Multi-way emptying ejector system

Abstract

Multi-way emptying system (171) for a prime mover (112), comprising: an ejector (140) including a restriction (212), first and second inlets (142, 144), and an outlet (146) fixedly attached to an intake passage (118) of the engine (112); and at least one break point (203) at the constriction (212) or the inlets (142, 144), wherein the at least one break point (203) at the constriction (212) or the inlets (142, 144) includes a break point at the second inlet (144) and at the first inlet (142), wherein the thicknesses of the walls of the ejector (140) are reduced at the break points.

Description

BACKGROUND / SUMMARY

[0001] An ejector or venturi nozzle can be used as a vacuum source in two-way purge systems in an engine for fuel vapor recovery. For example, an ejector inlet may be coupled to an engine intake inlet via a hose or conduit upstream of a compressor, while an ejector outlet may be coupled to an engine intake inlet via a hose or other conduit downstream of the compressor. Fluid moving through the ejector provides vacuum at an ejector suction inlet, which may be coupled to a fuel vapor canister, to assist in purging the fuel vapor canister during boosted operation.

[0002] In some examples, the moving fluid may include fuel vapors, raw engine emissions, and / or engine crankcase vapors. If the ejector develops a leak, or if one or more hoses or lines coupled to the ejector deteriorate, it may be possible for the gases to escape to the atmosphere. The leaks may manifest, for example, at the ejector inlets or at the ejector outlet, e.g., when the ejector is stressed, causing a break or deterioration in the body of the ejector device. As another example, the leaks may manifest if the hoses, lines, or tubes coupled to the ejector inlets or outlet deteriorate, break, or decouple from the ejector.

[0003] DE 10 2011 104 217 A1 describes a switchable jet pump, for example, for a brake booster system with a vacuum brake booster. The jet pump has a transmission port as the first inlet for introducing a driving fluid into the jet pump, a suction port as the second inlet for suctioning a suction fluid into the jet pump, and a receiver port as the outlet for discharging driving fluid from the jet pump. The flow channel leading from the transmission port to the suction port narrows from the transmission port to a mixing area, and the resulting negative pressure draws suction fluid into the mixing area of ​​the flow channel. The jet pump has potential break points, with reinforcement struts provided in the area of ​​the transmission port to prevent breakage at potential break points.

[0004] Some approaches diagnose and detect leaks in ejector system components adjacent to and / or upstream of the ejector inlets. For example, using various sensors in an engine system, leaks can be detected in hoses, lines, or piping coupled to the ejector inlet or other locations in an ejector system upstream of the ejector outlet. However, such approaches fail to diagnose or detect leaks in an ejector system at or downstream of the ejector outlet. For example, a hose or other line can be used to couple the outlet of an ejector located upstream of a compressor to an engine intake inlet.If such a hose deteriorates or becomes disconnected from the ejector outlet, the resulting leak in the ejector system may go undetected, leading to increased emissions and degradation of engine operation.

[0005] The inventors herein have recognized the above-mentioned disadvantages and have developed a two-way purge system for a prime mover. According to one aspect of the invention, a multi-way purge system, such as a two-way system, for a prime mover comprises: an ejector having a restriction, a first and a second inlet, and an outlet fixedly attached to an intake manifold of the prime mover; and at least one break point at the restriction or inlets, including a break point at the second inlet and the first inlet, wherein the thicknesses of the ejector walls are reduced at the break points.According to another aspect of the invention, a multi-way purge system for an engine comprises: an ejector including a restriction, first and second inlets, an outlet, at least one break point at the restriction or inlets, and a check valve coupled to the outlet, wherein the outlet is fixedly attached to an intake passage of the engine, and wherein the break point includes a notched ring extending around an exterior of the ejector.

[0006] In this way, breakpoints in the ejector inlets or restriction can direct leaks away from the ejector outlet to the ejector inlets, where they can be detected without additional sensors or logic. Furthermore, a shutoff valve coupled to the ejector outlet can be closed in response to a detected leak to reduce unwanted emissions due to leaks in a pipe coupling the ejector outlet to the engine intake inlet. Furthermore, by coupling the ejector outlet directly to the intake line via a rigid connection, the stresses exerted on the ejector can cause the ejector to degrade along specified breakpoints adjacent to the inlets, allowing the leak to be detected and mitigating actions to be taken.Specifically, the approach can reduce the need to monitor all sections of an ejector to diagnose ejector leaks. Furthermore, the approach can reduce the number of sensors required to monitor an ejector for leaks. Even further, ejector leaks can be determined without adding any additional sensors to the vehicle system.

