US2659353A

US2659353A - Ignition timing control means for internal-combustion engines

Info

Publication number: US2659353A
Application number: US237037A
Authority: US
Inventors: Mallory Marion
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-07-16
Filing date: 1951-07-16
Publication date: 1953-11-17
Anticipated expiration: 1970-11-17

Description

Nov. 17, 1953 M. MALLORY 2,659,353

IGNITION TIMING CONTROL MEANS FOR INTERNAL-COMBUSTION ENGINES Filed July 16, 1951 /3 j 4 c I ADVANCE R 7 4 9 b 2 a 3 7 M v, a a m U m N m In 0 E 3 3 ENGINE R.P.M.

Fig. 2.

INVENTOR. Mar/on Mal/om ATTORNEYS.

Patented Nov. 17, 1953 OFFICE IGNITION TIMING CONTROL MEANS FOR INTERNAL-COMBUSTION ENGINES Marion Mallory, Detroit, Mich. Application July 16, 1951, Serial No. 237,037

11 Claims.

This invention relates to ignition timing control means for internal combustion engines.

This invention is an improvement on the pressure ignition systems shown in my Patent 2,268,490 and in my copending application Serial No. 207,369, filed January 23, 1951, and is concerned with an ignition timing control means which uses the manifold vacuum for both part and full throttle spark control.

In the present day pressure ignition systems, such as shown in my patent and the above application, the servo-motor which advances and retard the spark is connected into the intake passageway through an orifice positioned just above or on the atmosphere side ofthe throttle valve when in idle position and this orifice passes on to the engine side of the throttle valve as soon as it is opened from idle position. With this type of pressure ignition when the throttle valve is positioned slightly above the said on'fice, then the orifice is subjected to (1) the static manifold vacuum and (2) the velocity vacuum, that is, the vacuum induced by the velocity flow of fluid by the throttle and orifice. The combination of the static manifold vacuum and the velocity vacuum produces a combined vacuum which is higher than the manifold vacuum. This is undesirable because it produces too much spark advance and detonation at part throttle. This undesirable situation for part throttle spark advance can be solved by tightening or strengthening the spring which resists spark advance but this solution is not satisfactory because under such conditions when the throttle is wide open and the vacuum low, the velocity vacuum will not be able to overcome such a strong spring and not enough spark advance will be obtained for wide open throttle operation. J

It is the object of this inventionto solve the above problem and remedy the above specified undesirable condition and this is efiected by bleeding down the combined velocity and static manifold vacuum at part throttle operation to thereby eliminate the overage in vacuum due to the combining of the velocity'and static manifold vacuums and thereby bring the vacuum spark advance for part throttle operation back within its proper range. 1

In the drawing: i

Fig. 1 is a sectional-view partly in elevation showing the mechanism of my ignition contro means for internal combustion engine.

' In Fig. 2' the curve A shows the Venturi' suction at wide open throttle and the desired ignition or spark timing advance for the correspond- 3l is anchored at one end as at ing speed and curve B shows the manifold suc tion at part throttle in my pressure ignition system which is communicated to the servo-motor for advancing or retarding the spark and the desired spark timing advance for the corresponding speed which is obtained by my present ignition system.

Fig. 3 is a detail sectional view showing a modified form of my invention.

The part illustrated in Fig. 1 of the drawings are as follows: carburetor I, venturi 2, air inlet 3 into the carburetor passageway, fuel mixture outlet 4 into the intake manifold, float bowl 5, fuel nozzle 6, throttle valve 1 of the butterfly type (throttle valve 1 is preferably manually actuated by conventional means not shown), shaft 8 journalled in carburetor housing I and supporting butterfly valve 1, orifice l positioned above on the atmosphere side of, and adjacent, throttle valve 1 when in idle position, pipe line H connecting orifice In with suction device generally designated I 2.

The timing mechanism consists of the usual rotatable cam l4 which rotates in the direction indicated by the arrow. I Cam 14 operates a conventional circuit breaker I5 (arm 34 pivoted on plate l6 at 35, rubbing block 36, contacts 31 and 38 mounted respectively on arm 34 and plate I6) mounted on plate |6-which can be rotated counterclockwise to advance the spark and clockwise to retard the spark, as indicated. Suction device l2 is utilized for advancing and retarding the spark. I

Suction device l2 comprises a flexible diaphragm l1. Diaphragm I1 is mounted in housing I9. Diaphragm I l divides housing I 9 into chamber which communicates with atmosphere and into suction chamber 2| "which is'in' communication with line H. Diaphragm I! is connected to plate It by rod 22, one end of which :is pivotally connected the other end of which is fixed to the diaphragm.

