US3704698A

US3704698A - Notched door valve for control of carburetor air and crankcase vapors

Info

Publication number: US3704698A
Application number: US101228A
Authority: US
Inventors: Jorma O Sarto; Gary D Dawson
Original assignee: Chrysler Corp
Current assignee: Old Carco LLC
Priority date: 1970-12-24
Filing date: 1970-12-24
Publication date: 1972-12-05
Anticipated expiration: 1989-12-05
Also published as: CA939572A

Abstract

An air cleaner snorkel having an inlet for heated air in addition to the usual ambient air inlet at its open end and also including an inlet for vapors from the crankcase. A door-like valve controls the flow of ambient and heated air through the snorkel into the air cleaner. The door is notched to assure the presence of at least a small amount of ambient air flow through the snorkel when the door is closed or partially so with respect to the ambient air inlet thereby directing vapors from the crankcase into the air cleaner and preventing their escape out of the ambient air inlet to the atmosphere.

Description

United States Patent Sarto et al.

[54] NOTCHED DOOR VALVE FOR CONTROL OF CARBURETOR'AIR AND CRANKCASE VAPORS [72] Inventors: Jorma O. Sarto, Orchard Lake; Gary D. Dawson, Rochester, both of 21 Appl. No.: 101,228

[52] US. Cl. ..123/l19 B, 123/122 D [51] Int. Cl. ..B0ld 39/10, F02m 23/14, F02f 9/02 [58] Field oiSearch 123/122 D, 119 B 1 [56} References Cited UNITED STATES PATENTS 2/1957 Sebok et a1. ..l23/122 D 1/1958 Dolza ..l23/122 D [451 Dec.5, 1972 Scott ..123/122 D X Primary Examiner-Wendell E. Burns Attorney-Talburtt & Baldwin [5 7 ABSTRACT An air cleaner snorkel having an inlet for heated air in addition to the usual ambient air inlet at its open end and also including an inlet for vapors from the crankcase. A door-like valve controls the flow of ambient and heated air through the snorkel into the air cleaner. The door is notched to assure the presence of at least a small amount of ambient air flow through the snorkel when the door is closed or partially so with respect to the ambient air inlet thereby directing vapors from the crankcase into the air cleaner and preventing their escape out of the ambient air inlet to the atmosphere.

5 Claims, 4 Drawing Figures PATENTEUBEB 5 I972 v sum 1 OF 2 INVENTgLi 77% J47 0 7 Z llama)! PATENTED DE 5 I97? 3. 704,698

sum 2 or 2 2-4:. 1% INVENTORS.

NOTCHED DOOR VALVE FOR CONTROL OF CARBURETOR AIR AND CRANKCASE VAPORS BACKGROUND This invention relatesto crankcase ventilating arrangements and a means for preventing the loss of crankcase vapors to the atmosphere. Certain crankcase ventilator arrangements make use of a crankcase inlet conduit or back-up tube which communicates between the crankcase and the carburetor air cleaner snorkel. At certain times during engine operation this conduit carries fuel-rich vapors from the crankcase to the snorkel.

Certain air cleaners today make use of heated inlet air to permit the use of leaner fuel-air mixtures. Such arrangements include an extra air inlet into the snorkel for the heated air. A sheet metal stoveis bolted over 0 the inlet manifold that is a downstream portion of the I the exhaust manifold and air drawn therebetween for heating is carried to the snorkel by a suitable conduit. A thermostatically controlled-vacuum operated doorlike air valve controls the air temperature to a predetermined temperature, such as l00F.

When these arrangements are combined into one system there is some danger of the loss of crankcase vapors out the open end of the snorkel. It is the purpose of this invention to prevent such losses.

SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic showing of a closed engine ventilator system including inlet and outlet ventilator conduits to the crankcase from different parts of the engine induction system; the inlet conduit or back-up tube extending between the carburetor air cleaner snorkel and one crankcase inlet passage is arrangedas part of the improved combination according to this invention.

