DE60033057T2 - INTEGRATED AIR FUEL MODULE WITH LOW FUEL GAS EMISSIONS - Google Patents

Description

TECHNICAL TERRITORY

The The invention relates to a control of engine evaporative emissions of hydrocarbons and an integrated air / fuel module for a low Emission that is able to absorb such emissions.

BACKGROUND THE INVENTION

Carmakers have great Efforts are made to reduce emissions from the vehicles they create, diminish. Many emission sources were tracked. The two major sources of emissions are exhaust emissions (or "exhaust emissions") and hydrocarbons or hydrocarbons unburned fuel coming from other places on the vehicle vaporize (or "evaporative emissions"). In today's vehicles Fuel tanks are vented through coal tanks, leaving hydrocarbons from the escaping from the tank due to pressure differences Air are removed. This evaporation emission is stored, until it can be sucked into the engine and consumed. These Type of system is very effective to evaporative emissions to prevent it from escaping from the fuel tank system.

It There are sources other than the fuel tank that contribute to the hydrocarbon vapor emissions Vehicle can contribute. One such source is the "breathing" of the air intake system while the heat accumulation after stopping the engine and the daily temperature cycle. unburned Fuel, which turns off after stopping the engine in the intake system is vaporized in the air in the system. An air exchange between the air intake system and the environment carry these vaporized hydrocarbon emissions into the atmosphere. Activated carbon or "coal adsorber" have been used in Air cleaner housings installed to reduce these hydrocarbon emissions. Of the Carbon adsorber sucks the hydrocarbons and stops until the engine is started and the air flow over the Adsorber pulls the hydrocarbons back into the engine and the Adsorber rinsed.

A more usual Source of hydrocarbon emissions is a leak of Seals of both high pressure and low pressure fuel components and systems. Modern fuel supply systems include many such potential escape routes. These include O-rings, injector and Fuel Manifold Interfaces, Fuel Regulator Diaphragms, Terminations, Fuel Manifold Inlets, and outlets, Service valves and crankcase ventilation system interfaces and -Links. Each of these sites has the potential, emissions to escape into the surrounding environment.

A third usual The source of hydrocarbon emissions to the atmosphere is one Penetration of the fuel through the materials of the system. Hydrocarbons can most composites and elastomers that are commonly used be used in the automotive engine environment penetrate. Small amounts of hydrocarbons therefore escape through the Walls of composite components in the system and through the elastomer O-rings and seals the interfaces in the system. This leak is increased with higher fuel pressures that push the hydrocarbons out through the walls.

The above contributing sources are generally small in relation to the total evaporative emissions of the vehicle, and automakers can meet current standards without further development or control. However, to meet the requirements of zero or near zero evaporative emissions, engine suppliers and vehicle manufacturers will need to reduce the number of leaks and permeation points that can emit hydrocarbons. The US 5,740,779 discloses an evaporative emission reduction apparatus including a flapper valve configured to close the inlet port of a carburetor when the engine is off.

SUMMARY THE INVENTION

The present invention provides an integrated air / fuel module for an internal combustion engine according to claim 1, which reduces or eliminates the escape of hydrocarbon vapor emissions from the integrated air / fuel module system, subsystems, and components. In one embodiment, the integrated air / fuel module comprises a receiving means such as. A valve or a coal adsorber which blocks the escape of vaporized hydrocarbon emissions from the air intake of an internal combustion engine during engine off conditions. The module provides a reduced number of potential outer hydrocarbon escape and penetration routes to the surrounding atmosphere. Preferred geometries of the intake manifold in the module with the internal integration of other normally external systems such. B. fuel injection and crankcase ventilation systems accomplish the ingestion of fuel vapors occurring between engine operating periods, When the engine is off, inside or inside the air / fuel module.

These and further features and advantages of the invention will become apparent from the following Description of certain specific embodiments of the invention better understood together with the accompanying drawings.

SUMMARY THE DRAWINGS

In the drawings is:

1 a conceptual cross-sectional view of an integrated low fuel evaporation air / fuel module incorporating features according to the invention;

2 a cross-sectional view showing an exemplary shape of a receiving valve in the module inlet portion; and

3 a pictorial external view of a module for a V-8 engine with features of the invention.

DESCRIPTION THE PREFERRED EMBODIMENT

Referring first to 1 the drawings in detail, the reference numeral 10 in general, an exemplary low fuel vapor integrated air / fuel module for an internal combustion engine, the module comprising features according to the invention. The module 10 includes a housing 12 that internally has an air system 14 Are defined. The air system includes an inlet section in series 16 for charging charge air, a throttle control section 18 with a throttle 20 for controlling an air flow, a connecting portion 22 or intake pipe for adjusting the air flow, an intake air collector 24 for distributing and equalizing the air flow and a plurality of Ansaugkrümmmern 26 , The manifolds 26 are individually connected to the air collector and connect the air collector 24 with outlet channels 28 along a cylinder head interface 30 , coplanar with a mounting flange 32 of the housing 12 is. The manifolds 26 and outlet channels 28 distribute the airflow to intake ports of an engine, not shown, for intermittent passage to the associated cylinders during operation of the engine.