to plate l6-as at 23 and The ignition distributor housing is designated 24. A tension coil spring 25 has one end anchored to post 26 fixedon plate l6 and the other end anchored to post 21 fixed on housing 24. Pin 28, fixed to stationary housing 24, extends into arcuate slot 29 in' plate [6 and limits the rotation or oscillation of plate It to any number of degrees, preferably through an arc of about 40. Post 30 is fixed on plate [6' and leaf spring 32 to a bracket 33 fixed to, and within, housing 24. The free end of leaf spring 3| extends into the path of post A second orifice 9 communicates with tube or pipe line H by branch line I3. Orifice 9 is positioned in the intake passageway or carburetor housing preferably adjacent to a plane (indicated by the line C) perpendicular to the longitudinal axis of the carburetor or intake passageway and passing through the uppermost tip 49 of the carburetor when in wide open position and, in any event, between this plane C and orifice III which is just above the throttle when in idle position. In any event, orifice 9 should be positioned adjacent orifice so that it serves to bleed down the combined manifold and velocity vacuum obtaining at orifice H) as long as the throttle is in partly open position and particularly when the throttle is open less than about half way between idle andwide open throttle positions.

If the spark advance required for wide open throttle is, say, for example, 15, then this suction in-chamber 2| will act through diaphragm l1 and rod 22 to move plate It and circuit breaker I counterclockwise the required in an advance spark direction. Weak spring 25 will yieldably resist this counterclockwise rotation of plate It to advance the spark. Since the Venturi suction at wide open throttle, e. g., reaches about three inches of mercury, as indicated in Fig. 2, it is necessary that spring 25 be a weak spring so that the spark will start to advance at around 500 R. P. M. engine speed when the vacuum is low.

In the above ignition timing system I accomplish ignition timing by opposing rotation of plate. It in a spark advance direction with a strong force (for example, the combined resistance or force of springs 3|, 25) when the suction in chamber 2| is above maximum venturi or intake passageway suction (curve A),

and I use a weak force, that is, a weak spring 25 for opposing the venturi or intake passageway suction when it alone is acting upon suction device I! to advance the spark. Spring ll, of course, does not act against post 39 and plate l6 unless the suctionin chamber 2| is higher than the maximum Venturi or intake passageway suction, curve A. In other words, in my ignition timer I use a weak spring for the low vacuums which exist in the suction device when the engine is operating at wide open throttle thereby making the wide open throttle spark'curve starting from low speed to high speed with the weak spring 25. The stiff spring is the limit of the spark advance any time-the throttle is wide open regardless of the engine speed. When the vacuums in the suction device are very hi h under part-throttle operation, then the stiff or strong spring 8| opposes these vacuums in advancin the spark. The stiff spring 3| acts as a stop for the advance when the throttle is wide open and the engine running at high speeds. The low vacuum existing in suction device 2| when the engine is running at wide open throttle will not advance the plate It against stifi spring 3| 4 throttle I is opened wide, then the spark advance falls back to curve A, Fig. 2.

In the form shown in Fig. 3, instead of two separate orifices 9 and III a single orifice 4| is used. This orifice in effect consists of widening orifice 9 until it merges with orifice H) and the enlarged orifice 4| functions the same as orifices 9 and Hi. When the throttle is opened slightly above idle position, dotted line showing Fig. 3, then the static intake manifold vacuum and the velocity vacuum are imposed upon the portion of enlarged orifice 4| below, or on the outlet side 4 of, throttle valve 9 but this combined vacuum is bled down from atmosphere through the portion of orifice 4| above throttle valve 9 so that the spark is again advanced and retarded in accordance with curve B, Fig. 2. Here again orifice 4| should extend from a point slightly above the throttle valve I when closed for idle to a point within the plane C, referred to above and shown in Fig. 1.

I claim:

1. In an internal combustion engine the combination of an ignition timer operatable through a given range measured in degrees to advance and retard the ignition spark, a fuel mixture intake passageway, a manually controlled throttle valve for said intake passageway, a suction device responsive to intake passageway pressure f r v ncin and retarding said ignition timer, a conduit connecting said fuel mixture intake passageway with said suction device, said conduit communicating with said intake passageway adjacent to, and on the atmosphere side of. said throttle valve when the throttle valve is closed in idle position and communicating with said intake passageway simultaneously on both the inlet and outlet sides of said manually controlled throttle valve when the valve is partly open, the area of communication between said conduit and intake passageway being always located between the valve when closed for idle and a plane passing through the upstream tip of the throttle valve and perpendicular to the plane of the throttle valve when wide open and being located entirely on the outlet side of the throttle valve when the throttle valve is open to a position greater than substantially half way between idle. and fully opened positions.

2. The combination defined in claim 1 wherein said throttle valve is a butterfly valve.

3. The combination defined in claim 2 wherein the communication between the conduit and the intake passageway is in the form of a single opening.

4. The combination defined in claim 2 wherein the communication between said conduit and intake passageway is in the form of two openings, one of which is positioned adjacent the throttle valve when closed for idle and the other of which is positioned above and between said first orifice and a plane passing through the upstream tip of the throttle valve when wide open.

