US3116727A

US3116727A - Crankcase ventilating system

Info

Publication number: US3116727A
Application number: US255884A
Authority: US
Inventors: Howard H Dietrich
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1963-02-04
Filing date: 1963-02-04
Publication date: 1964-01-07
Anticipated expiration: 1981-01-07

Description

Jan. 7, 1964 H. H. DIETRICH CRANKCASE VENTILATING SYSTEM Filed Feb. 4, 1963 A T TORNEV United States Patent O Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Feb. 4, 1963, Ser. No. 255,884 7 Claims. (Cl. 12S-119) This invention relates to crankcase Ventilating systems for internal combustion engines, and more particularly to a crankcase ventilation valve assembly which may be secured to or form a portion of the usual engine carburetor to receive and disperse crankcase fumes and blow-by gases.

In the design and operation of internal combustion engines, and particularly engines for motor vehicles, the elimination or dispersion of crankcase fumes and blow-by gases is becoming more and more important. It has been thought that the crankcase fumes and blow-by gases from the engine are a contributing factor to smog problems in Various regions of the country. It is thus desirable to provide some means for consuming or otherwise eliminating the obnoxious gases during the operation of the engine for the Vehicle.

There are many available crankcase Ventilating systems and crankcase Ventilating Valves. These are generally attached to some portion of the induction system of the engine to convey the crankcase gases to the intake manifold, and thus eliminate the gases by the combustion process in the engine cylinders. Most of these systems and Valves are exceedingly complicated and cumbersome and do not provide complete range control of the crankcase fumes and blow-by gases. For example, many of these devices provide positive crankcase ventilation only during certain conditions of operation of the engine, as under high speed conditions. Others provide positive crankcase ventilation only for low speed operation. A further problem in the generally available crankcase Ventilating valves is in the clogging of the various passages and orifices through which the crankcase fumes and blow-by gases must pass. These orifices are generally of critical size and must be kept clean. They tend to clog with sludge, Varnish formation and other impurities which are carried by the crankcase fumes and are deposited in the small sized metering orifices.

The device in which this invention is embodied comprises, generally, a crankcase Ventilating valve assembly which is operable under all conditions of operation of the internal combustion engine so that crankcase fumes and blow-by gases may be conveyed to the intake manifold at all times. The valve is also provided with a means for maintaining the critical metering orifice in an unclogged condition by means of a pin which is reciprocated into and out of the orifice in accordance with intake manifold vacuum.

With a device of this nature the majority of crankcase fumes and blow-by gases will be consumed and dispersed regardless of engine load or operating conditions, providing more efficient crankcase ventilation for the engine. The metering orifice clean-out means contributeslto this function in assuring proper gas and fume passage through the valve assembly without added restriction.

These and other advantages will become more apparent from the following description and drawing, in which:

FIGURE 1 is an elevational View of a portion of an internal combustion engine, illustrating the various parts thereof;

FIGURE 2 is a cross-sectional View of the crankcase Ventilating Valve assembly embodying this invention and a portion of the carburetor for the engine illustrated in FIGURE 1; and

FIGURE 3 is an isometric View of the metering oriiice lCe clean-out pin which is a part of the Ventilating valve assembly illustrated in FIGURE 2.

Referring more particularly to the drawing, FIGURE l best illustrates a typical internal combustion engine with which the invention may be used. The engine, illustrated generally by the numeral 10, includes the usual engine block 12, having formed therein the conventional engine cylinders and reciprocating pistons which are not shown. Secured to the engine block 12 is a rocker arm cover 14 which is generally a sheet metal member covering the valve operating mechanism for the engine. Secured below the engine block 12 is the usual crankcase 16 in which is located the engine crankshaft and which also serves as a reservoir for the engine oil. Mounted on the side of the engine block 12 is an intake manifold 18 having ram tubes or pipes 20 which communicate with the engine cylinders through the intake valves in the normal fashion. Adjacent intake manifold 18 is an exhaust manifold 22 to which is secured an exhaust pipe 24 for conveying exhaust gases from the cylinder to the usual mufiier and tailpipe assembly.

Mounted above the intake manifold 18 is a carburetor, illustrated generally by the numeral 26, which provides for the proper air and fuel mixture conveyed to the engine cylinders through the intake manifold 18. Mounted above carburetor 26 is an air cleaner-silencer assembly 28 to receive and filter the incoming air for passage to the engine.

