US2383749A - Internal-combustion motor and method of operating it - Google Patents

Description

1945- L. M. SHOWERS INTERNAL-COMBUSTIONMOTORS IN METHODS OF OPERATJ ING THEM Filed March 11, 1943 n 2 Sheets-Sheet l 1 m M M R W WITNESSES:

ATTORNEYS.

Aug. 28, W45. L. M. SHOWERS.

I INTERNAL-COMBUSTION MOTORS AND IN METHODS OF OPERATING THEM Filed March 11, 1943 2 Sheets-Sheet 2 ROTATION ATTORNEYS.

, Patented Ana, 1945 p FFlCE INTERNAL-COMBUSTION MOTOR AND METHOD OF OPERATING IT Lewis 'M. Showers, Lansdowne, Pa., assignor to The Pennsylvania Railroad Company, Philadelphia, Pa, a corporation oil Pennsylvania Application March 11, 1943, Serial No. 478,744

L 6 Claims. (Cl. 123-179) This invention relates to internal combustion motors. More especially, it is concerned with internal combustion motors of the spark-fired oil-consuming type, and with methods of operating such motors.

Motors of the kind specifically referred to are ordinarily designed to operate at a relatively low compression ratio, and are accordingly difilcult to start when cold, since the amount of heat developed at that time by compression of the air in the cylinders is in itself insuficient to properly vaporize the injectedfuel oil charges for th purposes of spark ignition;

Amongst the aims of my invention are to overcome the above drawback, i. e., to facilitate starting of spark-fired oil-consuming internal combustion motors; and to improve their performance generally. The attainment of these objectives in practice is made possible, as hereinafter moreiully disclosed; through provision of means, whereby, at starting of the motors, a maximum quantity of air is permitted to enter the cylinders for operation at high compression, and whereby, as the motors heatup, the air supply-is reduced for operation of the motors thereafter at lower compression; and through the further provision of automatic means sensitive to suction variations in the air inlets to the cylinders of the motors for proportionately controlling the amount of fuel injected into the cylinders during normal running.

Other objects and attendant advantages will appear from the iollowing detailed description of the attached drawings, wherein Fig. l is a view in vertical section or an internal combustion motor conveniently embodying the present improvements. I V

Fig. 2 is a staggered fragmentary sectional view oi the motor taken as'lndicated by the angled arrows H-Il in Fig. l.

Fig. 3 is a detail section taken as indicated by the angled arrows Hl-IH in. Fig. 2; and

4 in a diagram showing the operating cycle of thernotor.

The internal combustion motor herein illustrated for the exemplification' of my invention is at the tour cycle spark-ignition oil-consuming type having a single air-cooled cylinder it with a piston ll therein connected, after common practice, by a pitman ii to the crank or power shaft 53. Air admission, and exhaust into and fromthe cylinder it are controlledrespectively' by poppet valves it and it which seat against ports it and ii in the cylinder head" it, said ports communicating respectively with coaxial 55 meeting said i;

outwardly-extending inlet and outlet ducts it and in said head. The valves it and It are biased individually by compression springs 28 and 22, being opened respectively by overhead tappet levers whereof the one for the exhaust valve I5 is shown at 23, in Fig. 1 within; operating rod 2i extending down into the crank case of the motor for actuation by a. rise 26 on the cam shaft 21, which, as ordinarily, is driven from the crank shaft it by intermeshirig spur sears conventionally indicated at 28 and 29. The spark for igniting the fuel charges is afforded by 'a spark plug 30;, which, see Fig. l, is screwed into an opening it in the cylinder headlt, timing of the spark being controlled by suitable means (not Q shown) actuated from.- the crank shaft l3. At a point diametrically opposite ,the spark plug fit,

the cylinder head is is provided with an axially bored boss 32 forconnection of a fuel injecting nozzle 33 which discharges by way of the lower flared portion 34 of the bore in said boss, into the top of the cylinder it above the piston ii. The nozzle 33 is of an approved adjustable type designed to release under a definite regulatable pressure, and the fuel oil is delivered to it, by way of a connecting tube 35, from a reciprocating pump 35 which receives oil by way of a pipe 3i from a suitable source of supply, not illustrated,

and which has a plunger piston 38 actuated by,

another cam rise 3% on the cam shaft ill. The pump 3i) is of standard design having a rotary valve means (not shown) operable by a rack bar ill, see Fig. l, in a well known manne'r.=

