Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01M—LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
  • F01M13/00—Crankcase ventilating or breathing
  • F01M13/02—Crankcase ventilating or breathing by means of additional source of positive or negative pressure
  • F01M13/021—Crankcase ventilating or breathing by means of additional source of positive or negative pressure of negative pressure
  • F01M13/022—Crankcase ventilating or breathing by means of additional source of positive or negative pressure of negative pressure using engine inlet suction
  • F01M13/023—Control valves in suction conduit
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
  • B01D46/0027—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours with additional separating or treating functions
  • B01D46/0035—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours with additional separating or treating functions by wetting, e.g. using surfaces covered with oil
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
  • B01D46/10—Particle separators, e.g. dust precipitators, using filter plates, sheets or pads having plane surfaces
  • B01D46/12—Particle separators, e.g. dust precipitators, using filter plates, sheets or pads having plane surfaces in multiple arrangements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01M—LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
  • F01M13/00—Crankcase ventilating or breathing
  • F01M13/04—Crankcase ventilating or breathing having means for purifying air before leaving crankcase, e.g. removing oil
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01M—LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
  • F01M13/00—Crankcase ventilating or breathing
  • F01M13/04—Crankcase ventilating or breathing having means for purifying air before leaving crankcase, e.g. removing oil
  • F01M2013/0438—Crankcase ventilating or breathing having means for purifying air before leaving crankcase, e.g. removing oil with a filter