[0007] The above advantages and other advantages and features of the present description will be readily appreciated from the following detailed description, when taken alone or in conjunction with the accompanying drawings. It should be understood that the above summary is provided to introduce in simplified form a selection of the concepts further described in the following detailed description. It is not intended to identify key or essential features of the claimed subject matter, the scope of which is clearly defined by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that eliminate all of the disadvantages noted above or in any part of the disclosure. BRIEF DESCRIPTION OF THE CHARACTERS Fig. 1 and Fig. 2 show schematic diagrams of exemplary vehicle systems with two-way emptying ejector systems. Fig. 3 shows an exemplary ejector system according to the disclosure. Fig. 4 shows an example method for a two-way emptying system according to the disclosure. DETAILED DESCRIPTION

[0008] This description relates to diagnosing leaks in an ejector system included in a two-way purge system in a vehicle, such as the exemplary vehicle systems described in the Fig. 1 and Fig. 2. As described above, leaks, e.g., leaks due to stress on the ejector and / or deterioration in the ejector system components, such as the hoses or lines, can be diagnosed and detected in the system components at the inlets or upstream of the inlets in the ejector. As in the exemplary ejector or venturi nozzle system in Fig. 3, calibrated break lines or break points may be included throughout a body of the ejector to direct the leakage upstream of an outlet of the venturi nozzle so that the leaks can be detected. Furthermore, as shown in Fig. 3, the ejector outlet must be fixed directly to an intake manifold of the engine, so that the leaks in the ejector occur adjacent to the ejector inlets where they can be detected. As shown in Fig. As shown in Figure 4, such an ejector system may be used during boosted engine operation to vent fuel vapor from a canister into the engine intake manifold. Furthermore, leaks at locations in the ejector system upstream of the ejector outlet may be diagnosed, and mitigating actions may be performed in response to a detected leak.

[0009] The figures show Fig. 1 is a schematic representation of a vehicle system 100. The vehicle system 100 includes an engine system 102 coupled to a fuel vapor recovery system 200 and a fuel system 106. The engine system 102 may include an engine 112 having a plurality of cylinders 108. The engine 112 includes an engine intake inlet 23 and an engine outlet 25. The engine intake inlet 23 includes a throttle valve 114 fluidly coupled to the engine intake manifold 116 via an intake passage 118. An air cleaner 174 is positioned upstream of the throttle valve 114 in the intake passage 118. The engine outlet 25 includes an exhaust manifold 120 leading to an exhaust passage 122 that directs exhaust gas to the atmosphere. The engine exhaust 122 may include one or more emission control devices 124 that may be mounted in a closely coupled position within the exhaust.One or more emission control devices may include a three-way catalyst, a lean NOx trap, a diesel particulate filter, an oxidation catalyst, etc. It is recognized that other components may be included in the vehicle system, such as various valves and sensors, as further elaborated below.

[0010] The throttle valve 114 may be located in the intake passage 118 downstream of a compressor 126 of a boosting device, such as a turbocharger 50 or a supercharger. The compressor 126 of the turbocharger 50 may be disposed between the air cleaner 174 and the throttle valve 114 in the intake passage 118. The compressor 126 may be driven at least partially by the exhaust turbine 54, which is disposed in the exhaust passage 122 between the exhaust manifold 120 and the emission control device 124. The compressor 126 may be coupled to the exhaust turbine 54 via a shaft 56. The compressor 126 may be configured to draw in intake air at atmospheric pressure and boost it to a higher pressure. Boosted engine operation may be performed using the boosted intake air.

[0011] A level of boost may be controlled at least in part by controlling an amount of exhaust gas directed through the exhaust turbine 54. In one example, if a greater level of boost is requested, a greater amount of exhaust gas may be directed through the turbine. Alternatively, for example, if a lesser level of boost is requested, some or all of the exhaust gas may bypass the turbine via a turbine bypass passage under the control of a wastegate valve (not shown). An amount of boost may additionally or optionally be controlled by controlling an amount of intake air directed through the compressor 126. The controller 166 may adjust an amount of intake air pulled through the compressor 126 by adjusting the position of a compressor bypass valve (not shown).In one example, if a greater degree of boost is requested, a smaller amount of intake air may be directed through the compressor bypass passage.

[0012] The fuel system 106 may include a fuel tank 128 coupled to a fuel pump system 130. The fuel pump system 130 may include one or more pumps to pressurize the fuel delivered to the fuel injectors 132 of the engine 112. Although only a single fuel injector 132 is shown, additional fuel injectors may be provided for each cylinder. For example, the engine 112 may be a direct-injection gasoline engine, with additional injectors provided for each cylinder. It is understood that the fuel system 106 may be a returnless fuel system, a recirculation fuel system, or various other types of fuel systems. In some examples, a fuel pump may be configured to draw the tank's fluid from the bottom of the tank.The vapors generated in the fuel system 106 may be routed via a line 134 to a fuel vapor recovery system 200, described further below, before being exhausted to the engine intake inlet 23.

[0013] The fuel vapor recovery system 200 includes a fuel vapor containment device, illustrated here as a fuel vapor canister 104. The canister 104 may be filled with an adsorbent capable of capturing large amounts of vaporized HCs. In one example, the adsorbent used is activated carbon. The canister 104 may receive fuel vapors from the fuel tank 128 through conduit 134. Although the illustrated example shows a single canister, it should be understood that in alternative embodiments, multiple such canisters may be connected together. The canister 104 may communicate with the atmosphere through a vent 136. In some examples, a canister vent valve 172 may be located along the vent 136, coupled between the fuel vapor canister and the atmosphere, and may adjust a flow of air and vapors between the canister 104 and the atmosphere.However, in other examples, a canister vent valve may not be included. In one example, the operation of the canister vent valve 172 may be controlled by a canister vent solenoid (not shown). For example, based on whether the canister is to be emptied or not, the canister vent valve may be open or closed. In some examples, an evaporative leak detection module (ELCM) may be disposed in the vent opening 136, and may be configured to control venting and / or assist in leak detection.

