US3673994A - Crankcase blow-by gas recirculating device - Google Patents

Abstract

A crankcase blow-by gas recirculating device which is adapted to interrupt the recirculation of the blow-by gases from the engine crankcase to the combustion chambers during deceleration and idling when the quantity of unburned hydrocarbons in the engine exhaust gases significantly increases, which device is provided with flow regulating means comprising a valve element operatively interposed in the blow-by gas recirculating passage and means detecting the decelerating and idling conditions and actuating the valve element when the decelerating or idling condition is detected. Such decelerating and idling conditions may preferably represented by the angular position of the throttle valve, vacuum in the intake manifold, vehicle speed, or any combination of these. The device of the invention may be used in combination with an internal combustion engine having a carburettor or having, in lieu of the carburettor a fuel injection system.

Description

United States Patent 1151 3,673,994

Aono 1 July 4, 1972 [541 CRANKCASE BLOW-BY GAS 3,368,345 2/1968 Walker ..123/119 B x RECIRCULATING DEVI E 2,064,720 12/1936 Balogh ..123/119 B 3,473,521 10/1969 Mustainetal. ...123/1l9B [72] Inventor: Shigeo Aono, Yokosuka, Japan 3,161,187 12/1964 Parker ..123/1 19 B [73] Assignee: Nissan Motor Company, Limited,

Yokohama, Ja an Primary Examiner-Wendell E. Burns Assistant Examiner-Ronald H. Lazarus Filed: June 30, An0rney ']ohn Lezdey 121] App] No: 51,293

[57] ABSTRACT r, i Wig hpviimfim, p m A crankcase blow-by gas recirculating device which is adapted to interrupt the recirculation of the blow-by gases from the enjlly W99 Japan "44/52472 gine crankcase to the combustion chambers during deceleration and idling when the quantity of unburned hydrocarbons [52] US. Cl. ..123/1l9 B, 123/97 B in the engine exhaust gases Significantly increases which [51] llil. Cl ..F02Ill device is provided i n regulating means comprising a Fleld of Search B, B, valve element operativeiy interposed in the y g recir 137/480 culating passage and means detecting the decelerating and 56 R f d idling conditions and actuating the valve element when the 1 e erences l e decelerating or idling condition is detected. Such decelerating UNITED STATES PATENTS and idling conditions may preferably represented by the angular positlon of the throttle valve, vacuum 1n the intake whlttingtonu X manifold vehicle peed o any combination of these The Guarnaschelll B device ofthe invention may be used in combination with an in. GeOffiOy B ternal combustion engine having a carburettor or having in 2,255,351 9/1941 Dresslel' B lieu ofthe carburettor a fuel injection system. 3,416,503 12/1968 High .....123/119 13 2,154,593 4/1939 Way ..123/119 B 5 Claims,6 Drawing Figures PATENIEDJUL "4 I972 SHEEI 10F 4 INVENTOR SHIGEO AONO BY ATTORNEY PATENTEDJUL "4 I972 SHEET 2 [IF 4' INVENTOR SHIGEO AONO BY TTOR PATENTEUJUL 41972 I saw u or. "4

NVENTOR CRANKCASE BLOW-BY GAS RECIRCULATING DEVICE This invention relates to an automotive intemal combustion engine, and more particularly to an improved crankcase blowby gas recirculating device which is adapted to reduce the quantity of hydrocarbons contained in the engine exhaust gases.

During operations of an internal combustion engine a certain amount of combustion gases escape into the crankcase. Such escaped gases, which are usually called blow-by gases," are known to be one of the major sources of air pollution. It is, thus, known that the air pollution by motor vehicles can be considerably eliminated by recirculating the blow-by gases to the intake side of the engine, where the blow-by gases are mixed with the supplied air-fuel mixture. The blow-by gases are usually led either to the carburettor upstream of the throttle valve or direct to the intake manifold. In any event, however, during idling and decelerating operations, the blow-by gases which have developed in the crankcase and containing a relatively great quantity of hydrocarbons are drawn into-the combustion chambers of the engine, with the increased vacuum obtaining downstream'of the throttle valve during those operations. Consequently, the mixture the air-fuel ratio of which is determined by thespecific type and construction of thecarburettor or the fuel injection system, is enriched with additional hydrocarbons contained in the blow-by gases admixed thereto, causing unsatisfactory combustions such as misfiring in the combustion chambers. Such unsatisfactory combustion of the air-fuel mixture results in an emission of exhaust gases containing an increased quantity of hydrocarbons. In an internal combustion engine provided with a system which is adapted to shut ofi the supply of mixture through the slow running mixture passage during decelerating operation so as to eventually reduce the hydrocarbon content in the engine exhaust gases, if the blow-by gases containing a large amount of hydrocarbons are mixed up with air drawn in through the engine air cleaner during decelerating operation, the hydrocarbons contained in the blow-by gases will be remain unburned in the exhaust gases.