Definitions

• This invention relates generally to the field of emissions control for internal combustion engines, and more particularly to a crankcase ventilation system that recovers hydrocarbon vapors and the like while providing positive crankcase ventilation for reducing blow-by gases.
• lubrication is provided to the pistons within the cylinders by way of the crankcase.
• the piston rings serve to seal the cylinder chamber from the crankcase as the piston travels up and down.
• a perfect seal can never be obtained and, as a result, oil from the crankcase intended for lubricating the cylinder gets drawn into the combustion chamber and burned during the combustion process.
• the concentration of hydrocarbon waste gases in the crankcase is often several times that of the concentration of hydrocarbons in the intake manifold.
• the presence of hydrocarbon gases in the crankcase presents a dilemma: if the gases are freely discharged into the atmosphere, the hydrocarbon waste gases contribute to urban pollution; however, if the waste gases remain trapped in the crankcase, the gases contaminate the lubricating oil and result in degraded oil performance, i.e. the contaminated oil does not lubricate as well as it should, contributing to unnecessary wear of the piston rings, subsequently reducing their ability to seal properly.
• valves have been introduced to recirculate the blow-by gases from the crankcase and into the intake manifold where the gases are re-burned during combustion.
• These valves known as positive crankcase ventilation (PCV) valves, rely on differentials in pressure between the crankcase and the intake manifold to draw the blow-by gases from the crankcase into the intake manifold.
• PCV positive crankcase ventilation
• engine vacuum Because air is drawn into the cylinder combustion chamber through the intake valve as the piston travels downward, the air pressure within the intake manifold is lower than that of the surrounding ambient atmosphere. This is commonly referred to as "engine vacuum" .
• the amount of vacuum varies according to the load upon the engine. When the engine is running at essentially a constant speed, a higher degree of vacuum is present than when the engine is under a loaded condition, such as when accelerating or climbing a hill.
• PCV valves known to date operate similar to a check valve: allowing blow-by gases to be drawn from the crankcase into the intake manifold while preventing gases from the intake manifold to be drawn into the crankcase.
• One common way to implement such a check valve is to provide for a normally closed spring biased valve. At rest, a spring holds an valve member, such as a ball or disk, over an orifice thereby occluding the flow of gases through the orifice. When the air pressure is greater on the valve member than the spring force, the spring is compressed and the valve member is unseated from the orifice, allowing gases to flow.
• U.S. Patent Number 5,228,424 issued on July 20, 1993 to Collins addresses the problem of blow- by gases by providing a two-stage, solenoid-controlled PCV valve.
• U.S. Patent Number 5,228,424 issued on July 20, 1993 to Collins is incorporated in its entirety herein by this reference thereto. While the Collins patent advanced the art to some degree, other important advantages remain to be achieved.
• the vaporized hydrocarbons carried by the blow-by gases are not all the same. Different hydrocarbons having different vapor pressures are present in blow-by. For example, gasoline has a high vapor pressure and is considered volatile while motor oil has a low vapor pressure and does not readily evaporate.
• hydrocarbons with higher vapor pressures are generally more easily burned by the combustion process than those with lower vapor pressures. Further, those hydrocarbons with lower vapor pressures may contribute more to exhaust emissions than the higher vapor pressure hydrocarbons due to incomplete combustion. Additionally, such lower vapor pressure hydrocarbons may usefully add to the lubrication of the engine were they to be returned to the crankcase.
• Collins-type PCV valve may be advantageously augmented with the addition of a magnetic switch directly connected to the throttle.
• throttle positioning can directly determine or can be directly representative of engine load, connecting a controlling and adjustable magnetic switch to the throttle can enhance a Collins-type PCV valve for greater effect.
• a hydrocarbon separator and retriever (the "recovery filter") is introduced in line with the crankcase and the intake-connected PCV valve. Pressured blow-by gases, rich in hydrocarbons and combustion by-products, push into the recovery filter where a filter chamber is filled by an oil- soaked medium having a large surface area, such as metal mesh or wool. Upon encountering the medium, gaseous hydrocarbons and exhaust in the blow-by gas tend to collect upon the medium and its oil-soaked exterior. Generally, the collected hydrocarbons have a lower vapor pressure than those hydrocarbons not "scrubbed" from the blow-by gases by the medium. Scrubbed hydrocarbons tend to collect by gravity at the lower regions of the recovery filter. These hydrocarbons may be drained into the crankcase. Furthermore, noxious vapors such as nitrogen oxides (NOx) and carbon monoxide (CO) are reduced when they pass through the recovery filter, lowering emissions of such gases.
• NOx nitrogen oxides
• CO carbon monoxide
• a Collins-type PCV valve connected to the recovery filter can control the ventilation of the blow-by gases.
• the PCV valve is accurately and adjustably controlled by the throttle position.
• Fig. 1 shows an exploded isometric view of the recovery filter of the present invention, including the filter medium inside the filter chamber.
• the main filter chamber 12 is shown broken mid-way so as to indicate variable length.
• Fig. 2 shows a side cross-section view of the present ventilation system invention including the two-stage PCV valve.
• the main filter chamber 12 is shown broken mid-way so as to indicate variable length.