Disposed adjacent to the carburetor 26, or forming a part thereof, is the crankcase Ventilating Valve assembly, illustrated generally by the numeral 36. A tube or conduit 32 communicates between the engine crankcase 16 and the valve assembly 3b. It is to be understood that the tube 32 need not be secured directly in the crankcase but could just as well be secured in any other part of the engine where crankcase fumes and blow-by gases circulate. For example, tube 32 could alternatively be secured in the rocker arm cover 14.

Referring now to FIGURE 2, the crankcase Ventilating Valve 3) and its Various parts are best illustrated. The carburetor 26 includes a throttle Valve 34 mounted on a pivot pin 35 which is suitably secured in the carburetor throat 38. The carburetor is shown to be mounted on the intake manifold 13 by bolts 4i) although any suitable mounting may be provided.

Located adjacent carburetor throat 38 is a housing 42 containing an accumulator chamber 44. Housing 42 may be an integral portion of the carburetor 26, as illustrated in FIGURE 2, or may be a separate housing secured to the carburetor 26 in any suitable fashion. The housing 42 is closed by a second housing member 46 secured thereto in any suitable fashion and which receives an inlet tube 43. Inlet tube 4S is suitably secured to the crankcase tube 32 and serves as an inlet to the Ventilating valve assembly 30. Tube 48 is provided with an inclined end 50 for purposes to be later described. A transverse outlet aperture 52 is provided in the tube 48 adjacent and spaced from the inner end 50.

Housing 46 also has a passage S4 formed therein which is in registry with the aperture 52 formed in the inlet tube 48. The passage 54 communicates with another passage 56 formed through the wall of the carburetor 26, the passages S4 and 56 being separated by a metering orifice 58.

Also formed in housing portion 46 and with a cover member 6) is a hollow chamber 62 located adjacent the metering orifice 58. Chamber 62 is divided into two portions by a movable partition 64 which may take any convenient form, such as a disk spring or a movable diaphragm. One portion of the chamber 62 communicates with the atmosphere through passage 66 and the other portion of chamber 62 communicates with the passage 56 through a suitable passageway 68 formed in the housing 42, housing member 46 and the cover means 60. It is thus seen that the right-hand portion of the chamber 62 will be maintained at the same pressure as that of passage 56 and the intake manifold.

Secured to the movable partition 64 is the metering orifice clean-out pin, indicated generally by the numeral 70. This pin is best illustrated in FIGURE 3 and is shown to include a shank portion 72 extending from an enlarged head 74 and terminating in an annular edge 76. Adjacent edge 76 is a portion 77 of reduced diameter to permit flow around the pin. Pin 70 is secured in any suitable manner to the movable partition 64 and is shown in FIGURE 2 to extend into the metering orifice 58. It may be seen that as the partition 64 moves from left to right, as Viewed in FIGURE 2, in response to intake manifold vacuum and further by the biasing of spring 73, the `cutting edge 76 of the pin 70 will be withdrawn from the metering orifice 58, and upon movement of the partition in the opposite direction the cutting edge 76 of the pin 70 will again enter and ream the metering orifice 58.

Mounted in the chamber 44 of housing portion 42 is a check Valve, illustrated generally by the numeral 80. Valve 8f) is of suflicient size to cover the end 50 of the inlet tube 48 and is pivotally secured in the chamber 44 by means of pivot pin 82. Pivot pin 82 is received in a bifurcated block 84 secured to the housing member 46 and in the chamber 44 by means of suitable bolts or screws 86.

Extending from the chamber 44 through the wall of the carburetor 26 and into the induction passage 38 is an ejector tube 88, the purpose for which will be later described.

T he operation of the crankcase Ventilating valve assembly will be described as follows. Considering first the condition wherein the engine is operating at high load, for example, with the throttle valve 34 one-half open or more, as in the position shown in dashed and dotted lines in FIGURE 2, the intake manifold depression will be relatively low and blow-by in the engine cylinders will be relatively high. Assume for purposes of discussion that the pressure is inches of mercury or below in the intake manifold 18 under this condition of operation. With such vacuum pressure in the intake manifold, which Vacuum will be conveyed to the inlet tube 48 through the passages S6 and 54, the check valve 80 will be in an open position, that is, as illustrated in dashed and dotted lines in FIGURE 2. Crankcase fumes and blow-by gases will thus be drawn through the tube or pipe 32, the inlet tube 48 and'past the check valve 80 to the accumulator chamber 44. Air flowing past the injector tube 88 will create an additional ejector effect to draw the crankcase fumes and blow-by gases from the accumulator to the carburetor induction passage 38 and into the intake manifold.