For automatically controlling the pump valve in accordance with my invention, 1 have provided a suction responsive device 52 whereof the cylinder at is connected by tubing it to the horisontal branch @512 ct a special angular fitting flit which forms a continuation or the intake duct it of the motor. The piston ill of the suction responsive device 3215 subject to a spring is andv coupled, by a link 89, with the rack bar it of the pump valve means. As shown, the vertical branch lib oi the fitting it? is open at the top for attachment thereto of an air filtering device (not illustrated), and, as showniormedwlth a by-l ass c. Disposed in the branch filth is a horizontalaxis auxiliary throttle 5@, 'which,-in accordance with my invention, is automatically controlled by a bi-metal coil thermostat M lodged within a recess 52 in the cylinder head it of the motor,

the interposed connections includinglan arm tii 'on the shaft it of said throttle, an arm it on the shaft E3 'of the thermostat, and a link bl cono: As later explained, the aur iliary throttle 50 is closed during normal running of the motor. At starting,' when the motor is cold, the auxiliary throttle 50. is open, the tail 53a of the lever 53 acting as a stop therefor in While I have for the'purposes of exemplification herein described my invention in connection with a single cylinder motor of the four stroke cycle type, it is obvious that by suitable modifications within the scope of the appended claims, it can be readily embodied, with attainment of I corresponding advantages, in multiple cylinder governedby a poppet valve 59 which is respon- 'sive to suction against the pull of a compression spring 60 tending to keepit closed. As shown;

the port 58 is located in the horizontal branch 45a of the fitting 45' intermediate the auxiliary throttle B and a main throttle 6| by which the speed of the motor is controlled, said main or control throttle being operable by means of a link rod 62.

In practice the cams on the cam shaft 21 are so arranged as to determine operation of the motor in accordance with the cycle diagrammatically represented in Fig. 4, wherein the rotation of the crank shaft is as indicated by the arcuate arrow at the left of the diagram. As indicated the air induction takes place during 'the whole of the suction stroke of the piston. During the succeeding up-stroke of the piston, the

air is compressed, fuel injection starting approximate'ly after the piston has'reached the mid point of this stroke and the spark occurring shortly before full compression. From the diagram of Fig. 4 it..will be further noted that the exhaust valve is opened slightly before the termination of the succeeding downward or power stroke of the piston, and remains open throughout the succeeding up-stroke of said piston.

As before stated, during normal running of the motor, the auxiliary throttle 50 is completely closed. "I'hus the air for-co mbustionis normally drawn through the port 58 upon opening of the valve 59 by the suction created'during the downward stroke of the piston during alternate rotations of the crank shaft, the speed of the motor being controlled in the usual way by the main throttle 6|. The fuel supplied by the pump 36 is measured by shifting of the rod 4! under control of the cylinder 43, the piston 41 of which responds to variations in the suction attending air induction through the inlet 19. Also as hereinbei'ore intimated, the auxiliary throttle 50 is.

large amount of air thus taken in is compressed to a high degree with incidental rise of its temperature to 'a point at which the fuel will be vaporized for filing by spark ignition. As the motor warms up the auxiliary throttle 50 is gradually moved to'closed position as the thermostat 5| expands, 'whereafter the air will be drawn in Y for injection in the cylinder during each cycle Q motors of either two or four stroke cycle.

Having thus described my invention, I claim: 1. In a spark-fired oil-consuming semi-Diesel internal combustion motor, a cylinder with a piston therein; a fuel injecting nozzle; an air inlet valve; an exhaust valve; an air duct with a throttle for controlling the speed of the motor;

and means for admitting a maximum amount of air into the cylinder for operation of the motor at high compression at starting, and for automatically reducing the air supply as the motor warms up for normal runnin thereafter at lower compression.

2. In a spark fired oil consuming internal combustion motor, a cylinder with a piston therein; a fuel injecting nozzle; an air duct; a main or speed control throttle; an air inlet valve; an exhaust valve; an auxiliary throttle in the air duct ahead of the main throttle; a by-pass extending around the auxiliary throttle; a port intermediate the main and auxiliary throttles by way of which the air inlet and by-pass conimunicate; a suction responsive valve for admitting air into the inlet from the by-pass during normal running of the motor; and automatic actuating means whereby the auxiliary throttle is moved from full-open position for starting of the motor at high compression, to closed position when the motor is heated up for normal running of said motor thereafter at lower compression.

3. The invention according to claim 2, in which the automatic actuating means includes a thermostat within a hollow in a wall of the motor cylinder, and operating connections between the auxiliary throttle and said thermostat.

4. The invention according to claim 1, further including a pump for, delivering the fuel under pressure to the nozzle, said pump havingvalve means for measuring the fuel charge delivered at each injection; and means sensitive to suction variation in the air inlet of the motor for ac tuating the fuel measuring valve means of the pump 5. The method of operating spark-fired semi- Diesel oil-consuming internal combustion motors comprising admitting a large amountof air into- -'the cylinders of the motors for starting 'at high compression; and reducing the air supply as the motors warm up for normal operation of the motors thereafter'at lower compression.

through the port 58 as previously explained, and

the motor operate at normal lower compression. During normal operation, the cylinder device 42 can be relied upon to apportion the fuel charges directly withsuction variations in the air duct II, as a consequence of which the maximum power will be developed by the motor with the most economic consumption of the fuel.

6. The method of operating spark-fired semi- Diesel oil-consuming internal combustion motors comprising admitting a large amount'of air into the cylinders for starting at high compression;

reducing the air supply as the motors warm up for normal running of the motors thereaftenat lower compression; and regulating the fuel LEWIS M. SHOWERS.

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