[0014] Conduit 134 may optionally include a fuel tank isolation valve (not shown). Among other functions, the fuel tank isolation valve may allow a low pressure or negative pressure to be maintained in fuel vapor canister 104 without increasing the rate of fuel vaporization from the tank (which would otherwise occur if the fuel tank pressure were reduced). Fuel tank 128 may contain multiple fuel blends, including fuel with a range of alcohol concentrations, such as various gasoline-ethanol blends, including E10, E85, gasoline, etc., and combinations thereof.

[0015] The fuel vapor recovery system 200 may include a two-way purge system 171. The purge system 171 is coupled to the canister 104 via a conduit 150. The conduit 150 may include a canister purge valve (CPV) 158 disposed within the conduit. Specifically, the CPV 158 may control the flow of vapors along the conduit 150. The amount and rate of vapors vented by the CPV 158 may be determined by the duty cycle of an associated CPV solenoid 202. In one example, the duty cycle of the CPV solenoid may be determined by the controller 166 in response to engine operating conditions, including, for example, an air-fuel ratio. By causing the CPV to close, the control unit can seal the fuel vapor canister from the fuel vapor evacuation system so that no vapors are vented through the fuel vapor evacuation system.In contrast, by causing the CPV to open, the control unit can allow the fuel vapor evacuation system to evacuate the vapors from the fuel vapor canister.

[0016] The fuel vapor canister 104 operates to store vaporized hydrocarbons (HCs) from the fuel system 106. Under some operating conditions, such as during refueling, the fuel vapors present in the fuel tank may be displaced when liquid is added to the tank. The displaced air and / or vapors may be directed from the fuel tank 128 to the fuel vapor canister 104 and then through the vent 136 to the atmosphere. In this way, an increased amount of vaporized HCs may be stored in the fuel vapor canister 104. During later engine operation, the stored vapors may be vented back into the incoming air load via the fuel vapor purge system 200.

[0017] The conduit 150 is coupled to an ejector 140 in an ejector system 141 and includes a check valve 170 disposed therein between the ejector 140 and the CPV 158. The check valve 170 can prevent intake air from the ejector from flowing into the conduit 150, while allowing the flow of fluid and fuel vapors from the conduit 150 into the ejector 140.

[0018] A conduit 151 couples the conduit 150 to the intake inlet 23 at a position located within the conduit 150 between the check valve 170 and the CPV 158, at a position in the intake inlet 23 that is downstream of the throttle valve 114. For example, the conduit 151 may be used to route the fuel from the canister 104 to the intake inlet 23 during a purge event using the vacuum created in the intake manifold 116. The conduit 151 may include a check valve 153 disposed therein. The check valve 153 may prevent intake air from flowing from the intake manifold 116 into the conduit 150, while allowing fluid and fuel vapors to flow from the conduit 150 via the conduit 151 into the intake manifold 116 during a canister purge event.

[0019] Conduit 148 may be coupled to ejector 140 at a first port or inlet 142. Ejector 140 includes a second port 144 or inlet that couples ejector 104 to conduit 150. Ejector 140 is coupled to intake inlet 23 via a conduit 148 at a position upstream of throttle 114 and downstream of compressor 126. During a boost condition, conduit 148 may direct compressed air in intake conduit 118 downstream of compressor 126 into ejector 140 via port 142.

[0020] The ejector 140 may also be coupled to the intake conduit 118 at a position upstream of the compressor 126. In some examples, a conduit 152 may couple a third port 146, or outlet, of the ejector 140 to the intake conduit 118 at a position between the air filter 174 and the compressor 126. However, in other examples, as described in more detail below, the ejector 140 may be directly coupled to the intake conduit 118 at a position upstream of the compressor 126. For example, an outlet of the ejector may be fixedly attached directly to the intake passage 118, as described in more detail below.

[0021] The ejector 140 includes a housing 168 coupled to the ports 146, 144, and 142. In one example, only the three ports 146, 144, and 142 are included in the ejector 140. The ejector 140 may include various check valves disposed therein. For example, in some examples, the ejector 140 may include a check valve positioned adjacent each port in the ejector 140 such that unidirectional flow of fluid or air is present at each port. For example, the air from the intake line 118 downstream of the compressor 126 may B. be directed into the ejector 140 via the inlet port 142 and can flow through the ejector and leave the ejector at the outlet port 146 before being directed into the suction line 118 at a position upstream of the compressor 126.This flow of air through the ejector can create a negative pressure due to the Venturi effect at the inlet port 144, so that during the charging state, a negative pressure is provided across the port 144 of the conduit 150. In particular, a low-pressure region is created adjacent the inlet port 144, which can be used to draw purge vapors from the canister into the ejector 140.

[0022] In some examples, the ejector 140 may optionally include a shutoff valve 214 adjacent the outlet port 146, as described in more detail below. However, in other examples, a shutoff valve adjacent the outlet port 146 may not be included. For example, the shutoff valve 214 may be configured to close in response to certain conditions. For example, the shutoff valve may be configured to close and stop airflow through the ejector in response to degradation of one or more components of the fuel vapor recovery system, as described in more detail below.

