aspirator  1616 . Further, first aspirator  1614  has a first motive inlet  1618 , first entraining inlet  1620 , and first outlet  1622 . The first motive inlet  1618  is in communication with an example air pressure input  1634 , which includes a compressor outlet pressure (COP) and/or a throttle inlet pressure (TIP). Also, first aspirator may optionally include first check valve  1624  limiting communication from the first entraining inlet  1620  to vacuum reservoir  1642 . 
         [0074]    Additionally, first outlet  1622  is in communication with example intake passage  1640  (e.g., adjacent a low pressure compressor inlet). Intake passage  1640  includes a barometric pressure (BP). In additional examples an intake check valve  1648  is positioned intermediate the first outlet  1622  and the intake passage  1640  (for example adjacent a low pressure inlet) the intake check valve limiting flow from the intake passage to the first outlet. 
         [0075]    Second aspirator  1616  has a second motive inlet  1626 , second entraining inlet  1628 , second outlet  1630 , and second check valve  1632 . In some examples, second motive inlet  1626  is in communication with input  1634 . In the present example, the second outlet  1630  is in communication with the first entraining inlet  1620  via an entraining passage  1650 . The second entraining inlet  1628  is in communication with vacuum reservoir  1642  via second check valve  1632 . The second check valve  1632  limits communication from the second entraining inlet  1628  to the vacuum reservoir  1642 . 
         [0076]    In the present example a first check valve  1624  is positioned in the entraining passage  1650  intermediate the second outlet  1630  and the first entraining inlet  1620 . The first check valve  1624  limits flow from the first entraining inlet  1620  to the second outlet  1630 . Further, an outlet passage  1652  is coupled the entraining passage  1650  intermediate the second outlet  1630  and the first check valve  1624 . The outlet passage  1652  is also coupled to intake manifold  1638 , the manifold  1638  including an intake manifold pressure (MAP) and a manifold check valve  1648  limits flow from the intake manifold  1638  to the entraining passage  1650 . 
         [0077]    In the present example, a fuel vapor purge system  1660  is coupled to the entraining passage  1650  intermediate the second outlet  1630  and the outlet passage  1652 . Air passing through aspirator  1614  may draw air through entraining inlet  1620 . In this way, aspirator  1614  is may be used to assist in fuel vapor purge. In further examples of intake system  1610 , a PCV system is coupled to the entraining passage  1650  intermediate the second outlet  1630  and the outlet passage  1652 . 
         [0078]      FIG. 17  shows a fifth example intake system  1710  having a plurality of aspirators. Multi-aspirator intake system  1710  includes at least first aspirator  1714  and second aspirator  1716 . First aspirator  1714  may be a different type of aspirator than second aspirator  1716 , and may have smaller or larger physical dimensions than second aspirator  1716 . Further, first aspirator  1714  has a first motive inlet  1718 , first entraining inlet  1720 , and first outlet  1722 . The first motive inlet  1718  is in communication with an example air pressure input  1734 . Also, first aspirator may optionally include first check valve  1724  limiting communication from the first entraining inlet  1720  to vacuum reservoir  1742 . 
         [0079]    Additionally, first outlet  1722  is in communication with intake manifold  1738 . Throttle  1760  is one example of a ported throttle, discussed above (with respect to  FIG. 10 ). Throttle  1760  is positioned in intake passage  1740  and includes a first inlet  1762 , a second inlet  1764 , outlet  1766  and a plate  1768 . The outlet  1722  of the aspirator  1714  is in communication with the second inlet  1764  of the throttle  1760 . Throttle  1760  controls the pressure communicated to first outlet  1722 . In one example, when throttle plate  1768  is rotated to a first angle, second inlet  1764  may be in communication with outlet  1766 , while the throttle plate  1768  limits communication between the first inlet  1762  and the outlet  1766 . 
         [0080]    Second aspirator  1716  has a second motive inlet  1726 , second entraining inlet  1728 , second outlet  1730 , and second check valve  1732 . In the present example, the second outlet  1730  is in communication with the first entraining inlet  1720 . In the present example entraining passage  1750  couples the second outlet  1730  and the first entraining inlet  1720 , and first check valve  1724  is coupled to the entraining passage  1750 . In further examples, the second motive inlet  1726  is in communication with the first outlet and the second outlet  1730  may be in communication with intake passage  1740 , e.g., adjacent an example low pressure output. Further, the second entraining inlet  1728  is in communication with vacuum reservoir  1742  via second check valve  1732 . The second check valve  1732  limits communication from the second entraining inlet  1728  to the vacuum reservoir  1742 . 
         [0081]    Additionally, a third check valve  1744  is positioned intermediate the first outlet  1722  and the vacuum reservoir  1742 . The third check valve  1744  limits flow from the vacuum reservoir  1742  to the first outlet  1722 . 
         [0082]      FIG. 18  shows a sixth example intake system  1810  having a plurality of aspirators. Multi-aspirator intake system  1810  includes at least first aspirator  1814  and second aspirator  1816 . First aspirator  1814  may be a different type of aspirator than second aspirator  1816 , and may have smaller or larger physical dimensions than second aspirator  1816 . Further, first aspirator  1814  has a first motive inlet  1818 , first entraining inlet  1820 , and first outlet  1822 . The first motive inlet  1818  is in communication with a high pressure compressor outlet  1834 , which includes a COP and/or a TIP. Also, first aspirator includes first check valve  1824  limiting communication from the first entraining inlet  1820  to vacuum reservoir  1842 . 