It is, therefore, the primary. object of the present invention to provide a device adapted to interrupt the recirculation of the blow-by gases from crankcase to the intake manifold during idling and decelerating operations of the automobile, whereby the air pollution resulting from the emission of increased amount of unburned hydrocarbons in the engine exhaust gases can be considerably eliminated.

In order to accomplish such an object, the invention proposes to provide the blow-by gas recirculating passage with a flow regulating device which is adapted to close the recirculating passage during decelerating and idling operations. The device to be used for this purpose is so constructed and arranged as to operate in relation to the angular position of the carburettor throttle valve or the vacuum in the intake manifold. If desired, the flow regulating device may be of the type which is operable on both the angular position of the carburettor throttle valve and the vehicle speed.

In the drawings:

FIG. 1 is a schematic view partially in section of an internal combustion engine incorporating the improvement according to this invention;

FIGS. 2, 3 and 4 are schematic sectional views of embodiments of this invention;

FIG. 5 is charts showing the relationships between the throttle valve'opening which is dictated by the angular position of the carburettor throttle valve (A); engine speed (B); intake manifold vacuum (C); voltage generated for controlling the device of the invention in one embodiment (D): and quantity of hydrocarbons contained in the engine exhaust gases (E), all indicated in terms of the time elapsed; and

FIG. 6 is a schematical sectional view of a portion of the internal combustion engine provided with the fuel injection system, incorporating this invention.

Referring now to FIG. 1, there is shown an internal combustion engine 10 having a carburettor 11 with an air cleaner 12, a venturi 13 and a throttle valve 14. Air is drawn into the carburettor 11 through the air cleaner 12, and is mixed up with fuel in the carburettor 11. The airfuel mixture thus produced is then drawn into a combustion chamber 15 of the engine through an intake manifold 16. A crankcase is mounted as denoted by numeral 17, from which a blow-by gas recirculating passage 18 leads back to the combustion chamber through the intake manifold. The passage 18, which is shown to be opened into the-intake manifold 16, may be opened into the carburettor 11 upstream of the throttle valve 14, if desired.

According to this invention, means for regulating the flow of the blow-by gases recirculated through the passage 18 is provided, which flow regulating means, as represented by numeral 19, is interposed operatively in the passage 18 as seen in FIG. 1 and is arranged in a manner to normally keep the passage 18 open and to close the passage 18 during deceleration and idling when the throttle valve 14 is substantially closed.

The flow regulating means 19 is so constructed as to operate in relation to any of those conditions which will provide deceleration or idling of the vehicle, such as the angular position of the throttle valve, vacuum in the intake manifold, vehicle speed, and any combination of these.

FIG. 2 illustrates an example of the flow regulating means which is operable on the angular position of the throttle valve. As shown, the flow regulating means, which is generally represented by numeral 194, comprises a valve element 20 which is operatively interposed in the passage 18 and means 21 for detecu'ng the decelerating and idling conditions and actuating the valve element 20 to move into a position to close the passage when either of the decelerating and idling conditions is detected. The detecting and actuating means 21 is largely constituted by a mechanical linkage operatively connecting the valve element 19 to the throttle valve 14. This mechanical linkage 21 comprises a movable arm 22 connected to the throttle valve 14 and moved as the throttle valve rotates. A connecting rod 23 is operatively connectedat one end to the arm 22 and pivotally mounted at a suitable position 230 thereof. An actuating rod 24 is operatively connected at one end to the other end of the connecting rod 23 and secured at the other to the valve element 20.

The valve element, which is itself may be constructed in a suitable manner, is shown as a spool valve having a central groove 20a and a land 20b adjacent thereto.

When, in operation, the vehicle is accelerating or normally cruising with the throttle valve 14 fully or partly open, then the valve element 19 is held in a position in which the passage 18 is opened through the groove 20a thereof, as shown in FIG. 2

During deceleration or idling when the throttle valve 14 is substantially fully closed, then the arm 22 is rotated together with the throttle valve 14 so that the connecting rod 23 is rotated about the pivotal point 23a, causing the valve element 19a to move into a position to close the passage 18 by the land 20b.