[0023] The ejector 140 includes a nozzle 204 comprising a restriction that converges in a direction from the inlet 142 to the suction inlet 144, such that as air flows through the ejector 140 in a direction from the port 142 to the port 146, a negative pressure is created at the port 144 due to the Venturi effect. This negative pressure may be used to assist fuel vapor purge during certain conditions, such as during engine load conditions. In one example, the ejector 140 is a passive component. That is, the ejector 140 is designed to provide negative pressure to the fuel vapor purge system via line 150 to assist purge under various conditions without being actively controlled. While the CPV 158 and the throttle valve 114 may be controlled via the control unit 166, the ejector 140 may, for example,neither be controlled by control unit 166 nor be subject to any other active control. In another example, the variable geometry ejector may be actively controlled to adjust an amount of vacuum provided to the fuel vapor recovery system by the ejector via line 150.

[0024] During selected engine and / or vehicle operating conditions, such as after a light-off temperature of an emission control device has been reached (e.g., a threshold temperature has been reached after warming up from ambient temperature), and with the engine running, controller 166 may adjust the duty cycle of a canister vent valve solenoid (not shown) and open or hold open canister vent valve 172. Canister vent valve 172 may remain open, for example, except during vacuum tests performed on the system. At the same time, controller 12 may adjust the duty cycle of CPV solenoid 202 and open CPV 158. The pressures within the fuel vapor purge system 200 can then draw fresh air through the vent 136, the fuel vapor canister 104, and the CPV 158, causing the fuel vapors to flow into the line 150.

[0025] The operation of the ejector 140 within the fuel vapor purge system 200 during vacuum conditions will now be described. The vacuum conditions may include intake manifold vacuum conditions. For example, the intake manifold vacuum conditions may be present during an engine idle condition, where the manifold pressure is below atmospheric pressure by a threshold amount. This vacuum in the intake system 23 may draw fuel vapor from the canister through conduits 150 and 151 into the intake manifold 116. Further, at least a portion of the fuel vapors may flow from conduit 150 into the ejector 140 via port 144. Upon entering the ejector via port 144, the fuel vapors may flow through nozzle 204 to port 142. Specifically, the intake manifold vacuum causes fuel vapors to flow through restriction 212.Because the diameter of the area within the nozzle gradually increases in a direction from port 144 to port 142, the fuel vapors flowing through the nozzle in that direction diffuse, increasing the pressure of the fuel vapors. After passing through the nozzle, the fuel vapors exit the ejector 140 through the first port 142 and flow through conduit 148 to the intake port 118 and then to the intake manifold 116.

[0026] Next, the operation of the ejector 140 within the fuel vapor purge system 200 during the boost conditions will be described. The boost conditions may include conditions during which the compressor is operating. For example, the boost conditions may include a high engine load condition and / or a superatmospheric intake condition where intake manifold pressure is greater than atmospheric pressure by a threshold amount.

[0027] Fresh air enters intake passage 118 at air cleaner 174. During boost conditions, compressor 126 pressurizes the air in intake passage 118 so that the intake manifold pressure is positive. The pressure in intake passage 118 upstream of compressor 126 is lower than the intake manifold pressure during operation of compressor 126, and this pressure differential causes fluid to flow from intake conduit 118 through conduit 148 and through ejector inlet 142 into ejector 140. This fluid may, for example, contain a mixture of air and fuel. After the fluid has flowed into the ejector via the port 142, it flows through the converging opening 212 in the nozzle 204 in a direction from the port 142 to the outlet 146. Because the diameter of the nozzle gradually decreases in a direction of this flow, a low-pressure zone is created in a region of the opening 212 adjacent the suction inlet 144.The pressure in this low-pressure zone may be lower than the pressure in conduit 150. When this pressure differential exists, it provides a negative pressure across conduit 150 to draw fuel vapor from canister 104. This pressure differential may further cause fuel vapors from the fuel vapor canister to flow through the CPV and into port 144 of ejector 140. Upon entering the ejector, the fuel vapors, along with fluid from the intake manifold, may be drawn out of the ejector via outlet port 146 and into intake passage 118 at a position upstream of compressor 126. Operation of compressor 126 then draws the fluid and fuel vapors from ejector 140 into intake passage 118 and through the compressor.After the fluid and fuel vapors are compressed by the compressor 126, they flow through the charge air cooler 156 for delivery via the throttle valve 114 to the intake manifold 116.

[0028] The vehicle system 100 may further include a control system 160. The control system 160 is shown receiving information from a plurality of sensors 162 (various examples of which are described herein) and sending control signals to a plurality of actuators 164 (various examples of which are described herein). As one example, the sensors 162 may include an exhaust gas sensor 125 (located in the exhaust manifold 120) and various temperature and / or pressure sensors disposed in the intake system 23. For example, a pressure or airflow sensor 115 in the intake conduit 118 downstream of the throttle body 114, a pressure or airflow sensor 117 in the intake conduit 118 between the compressor 126 and the throttle body 114, and a pressure or airflow sensor 119 in the intake conduit 118 upstream of the compressor 126. Other sensors, such asAdditional pressure, temperature, air / fuel ratio, and composition sensors may be connected to various locations in the vehicle system 100. As another example, the actuators 164 may include fuel injectors 132, a throttle valve 114, a compressor 126, a fuel pump of the pumping system 130, etc. The control system 160 may include an electronic control unit 166. The control unit may receive input data from the various sensors, process the input data, and trigger the actuators in response to the processed input data based on a programmed instruction or code included in the processed input data.