• Fig. 3 shows a side cross-section view of an alternative embodiment of the ventilation system of the present invention.
• An additional connection is present from the valve cover to the expansion chamber of the inlet cap.
• the main filter chamber 12 is shown broken mid-way so as to indicate variable length.
• Fig. 4 is an exploded isometric view of a two-stage, solenoid-controlled PCV valve that may advantageously be used in the present invention.
• the PCV valve is shown with a housing 52 that may be replaced by the exit nozzle of exit cap 18.
• Fig. 5 is a side cross-section view of the PCV valve of Fig. 4.
• Fig. 6 is a schematic view of the setup and connections s contemplated as made between the PCV valve and the magnetic switch present on the throttle linkage.
• regulated crankcase ventilation is effected by a blow-by gas recovery filter in o line with a PCV valve.
• a blow-by gas recovery filter in o line with a PCV valve.
• Use of the PCV valve provides the necessary regulation of blow-by gases into the intake.
• Use of the recovery filter further lowers engine emission, enhances gas mileage, and reduces engine wear and tear.
• the recovery filter may also prolong the life of the PCV valve.
• a magnetic switch may be coupled directly to the throttle to provide accurate and adjustable engagement of the PCV valve.
• the recovery filter 10 has a o generally cylindrical main filter chamber 12, sized according to the engine to which it is attached.
• a four-cylinder engine could have a recovery filter approximately 7.62 centimeters (3 inches) in diameter by 20.32 centimeters (8 inches) long.
• an expansion chamber of approximately 10.16 centimeters (4 inches) in diameter by 25.54 centimeters (10 inches) in length would provide filtration for the additional cylinders and the blow-by gases generated by them.
• the cylindrical filter chamber 12 may be constructed with any sturdy material that can withstand the environment near an operating engine block. Metals such as steel are recognized as adequate here.
• filtration medium 14 is packed so that a wide expanse of surface area may be presented to blow-by gases passing through the filter chamber 12.
• the filtration medium 14 is such that it provides and enhances the scrubbing abilities of the recovery filter 10, drawing out lower vapor pressure hydrocarbons. Furthermore, the medium 14 aids the reaction of gaseous compounds that can be converted to more inert or less toxic forms, including nitrogen oxides (NOx) and carbon monoxide (CO) .
• NOx nitrogen oxides
• CO carbon monoxide
• Copper wool can provide a large surface area and may have certain chemical properties that aid the hydrocarbon collection and reaction process. As set forth in more detail below, the copper wool is coated with oil before its first use so that its scrubbing ability is enhanced at the outset.
• two caps at either end of the main filter chamber 12 restrictively seal the otherwise open ends.
• the caps 16, 18 may screw or snap fit into the open ends of the filter chamber 12 so that they do not dissociate from the filter chamber 12. Should the copper wool or other filtration medium 14 need changing from time to time, the caps 16, 18 may be temporarily removed to provide access to the filter chamber interior.
• the two caps 16, 18 respectively provide expansion 20 and compression 22 chambers that allow dispersion of the blow-by gases before and after flowing through the filter chamber 12.
• the screens 24, 26 have a mesh size sufficient to freely allow the flow of gases therethrough while holding the filter medium 14 securely within the confines of the filter chamber 12. When the two caps 16, 18 are fitted on either end of the filter chamber 12, the screens 24, 26 may compress the filter medium 14.
• the filter medium 14 should not be packed so tightly as to obstruct gas flow, but should provide as much surface area as possible within the volume defined by the filter chamber 12 for maximum effect.
• the filter medium 14 is spaced apart from the inlet and exit of the filter chamber 12, inlet gases are not focused upon a small area of the filter medium 14 upon entry into the filter chamber 12, and likewise, there is not a small, focused area of filter medium 14 near the exit of the filter chamber 12 past which all gases must flow in order to exit from the filter chamber. In this way, better performance is obtained from the recovery filter 10 as blow- by gases pass through it more easily, and it stands less of a chance from becoming clogged due to the influx of gases heavily laded with recoverable material.
• the inlet cap 16 has a line connecting the expansion chamber to the crankcase so that blow-by gases in the crankcase can flow into the recovery filter 10.
• the inlet line to the recovery filter 28 should be located at a lower end of the inlet cap 16.
• the recovery filter 10 is tilted at an angle of approximately 10 - 15° so that the inlet/drain 30 to the recovery filter 10 is at a lowermost point.
• the recovery filter 10 is filled with motor oil (generally about one-half ( ⁇ ) liter) so that the copper wool may be saturated. The filter is then drained for approximately two (2) hours to remove the excess motor oil.
• the recovery filter 10 is connected as by a line to the crankcase.
• the recovery filter 10 may be mounted not in at an angle, but in a vertical manner such that all recovered liquids flow directly downward into the crankcase.
• an additional inlet 32 into the expansion chamber of the recovery filter 10 may be provided between the expansion chamber 20 and the valve cover of the engine so that dual sources of blow-by gases are connected and flow into the expansion chamber 20 in the ventilation system.
• the PCV valve 40 may be centrally coupled to the outlet cap 18, thereby controlling the flow of gases through the outlet cap 18 and consequently, the recovery filter 10 as well.