FIG. 2 is a schematic showing of a heated inlet air system including the manifold heating arrangement and the vacuum operated thermostatic control for the air control valve.

FIG. 3 is a side view, partly in section, of a carburetor air cleaner snorkel body showing the air control valve in the closed position relative to the ambient air inlet and also showing the preferred location for the point of attachment of the back-up tube to the snorkel body.

FIG. 4 is a plan view of FIG. 3 with portions removed to show the apertured air control valve.

DESCRIPTION OF THE PREFERRED EMBODIMENT Closed crankcase ventilation systems have been used on many automobiles for several years. Such a system is described in detail in SAE Paper No. 700150, entitled Chrysler Evaporation Control System, The Vapor Saver for 1970, by J. O. Sarto, W. S. Fagley and W. A. Hunter and in SAE Paper No. 700151, entitled The Chrysler Cleaner Air System for 1970, by R. E. Goodwillie, N. M. Jacob and E. W. Beckman. In such a system the inlet and outlet ventilation passages or conduits to the crankcase are connected to the engine induction system. The crankcase inlet ventilator conduit extends between the air cleaner, which represents an upstream portion of the induction system, and an inlet passage into the crankcase, such as the crankcase air cleaner. The crankcase outlet ventilator conduit extends between another crankcase outlet passage and induction system. Under engine operating conditions, of light load, air from the carburetor air cleaner passes through the crankcase inlet ventilator conduit into the crankcase and sweeps blow-by gases collected therein through the crankcase outlet ventilator conduit and into the inlet manifold. However, during certain operating conditions, such as heavy acceleration or wide open throttle (WOT), the flow in the crankcase inlet ventilator conduit is reversed and blow-by gases from the crankcase flow through the crankcase inlet ventilator conduit to the carburetor air cleaner (hence the term back-up tube) and into the induction system as well as through the outlet ventilator conduit. This flow reversal also occurs during engine start-up.

FIG. 1 shows a closed engine ventilating system and the ventilator flow therethrough, as indicated by the arrows, at light loads such as at idle. Engine 10 includes crankcase 12 and an engine induction system which may consist of a carburetor air cleaner snorkel l4 having a fresh air inlet and passage communicating with carburetor air cleaner 16, a carburetor 18 including an upper induction conduit 20 communicating with air cleaner 16 and a throttle valve 22 and finally an inlet manifold means 24, which communicates with a combustion chamber 26. The system also includes ventilator outlet means which may consist of a crankcase ventilator valve 28 and a first crankcase ventilator conduit 30 which extends between valve 28 and inlet manifold 24 via the carburetor induction conduit. The ventilator inlet means for the system consists of a crankcase inlet means such as crankcase air cleaner 32 which communicates with the engine crankcase. Connectedbetween snorkel l4 and crankcase air cleaner 32 is a second crankcase ventilator conduit or back-up tube 34, which functions at light loads and idle as a ventilator inlet conduit to the crankcase. 7

As indicated hereinabove, and as shown in FIG. 1, at light engine load such as at idle, fresh air flows from the snorkel through back-up conduit 34 into crankcase l2 picking up blow-by vapors and exits through valve 28 and crankcase ventilator conduit 30 to be directed to the combustion chamber via inlet manifold 24. However, at heavy loads such as wide open throttle, starting or heavy acceleration, the direction of flow in back-up conduit 34 reverses and blow-by vapors and other crankcase vapors flow out of both the crankcase ventilator conduit 30 and back-up conduit 34 into the engine induction system.