[0029] As described above, leaks, e.g., leaks due to ejector or venturi loads and / or deterioration of ejector system components, such as hoses or lines, may be diagnosed and detected in system components at or upstream of the ejector inlets, such as inlets 144 and 142. For example, leaks may be detected at port 142 or in line 148 upstream of port 148, and leaks may be detected at port 144 or in line 150 upstream of port 144 using various sensors in the engine system. However, leaks or deterioration of the components of the ejector system 141 at positions at the outlet 146 or downstream of the outlet 146, e.g., within the line 152, cannot be detected. For example,If the outlet 146 deteriorates due to stress and leak detection is performed by the system, then no leak may be detected at the outlet 146. As another example, the system may not be able to detect that a leak is occurring if the line or hose 152 becomes disconnected from the outlet 146 or deteriorates.

[0030] Therefore, the ejector may include one or more calculated break lines or break points 203 throughout the body of the ejector 140 so that the leaks can be directed to occur adjacent to the inlets 142 and 144 where they can be detected by the system. As will be described below with reference to Fig. 3, the calculated break points may be the throat 212 and / or the ejector inlet 142 and / or the suction inlet 144. These calculated break lines may be configured to direct leaks away from the ejector outlet 146 to the ejector inlets 142 and 144. At the calculated break points, for example, the thickness of the ejector walls may be reduced such that, if the ejector experiences stress, the ejector degrades at one of the prescribed break points positioned adjacent to the ejector inlets, e.g., ports 144 and 142, where the leaks may be detected by a leak detection system. Further, in some examples, as described in more detail below, a shutoff valve 214 may be provided at the ejector outlet, e.g.,at the outlet 146, be configured to shut off flow through the converging orifice 212 into the intake line 118 upstream of the compressor 126 in response to a leak detected upstream of the converging orifice and the low pressure region of the ejector.

[0031] Fig. 2 shows another exemplary vehicle system 100 that includes an ejector system 141. In Fig. 2 numbers shown that correspond to the numbers in Fig. 1 same, correspond to the same in Fig. 1 and described above. Fig. 2 shows an exemplary ejector system including an ejector or venturi nozzle 140 coupled directly to the engine intake manifold 118 in a position upstream of the compressor 126 without the use of any conduit or hose between the ejector outlet 146 and the intake manifold 118.

[0032] In Fig. 2, it is shown that an outlet 146 of the ejector 140 is coupled directly to the intake line 118 at a position upstream of the compressor 126, between the compressor 126 and the air filter 172. As with respect to Fig. 3 will be described in more detail below, the outlet 146 may be fixedly connected to the suction line 118, for example, upstream of the compressor 126. In this way, a hose or line, such as the one shown in Fig. 1, line 152, can be eliminated from the ejector system. Furthermore, due to the rigid coupling of the outlet 146 to the intake line 118, the stresses on the ejector 140 can cause leaks to occur at one or more of the fracture lines 203 adjacent to the ejector inlets 142 and 144, where leaks can be detected. As shown in Fig. 2, in some examples, a shutoff valve 214 may optionally be provided adjacent the outlet 146 to shut off flow if a leak is detected in the ejector system. However, in other examples, the shutoff valve 214 may be omitted, or it may be positioned at other locations within the ejector 140. For example, a shutoff valve may be included adjacent the inlets 142 and / or 144.

[0033] Fig. Figure 3 shows an example ejector or Venturi nozzle coupled to the intake line 118 upstream of the compressor 126 and containing the calculated fracture lines or fracture points in the walls 302 of the ejector body 168. The calculated fracture points are predetermined areas of the ejector where fractures are expected to occur preferentially due to stresses on the ejector body. Fig. 3 numbers shown, the numbers from the Fig. 1 and Fig. 2 same, correspond to the same in the Fig. 1 and Fig. 2 and described above. The ejector 140 includes a nozzle 204 forming a constriction or throttle that converges in a direction from the flow inlet 142 to the outlet 146. In particular, a distance 329 between the inner walls 330 of the nozzle 204 decreases in a direction from the flow inlet 142 to the flow outlet 146 along a central axis 306.

[0034] Fig. 3 shows that a flow outlet 146 of the ejector 140 is disposed directly in a position in the intake line 118 that is upstream of the compressor 126 in the intake line 118. For example, the walls 302 of the ejector may be rigidly attached to the walls 304 of the intake line 118 so that the flow outlet of the ejector is directly coupled to the intake line 118 without the use of any pipes, hoses, or other conduits positioned between the ejector body and the intake line. For example, the walls 302 of the ejector 140 may be welded to the walls 304 of the intake line 118, or they may be rigidly coupled in any suitable manner such that the stresses on the ejector body cause one or more of the fracture lines or fracture points to deteriorate.