5. In an internal combustion engine the combination of an ignition timer operatable through a given range measured in degrees to advance and retard the ignition spark, a fuel mixture intake passageway, a throttle valve for said intake passageway. a suction device responsive to intake passageway pressure for advancing and retarding said ignition timer, a conduit connecting said fuel mixture intake passageway with said suction device, said conduit communicating with said intake. passageway adJacent to, and onthe atmosphere side of, said throttle valve when the throttle valve is closed in idle position and communicating with said intake passageway on both the inlet and outlet sides of said throttle valve when the valve is partly open, the area, of communication between said conduit and intake passageway being always located between the valve when closed for idle and a plane passing through the upstream tip of the throttle valve and perpendicular to the plane of the throttle valve when wide open, and resilient means yieldably opposing operation of the timer to advance the spark through a predetermined number of degrees and yieldably opposing further advance of the ignition timer with a greater force throughout the remaining range of adjustment of the timer to further advance the spark.

6. The combination claimed in claim 5 wherein said resilient means comprises two independent springs.

7. The combination claimed in claim 6 wherein the one spring opposes operation of the timer to advance the spark throughout its entire range and the second spring is stronger than the first spring and opposes operation of the timer to advance the spark only when the suction device is subjected to a suction greater than the maximum suction obtaining at said orifice at wide open throttle.

8. In an internal combustion engine the com bination of an ignition timer operatable through a given range measured in degrees to advance and retard the ignition spark, a fuel mixture intake passageway, a throttle valve for said intake passageway, a suction device responsive to intake passageway pressure for advancing and retarding said ignition timer, a conduit connecting said fuel mixture intake passageway with said suction device, said conduit communicating with said intake passageway adjacent to, and on the atmosphere side of, said throttle valve when the throttle valve is closed in idle position and communicating with said intake passageway on both the inlet and outlet sides of said throttle valve when the valve is partly open, the area of communication between said conduit and intake passageway being always located between the valve when closed for idle and a plane passing through the upstream tip of the throttle valve and perpendicular to the plane of the throttle valve when wide open, and a weak spring opposing said pressure actuated means when the pressure actuated means is responding to wide open throttle suction and tending to advance the spark and a relatively stronger spring opposing said pressure actuating means when the pressure actuated means is responding to part open throttle suction and tending to advance the spark.

9. An ignition timer for an internal combustion engine having an intake passageway and a manually controlled throttle valve positioned in said intake passageway, a rotary cam, a support angularly adjustable about said cam, a circuit 7 breaker mounted on said support and arranged to be opened and closed by rotation of said cam, means connected to said support for adjusting the same angularly about said cam to advance or retard the spark, said means comprising a suction device, a conduit connecting said fuel mixture intake passageway with said suction device, said conduit communicating with said intake passageway adjacent to, and on the atmosphere side of, said manually controlled throttle valve when the throttle valve is closed in idle position and communicating with said intake passageway simultaneously on both the inlet and outlet sides of said throttle valve when the valve is partly open, the area, of communication between said conduit and intake passageway being always located between the valve when closed for idle and a plane passing through the upstream tip of the throttle valve and perpendicular to the plane of the throttle valve when wide open and being located entirely on the outlet side of the throttle valve when the throttle valve is open to a position greater than substantially half way between idle and fully opened positions.

10. An ignition timer for an internal combustion engine having an intake passageway and a throttle valve positioned in said intake passageway, a rotary cam, a support angularly adjustable about said cam, a circuit breaker mounted on said support and arranged to be opened and closed by rotation of said cam, means connected to said support for adjusting the same angularly about said cam to advance or retard the spark, said means comprising a suction device, a conduit connecting said fuel mixture intake passageway with said suction device, said conduit communicating with said intake passageway adjacent to, and on the atmosphere side of, said throttle valve when the throttle valve is closed in idle position and communicating with said intake passageway on both the inlet and outlet sides of said throttle valve when the valve is partly open, the area of communication between said conduit and intake passageway being always ioeated between the valve when closed for idle and a plane passing through the upstream tip of the throttle valve and perpendicular to the plane of the throttle valve when wide open, and resilient means yieldably opposing angular movement of said support in a spark advancing direction when the suction applied on the suction device through said orifice and conduit is that obtaining at said orifice at substantially wide open throttle operation and a relatively stronger resilient means for yieldably opposing such movement of the support when the suction applied on the suction device is that obtaining at said orifice at part open throttle operation.

11. The combination set forth in claim 1 wherein the communication between the conduit and the intake passageway is in the form of two openings, one of said openings being located closely adjacent and upstream from the valve when in closed idle position, the other opening being located closely adjacent and downstream of a plane passing through the upstream tip of the valve when in fully opened position and perpendicular to the plane of the valve when in fully opened position.

MARION MALLORY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,388,628 Berdon Aug. 23, 1921 2,039,396 Darnell et al May 5, 1936 2,066,640 Melcher et al. Jan. 5, 1937 2,134,354 Boyce Oct. 25, 1938