         [0083]    Second aspirator  1816  has a second motive inlet  1826 , second entraining inlet  1828 , second outlet  1830 , and second check valve  1832 . In the present example, the first outlet  1822  is in communication with second motive inlet  1826 . First outlet  1822  and second motive inlet  1826  are in communication with intake passage  1840  adjacent an example low pressure inlet of a compressor and includes a BP. Further, the second entraining inlet  1828  is in communication with vacuum reservoir  1842  via second check valve  1832 . The second check valve  1832  limits communication from the second entraining inlet  1828  to the vacuum reservoir  1842 . Second outlet  1830  is in communication with an intake manifold  1838  which includes a MAP. A manifold check valve  1846  is positioned intermediate the second outlet  1830  and intake manifold  1838  to limit flow from the intake manifold  1838  to the second outlet  1830 . Additionally, a third check valve  1844  is intermediate the second outlet  1830  and vacuum reservoir  1842 , the third check valve  1844  limiting flow from the second outlet  1830  to the vacuum reservoir  1842 . 
         [0084]    In this configuration, any flow between BP to MAP through an aspirator contributes to actuator vacuum. Any flow from COP or TIP to BP contributes to actuator vacuum. Either of these flow paths may be controlled by solenoid valves, passive valves, or ported throttles. 
         [0085]    Turning now to  FIG. 19  a first example of an intake system  1910 , including an aspirator  1920  integrated with additional engine systems is shown. Intake system  1910  includes an example manifold  1924  in communication with an example engine  1912 . Intake system  1910  further includes example intake passage  1918  including throttle  1922 . Intake air, such as from an example AIS or intercooler comes from input  1926 . As discussed above, throttle  1922  may limit the air entering intake manifold  1924 . 
         [0086]    In the present example, fuel vapor purge system  1950  is in communication with manifold  1924  via fuel vapor purge valve  1952 . Further, PCV system  1954  is in communication with manifold  1924 . Intermediate PCV system  1954  and manifold  1924  is an example passive control valve  1956 , valve  1956  limiting communication from manifold  1924  to PCV system  1954 . 
         [0087]    PCV system  1954  is also in communication with aspirator  1920 . Aspirator  1920  includes example motive inlet  1932 , entraining inlet  1936 , outlet  1944 , first check valve  1940  and auxiliary check valve  1942 . Entraining inlet  1936  is in communication with an example vacuum reservoir  1938 . Further, outlet  1944  is in communication with manifold  1924 , as well as auxiliary check valve  1942 . 
         [0088]    In the present example, aspirator  1920  is positioned intermediate passive control valve  1956  and manifold  1924 . Crankcase gases vented to manifold  1924  pass through aspirator motive inlet  1932 , drawing air from entraining inlet  1936 , and leaving via outlet  1944 . In this way, air and crankcase gases may be used to generate vacuum during crankcase ventilation. 
         [0089]      FIG. 20  shows a second example intake system  2010  including an aspirator  2020  integrated with additional engine systems. Intake system  2010  includes an example manifold  2024  in communication with an example engine  2012 . Intake system  2010  further includes example intake passage  2018  including throttle  2022 . Intake air, such as from an example AIS or an example compressor and example intercooler comes from input  2026 . As discussed above, throttle  2022  may limit the air entering intake manifold  2024 . 
         [0090]    In the present example, fuel vapor purge system  2050  is in communication with manifold  2024  via fuel vapor purge valve  2052 . Further, PCV system  2054  is in communication with manifold  2024 . Intermediate PCV system  2054  and manifold  2024  is an example passive control valve  2056 , valve  2056  limiting communication from manifold  2024  to PCV system  2054 . 
         [0091]    Further, fuel vapor purge system  2050  is in communication with aspirator  2020 . Aspirator  2020  includes example motive inlet  2032 , entraining inlet  2036 , outlet  2044 , first check valve  2040  and auxiliary check valve  2042 . Entraining inlet  2036  is in communication with an example vacuum reservoir  2038 . Additionally, outlet  2044  is in communication with manifold  2024 , as well as auxiliary check valve  2042 . 
         [0092]    In the present example, aspirator  2020  is positioned intermediate fuel vapor purge valve  2052  and manifold  2024 . Purged fuel vapor, hydrocarbons and air vented to manifold  2024  pass through aspirator motive inlet  2032 , drawing air from entraining inlet  2036 , and leaving via outlet  2044 . In this way, fuel vapor and hydrocarbon gases may be used to generate vacuum during fuel vapor purge. In further examples, including additional flowpaths, passageways and/or check valves, vacuum can be generated from both PCV flow and purge flow. 
         [0093]    Finally, it will be understood that the articles, systems and methods described herein are exemplary in nature, and that these specific embodiments or examples are not to be considered in a limiting sense, because numerous variations are contemplated. Accordingly, the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and methods disclosed herein, as well as any and all equivalents thereof.