US2503753A

US2503753A - Ignition timing control means for internal-combustion engines

Info

Publication number: US2503753A
Application number: US793093A
Authority: US
Inventors: Mallory Marion
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-12-22
Filing date: 1947-12-22
Publication date: 1950-04-11
Anticipated expiration: 1967-04-11

Description

Aprll 11, 1950 MALLQRY 2,503,753

IGNITION TIMING CONTROL MEANS FOR v INTERNAL- COMBUSTION ENGINES Filed D90. 22, 1947 RETARD 600 I000 I400 I800 2200 SPEED REM.

INVENTOR. L Y [E- 2 MAR/ 0N MALLOI? ATTORNEYS.

Patented Apr. 11, 1950 OFFICE IGNITION TIBHNGCONTROL MEAN S FDR INTERNAL-:COMBUSTION ENGINES Marion lvlallcry, Detroit, Mich. Application December v22, 1941, Serial No. :93.093

l This invention relates to ignition timing con: trol means for an internal combustion engine. This invention contemplates an ignition system which is controlled by thepressures obtain ing in the intake passageway of the engine so that the spark will beretarded when the engine is idling, will advance in direct relation to the engine speed when thethrottle is wide open. and will advance ahead of the load curve at inter mediate positions of the throttle.

' Fig. 1 is a sectional view showing the ,m'echa nism of my ignition timing control means for an internal combustion engine.

, Fig. 2 is a graph showing one curve for the part throttle spark advance and another curve for the full throttle spark advance.

Referring more particularly to the drawings there is shown a carburetor 1 having an atmospheric air inlet 2, an outlet .3 to the engineintake manifold, a throttle valve 4 of the butterfly type mounted on the usual shaft 5 iournalled in the carburetor housing, a venturi 6 having an orifice I, Another orifice .8 is located in the intake pas sageway adjacent to, but on the atmosphereside of, throttle valve dwhen in idle position.

The timing mechanism is conventional and, as. shown, consists of the usual rotatable cam I9 which operates the electrical circuit breaker Iii. The circuit breaker ill is mounted onplate ll. which .can be rotated clockwise to advance the spark and counterclockwise to retard the spark.

Two suction devices are utilized for advancing.

and retarding the spark. One suction device 12 comprises a flexible diaphragm is backed up by compression spring I 4. Diaphragm 13 is mounted in housing I5, the suction chamber 16 0i which is connected by conduit ll with orifice l. phra m I3 is connected to plate I I by connecting rod I8, one end of which is pivotally connected to plate II as at 19 and the other end of which is fixed to the diaphragm.

The other suction device, for purposes of illustration, is shown as comprising cylinder 20, piston 2|, compression spring '22 which urges piston 2| toward the right, and conduit 23 which connects cylinder with orifice ,8. A connecting rod-24 has a fixed pivotal connection as at 25 with piston 2| and has a lost motion connectionwith plate II in the .form of pin 26 on plate I l which interengages connecting rod 24 in elongate slot 27.

The operation of my device is as follows: When the throttle valve 4 is wide open the spark advance is in direct relation to the engine speed and this spark advance is illustrated by curve A in Fig. 2. The spark advance at idle engine speed Dia-.

2 andpart throttle is illustrated by curve B, Fig. "2'.

InFig. 1 I have shown the throttle at idle position and the spark is retarded because the pressure at orifices "I and 8 will 'be substantially atmospheric and the pressure in suction chamber it and. within cylinder'fl fl will also be atmospheric at such throttle position.

When throttle 4 is wide open the venturi sue tion created at orifice "l by the velocity of the air flowing through venturi 6 will establish itself in suction chamber [5 and advance the spark in direct relation to the engine speed, as illustrated by curve A. It should be noted that as plate II is rotated clockwise by suction device I2 to advance the spark that this advance is not resisted by spring-22 because pin 26 simply moves freely or idles in elongate slot 2*! and when the spark is fully advanced pin 26 will be short of the left hand end of slot 21.

If the throttle is moved from idle position toward open position, orifice 8 will be placed upon the engine side of the throttle valve and the full manifold vacuum will be applied through orifice 8, conduit 23 upon piston 2i, thereby drawing the same toward the left against the pressure of spring 22. As piston 2'! is drawn toward the left, link '24 contacts pin '26 and controls the spark advance, per curve 'B, Fig. 2. It should be noted that the advance of the spark is very abrupt as orifice 3 passes on to the engine side of valve -4 because the full manifold vacuum will be established in piston 2i Spring 22 is a strong spring but thevacuum is so high when throttle 4 is only partly open that the spark will advance far ahead of the load curve (that is, the curve which exemplifies the degree of opening of throttle valve 4). However, due to the fact that the spring '22 is a relatively strong spring, the spark will immediately retard if the throttle 4 is opened very far toward open position, but never further than permitted by venturi suction at orifice '7 acting through suction device I2.