• the valve seat 42 of the PCV valve 40 may be against a portion of the outlet cap 18 itself, or an additional housing about which the outlet cap fits. In either configuration, the PCV valve 40 is sturdily and securely associated with the outlet cap 18 so that the two are basically joined as one unit. While an ordinary PCV valve may be used in conjunction with the recovery filter 10 of the present invention, a two-stage Collins-type PCV valve is preferred.
• the positive crankcase ventilation (PCV) valve 40 of the presently preferred embodiment regulates the ventilation of crankcase gases from the crankcase, through the recovery filter 10, and into the intake manifold of an internal combustion engine, such as used in automotive vehicles.
• valve 40 as detailed in exploded view FIG. 4 has an intake orifice 44 connected by way of a suitable conventional means to the recovery filter 10.
• An exhaust orifice 46 is connected to the intake manifold by similar suitable conventional means.
• Crankcase gases are drawn from the crankcase, through the recovery filter 10, into the intake orifice 44 of the valve 40 and vented to the intake manifold by way of the valve's exhaust orifice 46.
• the flow of gases through the valve 40 is regulated by the valve's internal mechanism, the workings of which are set forth in more detail below.
• the PCV valve 40 is encased in a housing having a valve cap 48 where the intake orifice 44, the exhaust tube 50 and the solenoid housing 52 are formed.
• the exhaust tube 50 has a nippled flange 54 surrounding the orifice 14 for attaching the PCV valve exhaust pipe 50 to the engine's intake manifold in a conventional manner.
• a boot 56 fits over solenoid housing 52 to provide a weather-resistant cover and to seal the back end of the PCV valve 40.
• An annular sleeve 58 has a flanged front end 60 that fits within the solenoid housing 52.
• a guide fitting 62 fits within the flanged front end 60 of the annular sleeve 58 to provide an abutting surface for the solenoid plug 64.
• the exterior of the abutting surface 66 fits within the interior of a hollow and closed-ended bobbin 68 that has a front flange 70 and a rear flange 72.
• the rear flange 72 is backed away from the closed rear end of the bobbin 68.
• a washer 74 fits over the rear of the bobbin 68, as does the boot 56.
• Engine vacuum present in the intake manifold causes crankcase blow-by gases to be drawn from the crankcase, through the recovery filter 10, through the PCV valve intake orifice 44 into the PCV valve 40, out of the PCV valve 40 by way of the exhaust orifice 46, and into the intake manifold.
• the flow of crankcase gases through the PCV valve 40 is regulated by the internal mechanism of the valve to provide for a lower degree of venting when the engine is idling (even though manifold vacuum may be very high) and to provide for a higher degree of venting when the engine is loaded or when the engine is cruising at a high speed.
• first disk 80 may have a star-shaped circular appearance, having peripheral vents along the outer circumference of the disk.
• the first disk 80 may be circular in shape with peripheral vents.
• the second disk 82 is of a smaller diameter than the first disk 80.
• the first disk 80 may have a raised circular seat 84 with a diameter equivalent to the diameter of the intake orifice 44 such that when the first disk 80 is held against the orifice 44, only that portion of the disk inside the raised seat 84 is exposed.
• the peripheral vents 86 in the first disk 80 allow gases to flow around the outer periphery of the first disk 80 when the disk's raised seat 84 is unseated from the orifice 44.
• the first disk 80 also has central vents 88 located along the interior region inside of the raised seat's circumference. Gases can flow through these central vents 88 even when disk 80 is seated on orifice 44.
• the second disk 82 is of such a diameter as to occlude the central vents 88 when it is pressed against the first disk, but is sufficiently smaller than the diameter of the first disk so as not to occlude the peripheral vents 86.
• the first and second disks 80 and 82 are supported by a guide rod 90 and are normally biased against the intake orifice 44 by a first compression spring 92 and a second compression spring 94.
• Spring 92 is compressed between disk 82 and snap ring 96 on guide rod 90 and spring 94 is compressed between guide fitting 62 and snap ring 96.
• both rod 90 and disk 82 are biased toward orifice 44 to close same.
• the disks 80 and 82 are retained on a guide rod 90 by way of a first snap ring 98 so that the force of the first spring 92 does not cause the disks to become disengaged from the guide rod 90.
• Disk 80 is held fixed in position on rod 90 by a suitable shoulder on the latter, the disk 82 has an integral hub and is free to slide on rod 90.
• the guide rod 90 is slidingly disposed in a bore through guide fitting 62 and is connected or associated to the solenoid plug 64 within a solenoid bobbin 68 disposed within housing 52.
• the solenoid plug 64 and rod 90 are free to move towards and away from the orifice 44 subject to the pressure differential across disks 80 and 82.
• solenoid plug 64 When the solenoid 100 is energized, solenoid plug 64 is urged towards the orifice 44 by the electromagnetic forces created by the coils of the solenoid to keep disk 80 seated on orifice 44 without regard to the aforesaid pressure differential. Disk 82, however, is still free to move away from the orifice 44 provided there is enough pressure differential across disk 82 to overcome the force of spring 92.
• the solenoid coils are electrically connected to an electrical activation signal by way of connector wires.
• the solenoid is selectively actuated based upon engine throttle position.
• the PCV valve 40 and throttle control 110 are part of an open control loop.
• the throttle position When the throttle position is low, this generally corresponds to a situation where the engine is idling or cruising at a relatively low speed.
• the throttle is in a higher position when the engine is being accelerated or when the engine is cruising at a higher, constant rate of speed.
• the throttle position provides a convenient means by which to determine whether the engine is idling or whether it is accelerating or operating at a constant high speed.