According to the invention, the inlet section comprises a receiving means for limiting the escape of fuel vapor from within the air system through the inlet section between periods of engine operation, ie when the engine is turned off. The air system 14 includes an exemplary embodiment of the receiving means in the form of a receiving valve 34 , which in more detail with the inlet section 16 in 2 is shown. The valve 34 comprises a pivotable edge-mounted flap valve element 36 with a sharp-edged sealing section 38 that with a valve seat 40 an air intake 42 in the inlet section 16 can be engaged when the valve is closed.

A feather 44 with variable force is engaged with the valve element to bias the valve in a closing direction. The feather 44 may be a curved spring steel strip, which may be shaped like a steel measuring tape, but is used as a spring. In the closed position shown in solid lines, the spring is positioned to exert maximum force around the valve member 36 firmly against the Ven tilsitz 40 to keep. When the valve is opened, the spring simply flattens out and bends to allow the valve to open against a lesser spring force.

An actuator 46 is for pivoting the valve element in the open position, in the 1 and 2 shown in dashed lines, provided. Any type of actuator that responds to signals indicating engine operating and stopping conditions may be used. The illustrated actuator represents a vacuum motor 46 which is the valve in response to a vacuum in the air system 14 , which indicates that the engine is in operation, opens. The vacuum motor 46 lets the valve through the spring 44 is closed and held in position when a vacuum near atmospheric pressure in the air system indicates that the engine is off.

The intake valve 34 and the vacuum motor 46 are merely exemplary of the many forms of suitable receiving means and actuators that could be used within the scope of the invention. Any electrical, pneumatic or hydraulic actuator could be used with appropriate controls as needed. Receiving means may include many forms of valves with pivotable blades, pistons, diaphragm valves and other check valves as examples. Coal adsorbers, instead of valves, can provide adequate containment of evaporative emissions and could be used as containment means within the scope of the invention.

According to the invention, the air / fuel module comprises 10 also a crankcase ventilation (PCV) system 50 that is primarily within the air system 14 of the housing 12 is included. The PCV system 50 includes a venting inflow passage 52 that cut the air inlet section between the intake valve 34 and the throttle 20 with a vent outlet 54 at the cylinder head interface 30 of the housing connects. Also a vent outflow channel 56 is provided, extending from the interface 30 to the air system 14 downstream of the throttle 20 extends. channels 52 . 56 are defined by walls that are primarily within the air system defined by the housing 14 of the module 10 are included. If the module 10 is installed on a motor, the channels become 52 . 56 with the outlet 54 connected to the crankcase chamber of the engine to guide bleed air through the crankcase. A PCV valve 58 is in the vent outflow channel 56 arranged to control the flow of air and crankcase vapors through the PCV system.

According to the invention, the air / fuel module comprises 10 a fuel injection system 60 that is primarily within the air system 14 of the housing 12 is included. The fuel injection system 60 includes one or more fuel rail (s) 62 extending longitudinally within the housing 12 extending / s. A variety of fuel injectors 64 , generally one for each engine cylinder, is connected to the fuel rail (s) to deliver fuel under pressure from a source external to the module housing 12 is fed, record. The fuel rail (s) 62 and the injectors 64 are completely inside the case 12 and the air system defined by the housing 14 attached. The injectors are positioned to deliver fuel through the exhaust passages 28 from the elbows 26 spray to mix it with air in the intake ports and cylinders of the associated engine (not shown). Preferably, the mounting positions of the injectors and all connections to the fuel rail and the fuel rail with incoming fuel lines in the Luftsys system 14 contain. Thus, any escape of evaporative emissions from the interior portions of the fuel system is retained within the air system and drawn into the engine during engine operation.

In addition to potential escape of evaporative emissions from interconnections between various elements of the fuel system, the PCV system, and backflow of gases from connected engine cylinders and intake ports, additional emissions may be introduced by permeation of fuel vapors and the like through molded plastic interior walls of the various systems in the housing 12 occur. Thus, it may be necessary to treat at least the outer walls of a plastic housing to maintain uptake of vaporized hydrocarbons and other materials within the housing when the engine is turned off. Alternatively, the housing 12 or at least its outer walls are made of cast aluminum or another metal with a low permeability.

In the embodiment of 1 is the housing 12 preferably from a plastic molded part in three sections, an inlet channel 66 , an upper manifold 68 and a lower manifold 70 , The lower manifold 70 includes the attachment interface 30 and the lower sections of the air collector 24 and the manifold 26 as well as the components of the fuel injection system 60 , The upper manifold 68 includes upper sections of the air collector 24 and the manifold 26 , The channels 52 . 56 of the PCV system extend into both header pipe sections 68 . 70 , the PCV valve 58 but is attached in the upper manifold. The entrance channel 66 is at the upper manifold 68 and can be removed to allow access for maintenance of the PCV valve.

