US2829629A

US2829629A - Ventilating system for an internal combustion engine

Info

Publication number: US2829629A
Application number: US623111A
Authority: US
Inventors: Dana K Badertscher; Milton S Bald
Original assignee: American Motors Corp
Current assignee: American Motors Corp
Priority date: 1956-11-19
Filing date: 1956-11-19
Publication date: 1958-04-08
Anticipated expiration: 1975-04-08

Description

D. K. BADERTSCHER ET AL 2,

VENTILATING SYSTEM FOR AN INTERNAL COMBUSTION ENGINE A ril s, 1958 Filed Nov. 19, 1956 m. n m

M/crmv 5. 80L 2 BY i I atent Ofiice 2,829,629 Patented Apr, 8, 1958 VENTILATHQG SYSTEM FOR AN INTERNAL COMBUSTION ENGINE Application November 19, 1956, Serial No. 623,111 8Claims. (Cl. 123-419) The invention relates to a ventilating system for removal of harmful and corrosive vapors from the crankcase of an internal combustion engine and particularly of the type suitable for operation while submerged ternporarily under water.

In an engine of the type suitable for under water operation, the various components such as the distributor, spark plugs, fuel pump, etc., are fabricated in such a way as to be housed in water-tight receptacles and most of these components need air for some reason and consequently, must be provided with a ventilating system.

The general object of the invention is to provide an improved air route arrangement in a ventilating system for an internal combustion engine.

A specific object is to provide an improved valving arrangement in an engine ventilating system wherein a combination valve is housed in a single casting and operated with a single control element.

A further object is to provide a relief valve with appropriate passageways circumventing the main control valve for relieving excessive crankcase back pressure when necessary to avoid possible fracture of sealing gaskets where provided.

Other objects and advantages will be apparent from the ensuing specification and appended drawing in which:

Figure 1 is a schematic view of an engine employing the ventilating system;

Figure 2 is a plan view of the combination control valve taken generally on the line 2-2 of Figure 1;

Figure 3 is a fragmentary sectional view taken on the line 3-3 of Figure 2;

Figure 4 is a fragmentary sectional view taken on the line 44 of Figure 2; and

Figure 5 is a detail sectional View of the crankcase ventilation control valve.

Referring to Figure l, we have shown schematically a typical V-type internal combustion engine having a crankcase A to theunderside of which is secured the oil storage pan B. The cylinder castings C and D happen to be of the removable type secured to the crankcase casting with suitable sealing means. The cylinder castings, of course, house the conventional pistons (not shown) which are actuated by the conventional crankshaft (not shown) mounted within the crankcase casting in a conventional manner. In this particular engine overhead type valves (not shown) are employed and these are housed within the cylinder heads C and D covered by covers E and F, the combustion chambers being also located within the cylinder heads. The combustion chambers are fed through the intake manifold ducts G and H which emanate from the intake manifold I. A conventional carburetor (not shown) would be positioned between the intake manifold and the air cleaner I for atomizing the fuel before entering the intake manifold preparatory to distribution to the various cylinders.

In an engine which is not intended for underwater operation, the distributor and fuel pump would incorporate small vent holes, however, the instant engine employs in its ignition system a distributor K and a fuel pump L, both of which are provided with appropriate means for accepting the tubing so as to be included in the air route of the ventilating system.

The ventilating system is preferably accomplished in part by the use of sections of tubing extending between the various parts which need venting and it will be understood that the tubing as shown in Figure 1 is greatly oversized in proportion to the engine size as shown and it will be understood that the actual size of the tubing sections need only be such as to provide the desired venting as needed. The system may be said to commence at the air cleaner with tubing sections 10 and 11 leading from a common fitting 12 which is in open communication with filtered air of the air cleaner. The section It) terminates at the distributor K and section 13 leaves the distributor and leads to the inlet passage 14 in the combination valve assembly which may be identified generally with the letter M. The passage 14, with the valve core 15 in. its normally opened position as shown in Figures 3 and 4, communicates with outlet passage 16 into tubing section 17 which leadsinto the intake manifold, first passing through the valve assembly which may be generally identified with the letter N.

Section 11 leads from the air cleaner into passage 18 (see Figure 3) of the combination valve assembly and, with the valve core in open position, communicates with passage 19 which opens into the interior of the crankcase. The valve body which may be identified by the numeral 20 has an externally threaded fitting portion 21 which is threaded into the boss 22 which is formed on the timing gear cover which communicates with the crankcase.

From the crankcase casting a section of tubing 23 leads to the interior of the cylinder head cover F from whence the discharge passage 24 opens into the tubing section 13. it will be understood that there is a tubing section 23 to accommodate each bank of cylinders, the tubing section leading to the cylinder head cover E not being shown. A section of tubing 25 leads from the discharge passage 26 of the cylinder head cover E to the inlet passage 27 in the combination valve body, said latter passage intersecting with the passage 14 previously referred to. A section of tubing 28 leads from valve passage 29 to the fuel pump L which represents a dead end for this particular tubing section. It is not necessary to maintain a continuous run in the air route through the fuel pump. This is due to the fact that there are only air pulsations caused by the stroke of the fuel pump diaphragm.