Heated intake air is supplied to the carburetor by conduit 36 and an arrangement which is best shown in FIG. 2. A sheet metal stove 38 is attached to the exhaust manifold 40. Underhood air entering the stove is heated as it passes over the hot manifold. The heated air is conducted from stove 38 to the carburetor snorkel 14 on air cleaner 16 through a suitable conduit arrangement indicated by 36 and 42. A thermostatically controlled air valve door 44, the thermostat being a standard bimetal type indicated at 46 and arrangedto control the application of manifold vacuum in

conduits

48 and 50 to a vacuum diaphragm actuator 52 which operates door 44, controls the air temperature entering air cleaner 16. With this arrangement air cleaner 16 thermostatically controls the induction air temperature at somexdesired-value, such as 100 7F., through an upper speed limit, such as 70 mph road loadoperation. At higher speeds, decreasing manifold vacuum and increasing differential pressure across the temperature control door valve cause the door to open gradually until a manifold vacuum of say 5.5 inches of Hg is reached. At that time heat control door 44 closes the heated air inlet. Under these conditions, as is true for wide open throttle operation at all speeds, the'induction air temperature is the same as the underhood temperature. The use of a heated air system does not materially increase the induction air temperature during warm weather operation but it does raise the intake temperature in cold weather. The decreased spread in temperature range permits the use of leaner fuel-air mixtures for reduced emissions while maintaining good drivability the year round.

The vacuum operated, bimetal controlled door 44 is best seen in FIGS. 3 and 4, particularly as it is modified by this invention. In FIG. 3, door 44 is shown mounted in the carburetor air inlet snorkel such that it has two fully closed positions 44a and 44b (shown in phantom) at the opposite extremes of its travel about mounting hinge 54. Position 44a is fully closed with respect 'to ambient air inlet 46 at the open end of snorkel 14. Position 44b is fully closed with respect to heated air inlet 58 in the floor of the snorkel body; Of course, there are a plurality of intermediate door positions between the two extremes atwhich the door may be placedby actuator arm 60 which operably connects .door 44 to the vacuum diaphragm actuator means 52 thus providing mixtures of ambient and heated air to the air cleaner.

Back-up tube or conduit 34 is preferably connected to snorkel 14 as shown proximate an edge of door 44 with at least a portion of its opening into snorkel I4 slightly upstream of the door edge when door 44 is canted upward in position 44a, although it may be placed in other positions in the snorkel.

As previously stated, back-up tube 34 dumps fuelrich vapors into snorkel 14 at various times during engine operation. There is some danger that these vapors may escape out open end 56 of snorkel 14. This is particularly true when door 44 is in position 44a. This invention eliminates this problem by providing door 44 with an aperture, such as notch 62, best seen in FIG. 4, whereby a small amount of ambient air leakage is allowed past door 44 thus assuring that the flow of vapors of back-up tube 34 is always inwardly directed toward air cleaner 16. In the relative positions shown, the notch and adjacent back-up tube 34 further assure dilution of these vapors by ambient fresh air and decrease the problem of hot start die-out also. 7

Having described a preferred embodiment of the invention, the embodiments thereof in which an exclusive property right is claimed are as follows:

1. In a thermostatically controlled heated inlet air system for the air induction passage of an internal combustion engine:

a carburetor having air inlet means including an ambient air inlet and a heated air inlet;

an apertured air control door for selectively controlling the flow of ambient and heated air through the inlets;

thermostatically controlled actuator means movably mounting the door in the carburator air inlet means such that the door has two fully closed positions at the opposite extremes of its travel, one each with respect to the ambient air inlet and the heated air inlet respectively, and a plurality of intermediate positions therebetween whereby ambient air, heated air and mixtures thereof may -be admitted to the carburetor air inlet means, and

a back-up tube connected'to the carburetor air inlet means for carrying vapors from the engine crankcase to the carburator air' inlet means,

whereby the aperture in the air control door assures the presence of at least a small amount of ambient air flow through the air inlet means when the door is closed relativeto the ambient air inlet and the engine is running thereby directing vapors from the back-up tube into the carburetor and preventing their escape out the ambient air inlet to the atmosphere.

2. The combination as defined by claim 1 wherein the carburetor air inlet means comprises an air cleaner having a snorkel air inlet passage.

3. The combination defined by claim 2 wherein the ambient air inlet comprises the open endof the snorkel and the heated air inlet comprises an opening in the floor of the snorkel body.