Assuming now the engine is operating at light engine load, that is, where the throttle valve 34 may be one-half open or less, the intake manifold depression will be relatively high, for example, at 15 to 18 inches of mercury. This suction or Vacuum pressure conveyed through passages 56 and 54 is sufficient to close or partially close check valve 80 and thus close the end of the intake tube 48 requiring the crankcase fumes and blow-by gases to be conveyed through the passages 54 and 56, through the metering orifice 58 and into the induction passage 38 of the carburetor 26 below the throttle valve 34. Thus, at light and idle load the crankcase fumes and blow-by gases are ejected into the intake manifold without adversely affecting the carburetion characteristics of the engine.

Considering now the effect of engine operation on the metering orifice clean-out means, the movable partition 64 is shown in full lines in the position it would assume under high engine load, that is, 15 inches of mercury and below in the intake manifold. Under these conditions the crankcase fumes and blow-by gases are conveyed past the check valve 80 and into the induction passage 38 above the throttle valve 34. However, upon decreasing the engine load or closing the throttle 34 the intake manifold depression builds to cause the movable partition 64 to be drawn to the right as Viewed in FIGURE 2, withdrawing the pin 70 from the metering orifice 58. The partition 64 and pin 70 are held in this position until the engine load changes, at which time manifold depression `decreases and the flow is again through the accumulator chamber 54. The movable partition 64 will again move to the left as Viewed in FIGURE 2, and the cutting edge 76 of the clean-out pin 70 will ream metering orifice 58 thus keeping it free of :sludge and Varnish deposits. This operation is automatic, being dependent upon the amount of Vacuum in the inlet manifold 18 during various conditions of operation of the engine.

`Contributing greatly to the efficiency and operation of the Ventilating valve assembly 30 is the position of the check valve Si), that is, the pivot pin 82 must be properly positioned bot-h vertically and horizontally within the accumulator chamber 44. Furthermore, the angle of the end 5t) of the inlet tube 48 s important. The proper combination of pivot pin location and tube end angle provides a linear flow through `the metering orifice 58 when the check valve 80 is open, that is, linear with respect to manifold depression because of the modulated position of the check valve 8f). This is extremely desirable for efficient operation of the Ventilating valve assembly.

Thus, a crankcase Ventilating system is provided which is `operable under all conditions of engine operation for better dispersal and elimination of obnoxious fumes from the engine. The Ventilating Valve assembly is operable under both high and low engine load conditions, being dependent upon manifold depression for its actuation. Proper carburetion characteristics are retained through the use of a metering orifice which will not become clogged or fouled `due to the passage of fumes and blowby gases therethrough.

What is 4claimed is:

l. `Crankcase Ventilating means for an internal combustion engine having a carburetor including a throttle valve and an inlet manifold and comprising:

a valve body connected to said carburetor and having first and second outlet means, said first outlet means communicating with said carburetor upstream of said throttle valve, said second outlet means communicating with said carburetor downstream of said throttle valve and including a metering orifice;

conduit means communicating between said crankcase and said valve body and communicating with said first and second outlet means;

a check Valve in said first outlet means and operable in accordance with the amount of suction in said inlet manifold to direct crankcase gases through either said first outlet means or said second outlet means;

and vacuum operated means for cleaning said metering orifice, said means being operable in accordance with the amount of suction in said inlet manifold.

2. A crankcase Ventilating device for an internal combustion engine having an inlet manifold and a carburetor including a throttle valve and comprising:

a valve body adapted to be secured to said carburetor, said valve body having an inlet land first and second outlets, said first outlet communicating with said carburetor upstream of said throttle valve and said second outlet communicating with said carburetor downstream of said throttle Valve land having a metering orifice therein;

a check Valve mounted in said valve body and in said first outlet, said check valve being operable in accordance with the vacuum pressure in said inlet manifold to direct incoming gases through either said first or second outlet depending on said vacuum pressure;

conduit means communicating between said engine crankcase and said inlet in said Valve body;

and vacuum responsive means for cleaning said metering orifice in said second outlet, said means including a chamber formed in said valve body and a pin extending from said chamber and into said metering orifice and spring means in said chamber and secured to said pin and movable in response to manifold vacuum to move said pin into and out of said metering orifice.