Viewing Figure 2, it will be noted that the passages in the valve body as shown in Figure 3 lie in a plane which is spaced from the plane in which the passages as shown in Figure 4 lie. The valve body has a valve seat in the form of a conical bore 30 extending therethrough which bore intersects the

transfer passages

31 and 32 and the valve core 15 has diametn'c bores 33 and 34 which are in registry with the

respective transfer passages

31 and 32 at a common position of the valve core within the bore. Thus, when the valve core is rotated to open position, both of the core bores 33 and 34 are in registry with the respective transfer passages simultaneously and likewise when the valve core is rotated to closed position, the

transfer passages

31 and 32 are closed oif simultaneously.

In Figure 2, there is shown a preferred form of valve control consisting of a Bowden wire 35 operable within a suitable sheathing 36 which may be supported near the control knob 37 by means of any suitable stationary support 38. The end of the sheathing adjacent the valve assembly is anchored within the loop 39 formed at the end of the arm 41a which may be integral with the bracket 41. The bracket is secured to the end face of the valve body as by means of bolts 42 and a pair of outwardly turned ears 43 and 44 on the bracket serve as stops when rotating the valve core to open or closed position. The valve core has a diametrically reduced end portion 45- projecting exteriorly of the valve body and one end of link 46 is secured to the end of the valve core. A pin 47 is carried on the opposite end of the link rotatively relative thereto, the end of the Bowden wire being anchored to the pin as by means of set screw 48. The bracket has an extension 49 with an outwardly turned ear t and the opposite ends of tension spring 51 are anchored respectively to the link 46 and the car 50 for assisting in returning the valve core to open position (with the link engaging. ear 44). Thus when it is desired to close the valve, the knob 37 is pulled outwardly causing the link to swing over against car 43 (the position shown in Figure 2). valve core a spring 73 exerts tension on the pin 74 to retain the valve core (which is of the tapered or conical type to conform to the valve seat) in the valve body.

Operation In operation, assuming that the engine is functioning under normal conditions without being submerged, then the valve core is in its normally open position as shown in Figures 3 and 4 wherein link 46 is engaged with ear 44 and the overall air route from the air cleaner to the intake manifold is open as a result of the

transfer passages

31 and 32 being open. Then the atmospheric air travels through the air cleaner as indicated by the arrow 4t and thence through the tubingsections 1t and 11. The air flow is induced as a result of the suction condition (or subatrnospheric pressure condition) Within the intake manifold and the air travels through tubing 11, passage 18, transfer passage 31, valve core bore 33,

outlet passage 19 into the interior of the crankcase where the accumulation of blow-by gases is picked up and discharged as desired through the tubing sections 23 into the interiors of the respective cylinder head covers E and F, then through

discharge passages

24 and 26 into

tubing sections

13 and 25, then through passages 27 and 14, transfer passage 32, valve core bore 34, passage 16, into tubing 17 and on into the intake manifold through the regulating valve N. The air which flows through tubing it travels through the interior of the distributor casing and on through tubing 13 where it merges with the air being expelled out of discharge passage 24. The air traveling through tubing 11 and valve passage 18 is exposed to the passage 29 which leads through tubing 28 into the fuel pump L, the passage 28 being a dead end one.

During periods in which a high vacuum condition exists within the intake manifold, such as would tend to induce a high. volume flow so as to interfere with the proper operation of the carburetor, it is necessary to restrict air flow through tubing 17 and this is accomplished by means of the regulating valve N which is conventional. The tubing 17 leads into the valve fitting 61 and the tubing section 62 is connected at the discharge end 63 of the valve which leads into the intake manifold. Under normal operating conditions, the spring 64 urges the valve element 65 to the position as shown in Figure 5 wherein the air flow through the valve element includes a path leading through the side openings 66 and thence around the exterior of the valve element through the annular passage 67 and on through passage 68 into tubing. 62. A portion of such air would also travel through the bleed opening 69. Under high vacuum conditions such as are prevalent during idling of the engine the valve element moves to the right (viewing Figure 5) against the tension of the spring and the conical end face 69 of the valve closes against the valve seat 61 causing the air flow to be confined to passing through the bleed" opening 69. It will be understood that the At the opposite end of the regulating valve N, of course, responds automatically to the vacuum condition within the intake manifold.