4. The combination defined by claim 3 wherein the air control dooris hinged at one edge thereof to the floor of the snorkel body for pivotal movement upward therefrom to a canted position in which passage of ambient air through the snorkel is substantially blocked. V

5. In a thermostatically controlled heated inlet air system for the air induction passage of an internal combustion engine: a

a carburetor having air inlet means comprising an air cleaner having a snorkel air inlet passage and including an ambient'air inlet comprising the open end of the snorkel and a heated air inlet comprising an opening in the floor of the snorkel body;

a notched air control door for selectively controlling the flow of ambient and heated air through the inlets, the air control door being hinged at one edge thereof to the floor of the snorkel body for pivotal movement upward therefrom to a canted position in which passage of ambient air through the snorkel is substantially blocked;

thermostatically controlled actuator means movably mounting the door in the carburetor air inlet means such that the door has two fully closed positions at the opposite extremes of its travel, one each with respect to -the ambient air inlet and the heated air inlet respectively, and a plurality of intermediate positions therebetween whereby ambientair, heated air and mixtures thereof may be admitted to the carburetor air inlet means, and

a back-up tube connected to the carburetor air inlet means for carrying vapors from the engine crankcase to the carburetor air inlet means,

the back-up tube being positioned on a side of the snorkel body with at least a portion thereof slightly upstream of the door edge when his in the canted position and the notch of the door is positioned at the edge thereof most proximate to 5 the back-up tubes point of attachment to the snorkel body.

Claims

1. In a thermostatically controlled heated inlet air system for the air induction passage of an internal combustion engine: a carburetor having air inlet means including an ambient air inlet and a heated air inlet; an apertured air control door for selectively controlling the flow of ambient and heated air through the inlets; thermostatically controlled actuator means movably mounting the door in the carburator air inlet means such that the door has two fully closed positions at the opposite extremes of its travel, one each with respect to the ambient air inlet and the heated air inlet respectively, and a plurality of intermediate positions therebetween whereby ambient air, heated air and mixtures thereof may be admitted to the carburetor air inlet means, and a back-up tube connected to the carburetor air inlet means for carrying vapors from the engine crankcase to the carburator air inlet means, whereby the aperture in the air coNtrol door assures the presence of at least a small amount of ambient air flow through the air inlet means when the door is closed relative to the ambient air inlet and the engine is running thereby directing vapors from the back-up tube into the carburetor and preventing their escape out the ambient air inlet to the atmosphere.

3. The combination defined by claim 2 wherein the ambient air inlet comprises the open end of the snorkel and the heated air inlet comprises an opening in the floor of the snorkel body.

4. The combination defined by claim 3 wherein the air control door is hinged at one edge thereof to the floor of the snorkel body for pivotal movement upward therefrom to a canted position in which passage of ambient air through the snorkel is substantially blocked.

5. In a thermostatically controlled heated inlet air system for the air induction passage of an internal combustion engine: a carburetor having air inlet means comprising an air cleaner having a snorkel air inlet passage and including an ambient air inlet comprising the open end of the snorkel and a heated air inlet comprising an opening in the floor of the snorkel body; a notched air control door for selectively controlling the flow of ambient and heated air through the inlets, the air control door being hinged at one edge thereof to the floor of the snorkel body for pivotal movement upward therefrom to a canted position in which passage of ambient air through the snorkel is substantially blocked; thermostatically controlled actuator means movably mounting the door in the carburetor air inlet means such that the door has two fully closed positions at the opposite extremes of its travel, one each with respect to the ambient air inlet and the heated air inlet respectively, and a plurality of intermediate positions therebetween whereby ambient air, heated air and mixtures thereof may be admitted to the carburetor air inlet means, and a back-up tube connected to the carburetor air inlet means for carrying vapors from the engine crankcase to the carburetor air inlet means, the back-up tube being positioned on a side of the snorkel body with at least a portion thereof slightly upstream of the door edge when it is in the canted position and the notch of the door is positioned at the edge thereof most proximate to the back-up tube''s point of attachment to the snorkel body.