FIG. 3 illustrates another example of the blow-by gas flow regulating means which is operable on the angular position of the carburettor throttle valve.

As shown, the modified flow regulating means which is now represented by numeral 19b, is essentially comprised by a valve element which is similar to the valve element 20 and is therefore denoted by the same numeral and an electrical linkage which is arranged not only to detect the angular position of the throttle valve 14 but to actuate the valve element 20 when such an angular position of the throttle valve as to provide decelerating or idling condition is detected. The electric linkage comprises means 25 sensing the angular positions of the throttle valve 14 and generating a signal voltage when the angular position at which the throttle valve is substantially closed is sensed and a solenoid device 1912 which is adapted to move the valve element 20 when energized by the means 25 sensing the angular position of the throttle valve. The solenoid device 19b is made up of a solenoid coil 26 connected through a line 27 to the means 25 and a moving core 28 rigidly connected to the valve element 20. The moving core 28 is normally held, by the action of a spring 29, in a position in which the valve element 20 opens the passage 18 and, when the solenoid coil 26 is energized with a voltage supplied from the means 25, held against the action of the spring 29 in a position in which the valve element 20 closes said passage.

If desired, the means 25 may be connected to a suitable sensor 30 which is adapted to sense the speed at which the vehicle is driven. In this instance, the solenoid coil 26 will be energized when the throttle valve 14 is substantially closed and when a predetermined vehicle speed is reached. The provision of such sensor 30 will prove advantageous especially where the carburettor is provided with a slow running mixture passage.

As previously discussed, the blow-by gas flow regulating means may be constructed so as to operate in response to the vacuums in the intake manifold of the engine, an example being illustrated in FIG. 4.

As seen in FIG. 4, the flow regulating means, which is generally designated by numeral 190, comprises a vacuum passage 31 communicating with the intake manifold 16 of the engine through a port 32 and a diaphragm device 33 which includes a diaphragm member 34 exposed on one side to the intake manifold vacuum through the vacuum passage 31 and an actuating rod connecting the diaphragm member 34 to the valve element 20. The diaphragm member is normally held by the action of a spring 36 in a position to hold the valve element 20 to open the passage 18 and, when the vacuum in the intake manifold reaches a predetermined level, moved against the action of the spring 36 to a position to cause the valve element 20 to close the passage 18.

The operations and the operational features of the blow-by gas flow regulating means previously described will be better understood with reference to FIG. 5. When the throttle valve is closing from full throttle position to closed position, as seen in (A) of FIG. 5, the engine speed decreases gradually as seen in (B), the vacuum downstream of the throttle valve abruptly increases and then gradually decreases as the engine speed decreases as seen in (C), and the quantity of the hydrocarbons in the engine exhaust gases emitted from a conventional engine varies as indicated by a solid curve in (E). The quantity of the hydrocarbons emitted from the engine incorporating the improvement according to this invention varies as indicated by a dashed curve of (E). The graph (D) in FIG. is presented to show how the signal voltage is generated by the means 25 in the second embodiment of the invention.

The invention has been heretofore discussed in relation to an internal combustion engine provided with the carburettor. Naturally this invention can also be applied to an internal combustion engine provided with a fuel injection system in lieu of a conventional carburettor to supply fuel to the engine.

In FIG. 6, a schematical sectional view of a portion of the internal combustion engine provided with a fuel injection system incorporating this invention is shown.

In the drawing, the flow regulating means represented by 19b is constructed similarly to the means 19b of FIG. 3 and, therefore, like elements are denoted by like numerals. Any other element which has the same construction and operation as that in FIG. 3 is shown by the same numeral.

The fuel injection system 37 consists of means 38 which detects various variables of the driving condition of the vehicle such as the angular position of the throttle valve, the vacuum downstream of the throttle valve, or the engine speed and which feeds fuel through an injection pipe 39 and injection valve 40 to an injection nozzle 41 in dependence upon the thus detected viriables. Fuel is injected from the injection nozzle 41 into the intake manifold 16 to be mixed with incoming air.