When the engine is submerged under water, the overall air route of the ventilating system is closed ofi by rotating valve core 15 until link 4-6 is engaged with car 43 wherein the valve bores 33 and 34 are moved out of registry with the

transfer passages

31 and 32. With these transfer passages closed off, the passage 16 leading to the intakemanifold is closed off and there is no air flow through the system. The crankcase and passage 19 is likewise closed olf from passages 18 and 29 (subject to the activity of valve 52). This condition is only temporary since it is not intended that the engine should operate under water for any extensive period of time. During the operation of the engine with the valve core 15 closed, a pressure condition builds up within the crankcase, suflicient to counteract the pressure of the water in which the engine is submerged and thereby preventing entry of water into the interior of the engine. To prevent excessive pressure build up in the crankcase (such as might fracture the various sealing gaskets), a relief valve indicated generally by the numeral 52 is provided and this valve may be in the form of a ball check valve wherein the ball 53 is normally seated at the end of passage 54 under the tension of spring 55. With transfer passage 31 closed off by valve core 15, whenever excessive pressure builds up in the crankcase, the ball 53 will be unseated to relieve the excessive pressure and the air can flow through passage 54- and passage 56 and thence out through tubing section 11 to the air cleaner 1. The passages 54 and 5'6 thus circumvent the transfer passage 31. The outer end of passage 56 may be closed off with a threaded plug 57 and a similar threaded plug 58 closes oil the enlarged outer end of passage 54, the diametrically reduced inner end of the plug serving as a pilot and shoulder for the spring and also serving to limit the travel of the ball 53. It will be understood that during operation of the engine under Water, the intake at which the atmospheric air enters the breathing system (herein shown as being the air cleaner 1) is always kept above-the water level.

We have shown our invention as used with a V-type, 4 cylinder engine and it will be understood that in the case of a flat or so-called opposed type of engine the scavenging of the gases can be via a direct route leading from the crankcase to the valve M. The reason for this is that in order to prevent the precision components of the engine from becoming etched by corrosive vapors, it is desirable to vent from the highest point in the engine and in a flat type engine a vent from the highest point of the crankcase would be sufficient. Thus any corrosive vapors in the cylinder head covers could be drawn off through suitable passages formed in the engine block leading to the crankcase or (as in the case of an engine employing the type of cylinder castings shown herein) through suitable tubes (comparable to tubes 23) leading from the cylinder head covers to the crankcase.

We claim:

1. In a breathing system for an internal combustion engine having an air cleaner, a cylinder head cover, a crankcase, an intake manifold, and a control valve, an air route for interconnecting the aforementioned engine parts comprising: a duct leading from the air cleaner to the control valve; a second duct leading from the air cleaner to the valve and being in open communication with the first duct; a duct establishing communication between the crankcase and the second air cleaner-to-valve duct via the head cover; an additional duct establishing communication between the intake manifold and the valve, said valve being operable to temporarily close off the air route.

2. In a breathing system for an internal combustion engine having a cylinder head cover, a crankcase and an intake manifold: 21 valve body having several pasasaaseo sages therethrough; a first passage in the valve body establishing communication between the interior of the crankcase and atmosphere; an air duct establishing communication between the interior of the crankcase and the cylinder head cover; an additional air duct establishing communication between the cylinder head cover and the valve body; a further duct establishing communication between the valve body and the intake manifold; 21 second passage in the valve body for establishing communication between the last two mentioned ducts and a common valve for closing oil the first and second valve body passages.

3. In a breathing system for an engine having a crankcase and an intake manifold, an air route for establishing communication between the aforementioned engine parts and including: a branch establishing communication between the interior of the crankcase and atmosphere; an additional branch establishing communication between the interior of the crankcase and the intake manifold; a common valve interposed in the branches and operable to close off both branches.

4. In a breathing system for an engine having a crankcase and an intake manifold, an air route for establishing communication between the aforementioned engine parts and including: a branch establishing communication between the interior of the crankcase and atmosphere; an additional branch establishing communication between the interior of the crankcase and the intake manifold; a valve body having one passage therethrough serving one branch and another passage therethrough serving the additional branch; a valve in the valve body operable to simultaneously close off the passages in the valve body.

5. In a breathing system for an engine having a crankcase and an intake manifold, an air route for establishing communication between the aforementioned engine parts and including: a branch establishing communication between the interior of the crankcase and atmosphere; an additional branch establishing communication between the interior of the crankcase and the intake manifold; valve means for closing off the branches; additional valve means responsive to pressure for opening: and bleeding oif excess air within one of the branches.

6. In a breathing system for an engine .as set forth in claim 2 wherein the valve body has a third passage therein for circumventing the common valve to establish communication between opposite ends of one of the first mentioned valve body passages and a pressure responsive normally closed valve operable to open the third passage.

7. In a breathing system for an engine having a cylinder head, a crankcase and an intake manifold, an air route for establishing communication between the aforementioned engine parts and including: a branch establishing communication between the interior of the crankcase and atmosphere; an additional branch establishing communication between the interior of the crankcase and the intake manifold via the cylinder head cover; a valve body having one passage therethrough serving onebranch and another passage therethrough serving the additional branch; said valve body having a bore therethrough which intersects both of the valve body passages; a valve rotatably received in the bore.

8. In a breathing system for an engine having a crankcase and an intake manifold, an air route for establishing communication between the aforementioned engine parts and including; a branch establishing communication between the interior of the crankcase and atmosphere; an additional branch establishing communication between the interior of the crankcase and the intake manifold; a valve in each branch and means for simultaneously closing the valves.

No references cited.