[0035] The ejector 140 may be coupled to the intake conduit 118 in any suitable manner and at any suitable angle. A central axis 306 of the ejector 140, extending from the first inlet 142 to the outlet 146, may be substantially perpendicular to a direction of flow of gases in the intake conduit 118. However, in other examples, the axis 306 may form an angle with the direction of flow of gases in the intake conduit 118. Further, the ejector 140 may be coupled to the intake conduit 118 at any position of the ejector 204 adjacent to the converging nozzle. For example, the ejector 140 may be coupled to the intake conduit 118 at a position adjacent to the low-pressure region 308 near the suction inlet 144. Further, in some examples, at least a portion of the ejector 140 at the junction 310 between the ejector 140 and the intake conduit 118 may extend into the interior of the intake conduit 118.In other examples, however, the ejector 140 may not extend into the interior of the intake conduit at the junction 310. For example, the walls 302 of the ejector may be integrally formed with the walls 304 of the intake conduit 118 at the junction 310. Further, in some examples, as described above, a check valve may be disposed adjacent the outlet 146 of the ejector 140 and / or at other locations within the ejector. Although. Fig. 3 shows that the ejector 140 is directly coupled to the intake line 118, in other examples, such as in Fig. 1 and described above, the outlet 146 may be coupled to the intake line 118 via a hose or conduit, such as the hose 152, which extends from the ejector 140 to the intake line 118.

[0036] The ejector 140 may include one or more calculated fracture lines or fracture points at one or more locations along the body 168 of the ejector 140. Examples of the fracture lines are shown in Fig. 3 at 312, 314, 316 and 318. It should be obvious that the Fig. 3 are exemplary in nature and may be positioned at different locations along the ejector. Furthermore, in some examples, the ejector may include only one fracture line, e.g., one of fracture lines 312, 314, 316, or 318. However, in other examples, the ejector may include two or more fracture lines, e.g., two or more of fracture lines 312, 314, 316, and 318.

[0037] At the fracture lines, the thickness of the ejector wall may be reduced so that a fracture occurs at the fracture line when the ejector body experiences stress or otherwise deteriorates. For example, a rivet or a notch may be formed in the ejector wall at a fracture point. Further, in some examples, a fracture line may extend around an outer perimeter of the ejector body into the walls of the ejector at the fracture point. The fracture points may be stress increasers positioned in predetermined areas of the ejector body. For example, a fracture point may comprise a notched stress increaser link or a notched ring extending around the exterior of the ejector at one or more predetermined locations. The ejector need not include fracture points at or adjacent to the drive outlet 146.In particular, no break points need be included in a region of the ejector downstream of the suction inlet 144, between the suction inlet 144 and the intake conduit 118. However, one or more break points may be included at the suction inlet 144 and upstream of the suction inlet 144, e.g., at or in the constriction 212 and at the flow inlet 142, in the flow inlet 142, or adjacent to the flow inlet 142.

[0038] For example, the ejector 140 may include a fracture line 312 that runs around the circumference of the suction inlet 144. In some examples, the fracture line 312 may be substantially perpendicular to a central axis 320 of the suction inlet 144. In other examples, the fracture line 312 may form an angle with the central axis 320 of the suction inlet 144. As another example, the ejector 140 may include a fracture line 314 that runs around the circumference of the first inlet 142. The fracture line 314 may, for example, be positioned upstream of the nozzle 204. In some examples, the fracture line 314 may be substantially perpendicular to the central axis 306 of the ejector 140. However, in other examples, the fracture line 314 may form an angle with the central axis 320 of the suction inlet 144. As yet another example, the ejector 140 may include a fracture line 316 that runs around the circumference of the walls of the ejector in a position about the nozzle 204.This fracture line may be substantially perpendicular to the central axis 306 of the ejector 140. However, in other examples, a fracture line 318 may be formed around a circumference of the ejector around the nozzle 318 and form an angle with the central axis 306.

[0039] Fig. 4 shows an example method 400 for a two-way emptying system, such as a two-way emptying system 171 used in the Fig. 1 and Fig. 2. In method 400, an ejector system, such as ejector system 141, may be used during boosted engine operation to purge fuel vapor from a canister into the engine intake manifold. Further, leaks may be diagnosed at locations in the ejector system upstream of the ejector outlet, and mitigating actions may be performed in response to a detected leak.

[0040] At 402, method 400 includes determining whether a purge request has occurred. For example, a fuel vapor purge event may be initiated in response to an amount of fuel vapor stored in the fuel vapor canister being greater than a threshold amount. Further, purging may be initiated when a light-off temperature of an emission control device has been reached. If a purge request has occurred, then a purge event may be initiated, where controller 12 may adjust the duty cycle of CPV solenoid 202 and open CPV 158. Pressures within fuel vapor purge system 200 may then draw fresh air through vent 136, fuel vapor canister 104, and CPV 158, causing fuel vapors to flow into conduit 150.

[0041] In response to purge initiation at 402, method 400 proceeds to 404. At 404, method 400 includes determining whether boosted engine operation is occurring. Boosting conditions may include conditions where the compressor is operating. Boosting conditions may include, for example, a high engine load condition and / or a superatmospheric intake condition where intake manifold pressure is greater than atmospheric pressure by a threshold amount.