• other means of determining engine speed and load could be utilized.
• a signal could be accessed from the engine computer commonly used to control ignition and spark advance, since throttle position is a control parameter frequently used in engine computers.
• a mechanical position sensor could be utilized, such as a limit switch or potentiometer.
• a magnetic switch 112 may be affixed to one set position and a magnet 114 coupled to the linkage 116 so that the magnet 114 can move its magnetic field about the magnetic switch 112.
• the magnetic switch 112 opens and closes according to the magnetic field strength. As the magnet 114 moves the field, it engages and disengages the PCV valve 40 as appropriate. Adjustment of the magnetic switch 112 is accomplished by physically moving it with respect to the magnet, and vice-versa.
• the magnet 114 can be held in place and the magnetic switch 112 be forced to move by the movement of the throttle linkage.
• Propitious choice of the magnet strength and magnetic switch susceptibility thereto, as well as the physical distance required in order to activate and deactivate the magnetic switch may be made according to the specific circumstances under which the magnetic switch is employed which will advantageously effect the proper operation of the Collins-type PCV valve. Some adjustment may be required upon installation, but it is not contemplated that this should provide any difficulties.
• the ventilation system of the present invention is contemplated as best effected where the PCV valve follows the recovery filter. This allows the PCV valve protection from otherwise filterable materials by the recovery filter that might otherwise injure the PCV valve. Secondly, it prevents the PCV valve from acting as a preliminary filter for the recovery filter and material that might otherwise be collected by the recovery filter will not collect upon the PCV valve where it could interfere with more effective PCV valve operation. Lastly, as the recovery filter drains by gravity into the crankcase, the collected fluids should not flow through the PCV valve as they could interfere with proper PCV valve operation. When the PCV valve is closed, no gases flow through the ventilation system save those that go past the second disk when the intake vacuum or blow-by pressure compress the first compression spring.
• the solenoid in the PCV activates and allows the first disk to retract under pressure from the gases emerging from the recovery filter exit, allowing even more blow-by gases to pass through the filter chamber, the PCV valve, and on into the intake manifold.
• PCV valve and the recovery filter set forth in this system may be used separately, it is contemplated in the present invention that greater advantages are provided to vehicle mileage, engine operation, and that emissions are reduced, when the two are combined in series. Furthermore, there may be circumstances where other types of PCV valve may be advantageously used in conjunction with the recovery filter of the present invention.
• the ventilation system set forth herein provides for better engine operation and lower emissions.
• Preliminary tests on gasoline-powered engines have indicated that the recovery filter reduces nitrogen oxides (NOx) by as much as 25%.
• NOx nitrogen oxides
• the ventilation system of the present invention reduces hydrocarbons and carbon monoxide by as much as 40%, increases gas mileage by as much as 30%, and prolongs engine life by as much as 100%.
• the useful life of spark plugs used in the engine is increased, thereby reducing the necessity for tune-up ⁇ . Oil contamination and sludge build-up are also reduced, extending the time required between oil changes.
• the ventilation system of the present invention can be installed by automobile mechanics and even inexperienced automobile owners in approximately 30 minutes or less.
• the present invention also has applications to diesel engines. While in the United States, diesel-powered trucks and buses account for 10% of all registered vehicles, they account for 40% of the pollution caused by such registered vehicles. Diesel-powered vehicles produce approximately 16 to 21 grams of nitrogen oxide per mile while gasoline- powered vehicles produce less than 1 gram of nitrogen oxide per mile. Preliminary tests of the present invention installed upon a diesel engine show that such diesel engine emissions may be reduced by as much as 40%, increase gas mileage by as much as 25% and prolong engine life by as much as 100%. As with the gasoline-powered engines (above), the ventilation system of the present invention extends the time between oil changes by lessening oil sludge and contamination.
• diesel engines it is best to have a mechanic install the device and such installation can take place in approximately 30 minutes.
• implementation of the present invention on a diesel engine generally requires a connection to a vacuum pump. While gasoline engines provide sufficient vacuum from the intake manifold, diesel engines must substitute a vacuum pump for the intake vacuum.
• the present invention may be applied industrially in conjunction with most internal combustion engines.
• the present invention provides greater engine efficiency and reduces engine emissions.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Lubrication Details And Ventilation Of Internal Combustion Engines (AREA)

Priority Applications (5)

Applications Claiming Priority (1)

Publications (1)

Family

ID=22248469

Family Applications (1)

Country Status (5)

Cited By (4)

Families Citing this family (2)

Citations (7)

• 1995
  • 1995-01-06 AU AU15244/95A patent/AU1524495A/en not_active Abandoned
  • 1995-01-06 JP JP8520928A patent/JPH10511162A/ja active Pending
  • 1995-01-06 WO PCT/US1995/000222 patent/WO1996021101A1/en not_active Application Discontinuation
  • 1995-01-06 CA CA002184980A patent/CA2184980A1/en not_active Abandoned
  • 1995-01-06 EP EP95906786A patent/EP0749526A1/en not_active Withdrawn

Patent Citations (7)

Also Published As

Similar Documents

Legal Events