3. In a crankcase Ventilating valve for an internal combustion engine yand having a metering orifice in an outlet therefrom, means for cleaning said metering orifice comprising:

a housing having a chamber formed therein;

a pin member having an enlarged head disposed in said chamber land extending from said chamber and into said metering orifice;

a disk spring in said chamber secured at the center thereof to said enlarged head and secured at the edges thereof in said housing yand vdividing said chamber into two portions;

latmospheric vent passage means in said housing and communicating with one of said chamber portions;

and passage means in said housing and communicating between the inlet manifold of said engine and the other of said chamber portions;

said disk spring and said pin member being ,axially movable in accordance with the manifold vacuum in said engine to permit said pin to clean said metering orifice.

4. In a crankcase Ventilating valve for an internal combustion engine having an outlet therefrom and a metering orifice in said outlet, means for cleaning said orifice comprising:

a housing having a chamber formed therein;

movable partition means in said chamber and dividing said chamber into two portions;

passage means in said housing and communicating between one portion of said chamber and an inlet manifold of said engine `and adapted to evacuate a portion of said chamber and move said partition means in response to vacuum pressure in the inlet manifold;

and a clean-out pin extending Ifrom said chamber and into said metering orifice, said pin being secured to said movable partition and movable therewith into tand out of said metering orifice in accordance with the vacuum in the intake manifold of said engine.

5. A crankcase Ventilating system for an interna-l combustion engine having an inlet manifold and a carburetor having a throttle valve and comprising:

a housing having an inlet and first and second outlets, `said inlet communicating with the crankcase of said engine, said first outlet communicating with said intake manifold upstream of said throttle valve and said second outlet communicating with said intake manivfold downstream of said throttle valve;

a check valve in said housing and operable to close said first outlet when the vacuum in said intake manifold is above a predetermined value;

a metering orifice in said second outlet to control flow of crankcase gases therethrough;

and means for periodically cleaning said metering orifice, said means including a pin reciprocab'le into and out of said orifice 'in response to intake manifold vacuum in said engine.

6. The crankcase Ventilating system set forth in claim 5 wherein said means for cleaning said metering orifice further include a chamber formed in asid housing and having a movable partition therein to divide said chamber into two portions, one of said portions being in communication with said second outlet means for evacuating said one of said portions, and said pin being secured to said movable partition for reciprocation into and out of said metering orifice.

7. The crank case Ventilating system set forth in claim 6 wherein said movable partition comprises a disk spring adapted to snap overcenter in either direction in accordance lwith the vacuum in said inlet manifold.

References Cited in the file of this patent UNITED STATES PATENTS Winkler Nov. 22, 1944

Claims

1. CRANKCASE VENTILATING MEANS FOR AN INTERNAL COMBUSTION ENGINE HAVING A CARBURETOR INCLUDING A THROTTLE VALVE AND AN INLET MANIFOLD AND COMPRISING: A VALVE BODY CONNECTED TO SAID CARBURETOR AND HAVING FIRST AND SECOND OUTLET MEANS, SAID FIRST OUTLET MEANS COMMUNICATING WITH SAID CARBURETOR UPSTREAM OF SAID THROTTLE VALVE, SAID SECOND OUTLET MEANS COMMUNICATING WITH SAID CARBURETOR DOWNSTREAM OF SAID THROTTLE VALVE AND INCLUDING A METERING ORIFICE; CONDUIT MEANS COMMUNICATING BETWEEN SAID CRANKCASE AND SAID VALVE BODY AND COMMUNICATING WITH SAID FIRST AND SECOND OUTLET MEANS; A CHECK VALVE IN SAID FIRST OUTLET MEANS AND OPERABLE IN ACCORDANCE WITH THE AMOUNT OF SUCTION IN SAID INLET MANIFOLD TO DIRECT CRANKCASE GASES THROUGH EITHER SAID FIRST OUTLET MEANS OR SAID SECOND OUTLET MEANS; AND VACUUM OPERATED MEANS FOR CLEANING SAID METERING ORIFICE, SAID MEANS BEING OPERABLE IN ACCORDANCE WITH THE AMOUNT OF SUCTION IN SAID INLET MANIFOLD.