[0042] If at 404 the engine is not operating with boost, then vacuum conditions may be present, and method 400 proceeds to 408. The vacuum conditions may include intake manifold vacuum conditions. For example, intake manifold vacuum conditions may be present during an engine idle condition where the manifold pressure is below atmospheric pressure by a threshold amount.

[0043] At 408, method 400 includes supplying fuel vapor to the intake line downstream of the compressor. For example, the vacuum in intake system 23 may draw fuel vapor from the canister through lines 150 and 151 into intake manifold 116.

[0044] However, if the operating conditions of the boosted engine are present at 404, then method 400 proceeds to 410. At 410, method 400 includes routing air through the ejector. For example, fresh air may be routed past the air cleaner 174 into the intake passage 118. During boost conditions, the compressor 126 pressurizes the air in the intake passage 118 such that the intake manifold pressure is positive. The pressure in the intake passage 118 upstream of the compressor 126 is lower than the intake manifold pressure during operation of the compressor 126, and this pressure differential causes fluid to flow from the intake conduit 118 through the conduit 148 and through the ejector inlet 142 into the ejector 140. This fluid may include, for example, a mixture of air and fuel.After the fluid has flowed into the ejector via the port 142, it flows through the converging throat 212 in the nozzle 204 in the direction from the port 142 to the outlet 146.

[0045] At 412, method 400 includes drawing fuel vapor from the canister into the ejector. Because the diameter of the nozzle gradually decreases in a direction of this flow, for example, a low-pressure zone is created in an area adjacent to the restriction 212 of the suction inlet 144. The pressure in this low-pressure zone is lower than a pressure in the conduit 150. When this pressure differential exists, it provides a negative pressure to the conduit 150 to draw fuel vapor from the canister 104. This pressure differential may also cause a flow of fuel vapors from the fuel vapor canister through the CPV and into the port 144 of the ejector 140.

[0046] At 414, method 400 includes supplying fuel vapor to the intake passage upstream of the compressor. Upon entering the ejector, the fuel vapors may be drawn, for example, along with fluid from the intake manifold via the outlet port 146 from the ejector at a position upstream of the compressor 126 into the intake passage 118. Operation of the compressor 126 then draws the fluid and fuel vapors from the ejector 140 into the intake passage 118 and through the compressor. After being compressed by the compressor 126, the fluid and fuel vapors flow through the charge air cooler 156 for delivery to the intake manifold 116 via the throttle valve 114.

[0047] At 416, method 400 includes determining whether entry conditions for leak testing are met. For example, method 400 may decide to perform a diagnostic leak test after a threshold period between leak tests has been exceeded. In another example, a diagnostic leak test of the ejector system may be performed if the vacuum is not being generated by the ejector system at a desired rate.

[0048] If the entry conditions for testing for leaks are met at 416, method 400 proceeds to 418. At 418, method 400 includes diagnosing a leak upstream of the ejector orifice. In one example, the compressor is operated at a constant speed while the throttle position is constant and when the engine speed is constant. If less than a target pressure is developed downstream of the compressor, it may be determined that there is a leak upstream of the ejector orifice. For example, in some examples, the two conditions including the pressure downstream of the compressor being less than a threshold and the vacuum being provided by the ejector system at less than a threshold rate may also be the conditions for determining the leak of a component upstream of the ejector orifice.

[0049] At 420, method 400 includes diagnosing leaks upstream of a low-pressure region of the ejector. In one example, a valve is opened to initiate a flow of a moving fluid through the ejector. The moving fluid may be air, where the air may be compressed via a turbocharger. All vacuum consumers may be caused to be in a closed state, and the pressure within the components upstream of the low-pressure region of the ejector may be sensed by one or more pressure sensors. Air is drawn to the ejector from the components upstream of the low-pressure region of the ejector, assuming a limited leak exists. The moving fluid is returned to the engine with the air from the components upstream of the low-pressure region of the ejector at a location upstream of the compressor.If less than a threshold amount of negative pressure is developed in the components upstream of the low pressure region of the ejector, it can be determined that there is a leak in one or more components upstream of the low pressure region of the ejector.

[0050] At 422, method 400 includes determining whether a leak is detected. For example, as described above, leaks from the ejector may be diagnosed or detected located upstream of the converging orifice and the low-pressure region of the ejector. Furthermore, because fracture lines are included in the ejector body, as described above, leaks are directed from the ejector outlet to a location upstream of the converging orifice and the low-pressure region of the ejector.

[0051] If a leak is detected at 422, method 400 proceeds to 424. At 424, method 400 may optionally include closing a shutoff valve, if present, to interrupt flow through the ejector. For example, if a leak is detected at ejector inlets 142 and 144 or upstream of ejector inlets 142 and 144, then a shutoff valve, such as shutoff valve 214, may be adjusted to interrupt flow through the ejector's converging orifice and into the engine intake passage upstream of the compressor.

[0052] At 426, method 400 includes indicating deterioration. For example, if a leak is determined at 418 or 420, method 400 may provide the driver with an indication to have the engine serviced. Further, method 400 may store the leak information in memory and set a diagnostic code to alert an operator to take mitigating actions. For example, a no purge flow signal may be sent to the electronic control module (ECM) with a deterioration code.