What is claimed is:

1. In an internal combustion engine for use with an automotive vehicle, including in combination a throttle valve, an intake old, a plurahty of combustion chambers, a crankcase, and a blow-by gas recirculating passage for providing communication between the interior of the crankcase and each of the combustion chambers through the intake manifold to introduce the blow-by gas gases to each of the combustion chambers to thereby prevent the blow-by gases from being emitted to the surrounding atmosphere, the improvement comprising:

on-ofi' control solenoid valve means for on-off controlling the flow of the blow-by gases to be introduced to the combustion chambers, said solenoid valve means including a valve element interposed in the recirculating passage and normally held in an open position to allow said communication, said valve element having a spool shape for abruptly shutting off said communication when moved into its closed position concurrently upon the actuation of said valve means; and

detecting means detecting the running conditions of the vehicle for actuating said solenoid valve means only when the engine is driven by the vehicle itself.

2. An improved internal combustion engine according to claim 1, wherein said detecting means includes sensing means for sensing the angular position of said throttle valve for generating a voltage signal when said throttle valve is substantially closed, and wherein said solenoid valve means further includes a solenoid device connected to said valve element for moving the same into said closed position when energized by said voltage signal.

3. An improved internal combustion engine according to claim 2, wherein said solenoid device includes a solenoid coil electrically connected with said sensing means, a moving core rigidly connected to said valve element, and a coil spring biasing the assembly of said moving core and valve element for normally holding said valve element in said open position, the spring action of said coil spring being preset to yield to the extracting force of said solenoid coil which is exerted to said assembly by said solenoid coil.

4. An improved internal combustion engine according to claim 1, wherein said detecting means includes sensing means for sensing the angular position of said throttle valve and the vehicle speed for generating a voltage signal when said throttle valve is substantially closed and when said engine speed exceeds a predetermined level, and wherein said solenoid valve means further includes a solenoid device connected to said valve element for moving the same into said closed position when energized by said voltage signal.

5. An improved internal combustion engine according to claim 4, wherein said solenoid device includes a solenoid coil electrically connected with said sensing means, a moving core rigidly connected to said valve element, and a coil spring biasing the assembly of said moving core and valve element for normally holding said valve element in said open position, the spring action of said coil spring being preset to yield to the extracting force of said solenoid coil which is exerted to said assembly by said solenoid coil.

W 1 i i i

Claims (5)

1. In an internal combustion engine for use with an automotive vehicle, including in combination a throttle valve, an intake manifold, a plurality of combustion chambers, a crankcase, and a blow-by gas recirculating passage for providing communication between the interior of the crankcase and each of the combustion chambers through the intake manifold to introduce the blow-by gas gases to each of the combustion chambers to thereby prevent the blow-by gases from being emitted to the surrounding atmosphere, the improvement comprising: on-off control solenoid valve means for on-off controlling the flow of the blow-by gases to be introduced to the combustion chambers, said solenoid valve means including a valve element interposed in the recirculating passage and normally held in an open position to allow said communication, said valve element having a spool shape for abruptly shutting off said communication when moved into its closed position concurrently upon the actuation of said valve means; and detecting means detecting the running conditions of the vehicle for actuating said solenoid valve means only when the engine is driven by the vehicle itself.

2. An improved internal combustion engine according to claim 1, wherein said detecting means includes sensing means for sensing the angular position of said throttle valve for generating a voltage signal when said throttle valve is substantially closed, and wherein said solenoid valve means further includes a solenoid device connected to said valve element for moving the same into said closed position when energized by said voltage signal.

3. An improved internal combustion engine according to claim 2, wherein said solenoid device includes a solenoid coil electrically connected with said sensing means, a moving core rigidly connected to said valve element, and a coil spring biasing the assembly of said moving core anD valve element for normally holding said valve element in said open position, the spring action of said coil spring being preset to yield to the extracting force of said solenoid coil which is exerted to said assembly by said solenoid coil.

4. An improved internal combustion engine according to claim 1, wherein said detecting means includes sensing means for sensing the angular position of said throttle valve and the vehicle speed for generating a voltage signal when said throttle valve is substantially closed and when said engine speed exceeds a predetermined level, and wherein said solenoid valve means further includes a solenoid device connected to said valve element for moving the same into said closed position when energized by said voltage signal.

5. An improved internal combustion engine according to claim 4, wherein said solenoid device includes a solenoid coil electrically connected with said sensing means, a moving core rigidly connected to said valve element, and a coil spring biasing the assembly of said moving core and valve element for normally holding said valve element in said open position, the spring action of said coil spring being preset to yield to the extracting force of said solenoid coil which is exerted to said assembly by said solenoid coil.

Images