With particular reference to 3 The drawings include the air / fuel module disclosed herein 72 further within a housing, 74 a coolant transition 76 with inner channels, not shown, for delivering a coolant between rows of cylinders of an associated V-8 engine. A liquid cooled electric alternator 78 is within the transition 76 attached and is cooled during engine operation by coolant in the channels. The figure also shows a laterally mounted electric throttle control 80 for the internal throttle. The housing 74 is made in two sections and includes an upper manifold 82 attached to a lower manifold 84 is attached. The latter includes a mounting flange 86 which is coplanar with the lower interface, not shown, attached to the associated engine cylinder heads. Inside are the elements of the module 72 essentially similar to those of the module 10 in 1 ,

When operating an engine with an air / fuel module 10 , as in 1 shown is the intake valve 34 opened at a start of the engine and remains open to the entry of charge air into the module air system 14 permit. Vaporized hydrocarbons and other vapors trapped in the air system are sucked into the engine with new air charges and burned in the engine. Any fuel vapors released during engine operation in the air system 14 are sucked into the engine in the same way and together with the through the PCV-Sys tem 50 purged crankcase vapors discharged from the engine crankcase by a vacuum in the module downstream of the throttle 20 be sucked off, burned. The throttle-controlled intake air, including any added crankcase vapors, flows through the header connection section or intake tube 22 and enters the inlet air collector 24 one. The air is then injected into the individual engine cylinders through the intake manifold 26 and outlet channels 28 of the module is sucked into associated intake ports of the engine. Fuel is then the incoming air through the fuel injectors 64 added that part of the fuel injection system 60 are that inside the air / fuel module 10 are included. The fuel is sprayed from the module directly into the cylinder head intake ducts, not shown, normally against the intake valve to aid in vaporization.

When the engine is stopped, the spring closes 44 the intake valve 34 and seals the inlet section 16 of the air system 14 from. Fuel and other vapors in the air system 14 or in the system 14 from the associated engine ducts or from the internal PCV and fuel injection systems 50 enter, thus become within the air system 14 trapped and prevented from escaping into the atmosphere. A restart of the engine sucks the stored vapors back into the engine and disposes of them by burning.

While the Invention with reference to certain preferred embodiments should be understood that many changes within the scope of the claims could be made. Accordingly, the Invention is not limited to the disclosed embodiments, but the full extent permitted by the language of the following claims Own circumference.

Claims (7)

Air / fuel module ( 10 ) for an internal combustion engine for receiving fuel vapor in an intake system of the engine between periods of engine operation, the module comprising: a housing ( 12 ) internally an air system ( 14 ) with an inlet section ( 16 ) and a plurality of intake manifolds ( 26 ) defined with the inlet section ( 16 ) and to outlet channels ( 28 ) adapted for connection to associated intake ports of the engine in which fuel is mixed with air from the air system; and characterized by receiving means in the inlet portion of the air system effective between periods of engine operation to limit the escape of fuel vapors entering or remaining in the air system after the engine is stopped by the inlet portion; wherein the receiving means comprises: a receiving valve ( 34 ), which is effective to the inlet section ( 16 ) of the air system to close when the engine is stopped and to open the inlet portion for an influx of air at a restart of the engine, a spring ( 44 ) with variable force, which with the intake valve ( 34 ) is engaged to the valve ( 34 ) in a closing direction, wherein the spring ( 44 ) exerts a greater force when the valve ( 34 ) is closed as if the valve ( 34 ) is open to maintain a safe closing of the valve against leakage of emissions. An air / fuel module according to claim 1, wherein the air system ( 14 ) a throttle control section ( 18 ) with a throttle valve ( 20 ), a connecting section ( 22 ) and an intake air collector ( 24 ), all in series between the inlet section ( 16 ) and the intake manifolds ( 26 ) are arranged connected. An air / fuel module according to claim 2, comprising: a PCV system ( 50 ), primarily in the air system ( 14 ) of the housing ( 12 ), wherein the PCV system includes a venting inflow channel ( 52 ), which connects the air system upstream of the throttle valve with a vent outlet adapted for connection to a crankcase chamber of an associated engine, and a vent outflow passage (14). 56 ) arranged to connect the crankcase chamber to the air system downstream of the throttle and a PCV valve ( 58 ) in the outflow channel ( 56 ) for controlling venting by the PCV system, wherein crankcase vapors within the PCV system exiting are trapped substantially within the air system and retained by the containment means when the engine is off. An air / fuel module according to claim 1, comprising a fuel injection system ( 60 ), primarily within the air system ( 14 ) of the housing ( 12 ), wherein the fuel injectors ( 64 ) for injecting a fuel spray through the exhaust ports ( 28 ) of the air system are mounted in the associated engine intake ducts, wherein fuel vapor emissions within the fuel injection system exiting or trapped within substantially contained within the air system and retained by the receiving means when the engine is turned off. The air / fuel module of claim 1, wherein the intake valve is actuated by an actuator responsive to signals indicative of operation and deceleration Display the setting states of the associated motor. The air / fuel module of claim 5, wherein the actuator comprises a first vacuum motor connected to the housing air system and responsive to a vacuum in the air system to open the intake valve, the spring 44 ) closes the valve in the event of a vacuum loss. An air / fuel module according to claim 1, wherein the spring ( 44 ) is a curved spring steel strip.