I claim: p

1. In an internal combustion engine having an intake passageway with a venturi and a throttle valve positioned on the engine side of said vene turi for controlling fluid flow through said passageway, an ignition timer, a'su'ction' device connected into the venturi, a connection between the aforesaid suction device and ignition timer, a second suction device connected into the intake passageway adjacent ,to and on the atmosphere side of the throttle valve when in idle position, a connection between said second suction device and the ignition timer whereby when the throttle valve is wide open the first mentioned suction device responds to venturi suction and controls the position of said ignition timer and when the throttle is partly open the second suction device responds to the suction on the engine side of the throttle valve and controls the position of said ignition timer, the said connection between the second suction device and the ignition timer being a lost motion connection whereby when the throttle valve is wide open the first suction device can actuate said ignition timer independently of said second suction device.

2. In an internal combustion engine having an intake passageway, a throttle valve in the intake passageway, a venturi in the intake passageway on the atmosphere side of the throttle'valve, an orifice in the venturi, a second orifice in the intake passageway adjacent to and on the venturi side of said throttle valve when in idle position whereby the throttle valve moves between the two orifices as it moves toward an open position from idle thereby subjecting the second orifice to the suction obtaining on the engine side of the throttle valve, a suction responsive device connected into the first orifice and a second suction responsive device connected into the second orifice, an ignition timer, connections between. each of the suction responsive devices and the ignition timer whereby when the throttle valve is wide open the first suction responsive device responds to venturi suction and controls the ignition spark advance substantially in direct relation to the engine speed and when the throttle valve is partly open the second suction device responds to the suction on the engine side of the throttle valve and controls the ignition spark advance in accordance with said last mentioned suction, resilient means for moving the ignition timer to retard the spark whenever the suction falls in the first suction device, the connection between the second suction device and the ignition timer being a lost motion connection so that the second suction device positively moves said ignition timer to advancethe spark in response to an increase in suction and is inefiective to move the ignition timer to retard the spark.

3. The combination as set forth in claim 2 wherein the connection between the second suction device and the ignition timer takes the form of a pin and elongate slot. 4. In an internal combustion engine having an intake passageway provided with a throttle valve for controlling the fiow of motive fluid to the engine, a venturi in said intake passageway on the atmosphere side of said throttle valve, an ignition timer, an orifice in said venturi, means connected into said orifice and actuated through changes in the venturi suction obtaining at said orifice for imparting movement to said ignition timer, a second orifice in the intake passageway positioned adjacent to and on the atmosphere side of said throttle valve when in idle position and passing on to the engine side of saidthrottle valve as it is opened 'from idle position, a second means connected to said second orifice and actuated through changes in pressure in the intake passageway obtaining at said second orifice for imparting movement to said ignition timer 4 whereby when the throttle valve is wide open the first pressure actuated means responds to venturi suction and controls the ignition spark advance substantially in direct relation to the engine speed and when the throttle valve is partly open the second pressure actuated means responds to the suction on the engine side of the throttle valve and controls the ignition spark advance in accordance with said last mentioned suction, a connection between the first pressure actuated means and the ignition timer whereby movement of the pressure actuated means imparts movement to the ignition timer, and a lost motion connection between the second pressure actuated means and the ignition timer whereby movement of the second pressure actuated means in a spark advance direction only moves said ignition timer.

5. In an internal combustion engine having an intake passageway provided with a throttle valve for controlling the fiow of motive fluid to the engine, a venturi in said intake passageway. on the atmosphere side of said throttle valve, an ignition timer, an orifice in said venturi, means connected into said orifice and actuated through changes in the venturi suction obtaining at said orifice for imparting movement to said ignition timer, a second orifice in the intake passageway positioned adjacent to and on the atmosphere side of said throttle valve when in idle position and passing on to the engine side of said throttle valve as it is opened from idle position, a second means connected to said second orifice and actuv ated through changes in pressure in the intake passageway obtaining at said second orifice for imparting movement to said ignition timer whereby when the throttle valve is wide open the first pressure actuated means responds to venturi suction and controls the ignition spark advance substantially in direct relation to the engine speed and when the throttle valve is partly open the second pressure actuated means responds to the suction on the engine side of the throttle valve and controls the ignition spark advance in accordance with said last mentioned suction, and resilient means tending at all times to move said ignition timer to retard the spark whereby when the throttle is at idle position substantially atmospheric pressure obtains in both of said prese sure actuated means and the spark is fully retarded, said second means including a one way driving connection with said ignition timer whereby said second means is efiective to actuate said ignition timer to advance the spark when the throttle valve is partly open and the suction at the said second orifice increases but is ineffective to actuate said ignition timer to retard the spark whensaid suction decreases.

MARION MALLORY.

REFERENCES CITED The following references are of record in the file of this :patent;

UNITED STATES PATENTS rm n ug-3 1