Claims

[1] Multi-way emptying system (171) for a prime mover (112), comprising: an ejector (140) including a restriction (212), first and second inlets (142, 144), and an outlet (146) fixedly attached to an intake passage (118) of the engine (112); and at least one break point (203) at the constriction (212) or the inlets (142, 144), wherein the at least one break point (203) at the constriction (212) or the inlets (142, 144) includes a break point at the second inlet (144) and at the first inlet (142), wherein the thicknesses of the walls of the ejector (140) are reduced at the break points. [2] The system of claim 1, further comprising a shut-off valve (214) coupled to the outlet (146). [3] The system of claim 2, wherein the shutoff valve (214) is configured to close in response to a leak detected upstream of the outlet (146). [4] The system of claim 1, wherein the constriction (212) converges from the first inlet (142) to the second inlet (144). [5] The system of claim 1, wherein the first inlet (142) is coupled to the intake passage (118) between a throttle valve (114) and a compressor (126) of the engine (112) and the second inlet (144) is coupled to a fuel vapor canister (104). [6] The system of claim 5, wherein the second inlet (144) is coupled to the fuel vapor canister (104) via a conduit (150), the conduit (150) including a canister purge valve (158) disposed therein, and the conduit is coupled to the intake passage (118) downstream of the throttle valve (114) at a location in the conduit between the canister purge valve (158) and the second inlet (144). [7] The system of claim 1, wherein the at least one break point (203) at the restriction (212) or the inlets (142, 144) includes a break point at the second inlet (144) and the first inlet (142), wherein at the break points (203) the thicknesses of the walls of the ejector (140) are reduced via notched rings extending around an exterior of the ejector (140). [8] The system of claim 1, wherein the at least one break point at the constriction (212) or the inlets (142, 144) includes a break point at the second inlet (144) and the constriction (212), wherein the thicknesses of the walls of the ejector (140) are reduced at the break points, and wherein the break point at the constriction (212) is angled with respect to a central axis of the ejector (140) extending from the first inlet (142) to the outlet (146). [9] The system of claim 1, wherein the at least one break point (203) is configured to direct the leaks away from the outlet (146) to the inlets (142, 144) of the ejector (140), wherein there are no break points at the outlet (146) of the ejector (140). [10] The system of claim 1, wherein the at least one break point at the throat (212) or the inlets (142, 144) includes a break point at the throat (212), at the break point the thicknesses of the walls of the ejector (140) are reduced, and wherein the break point at the throat (212) is angled with respect to a central axis of the ejector (140) extending from the first inlet (142) to the outlet (146). [11] Multi-way emptying system (171) for a prime mover (112), comprising: an ejector (140) including a constriction (212), first and second inlets (142, 144), and an outlet (146); at least one break point (203) at the constriction (212) or the inlets (142, 144), but not at the outlet (146); and a shut-off valve (214) coupled to the outlet (146), the outlet (146) being fixedly attached to an intake passage (118) of the engine (112), and the break point (203) including a notched ring extending around an exterior of the ejector (140). [12] The system of claim 11, wherein the restriction (212) converges from the first inlet (142) to the second inlet (142), and wherein the restriction (212) extends at least partially into an intake passage (118) of the engine (112). [13] The system of claim 11, wherein the shutoff valve (214) is configured to close in response to a leak detected upstream of the outlet (146). [14] The system of claim 11, wherein the first inlet (142) is coupled to the intake passage (118) between a throttle valve (114) and a compressor (126) of the engine (112) and the second inlet (144) is coupled to a fuel vapor canister (104). [15] The system of claim 14, wherein the second inlet (144) is coupled to the fuel vapor canister (104) via a conduit (150), the conduit (150) including a canister purge valve (158) disposed therein, and the conduit (150) is coupled to the intake passage (118) downstream of the throttle valve (114) at a location in the conduit (150) between the canister purge valve (158) and the second inlet (144). [16] A method for a vehicle, the method comprising: in response to a drain request during a charging condition: Directing air from an engine intake inlet downstream of a compressor (126) through a converging restriction (212) in an ejector (140) into an engine intake inlet upstream of the compressor (126), wherein an outlet of the restriction is fixedly connected to the engine intake inlet upstream of the compressor (126), and wherein the ejector (140) includes a notched load increasing connection; Drawing a quantity of fuel vapor from a fuel vapor canister (104) over a low pressure region of the ejector (140); and Supplying the quantity of fuel vapor to the engine intake inlet upstream of the compressor (126) via the outlet fixedly attached to the engine intake inlet upstream of the compressor (126); and Diagnosing leaks from the ejector (140) located upstream of the converging throat (212) and the low pressure region of the ejector (140). [17] The method of claim 16, further comprising shutting off flow through the converging restriction (212) in the ejector (140) and into an engine intake inlet upstream of the compressor (126) in response to a leak detected upstream of the converging restriction (212) and the low pressure region of the ejector (140). [18] The method of claim 16, further including indicating degradation of the ejector (140) in response to a leak detected upstream of the converging throat (212) and the low pressure region of the ejector (140).

Images