US2273352A - Internal combustion engine - Google Patents

Description

Feb. 1 7, 1942; B HANS 2,273,352

INTERNAL COMBUSTION ENGINE Filed April is, 1940 INVENTOR ATTORNEY Patented Feb. 17, 1942 UNITED STATES PATENT OFFICE INTERNAL COMBUSTION ENGINE Edmund E. Hans, Detroit, Mich.

Application April 13, 1940, Serial No. 329,507

7 Claims.

;, The object of my invention is to provide an internal combustion engine especially adapted for use in automotive vehicles, which engine will operate more efficiently when required to accelerate the vehicle.

More specifically, the improvements herein described relate to the ignition systems, particularly ignition distributors having vacuum operated brake means for retarding the timing upon acceleration, In the conventional distributor having a vacuum operated brake, a distributor shaft is driven directly by the engine camshaft. This distributor shaft drives a distributor cam through a centrifugally operated governor, which governor usually comprises a pair of weights pivotally mounted on the shaft to swing outwardly so as to advance the distributor cam as the engine speed increases. The cam is adapted to operate on one or more pairs of contact points to break the primary circuit in the ignition system.

A feature of this type of distributor is that a brake plate is afiixed to the cam to rotate therewith, the periphery of which is in a position to be acted upon by a friction brake when the vacuum in the engine intake manifold is reduced below the normal operating range. This vacuum brake comprises a piston which is reciprocally mounted in a closed cylinder, this piston having a brake shoe on the end adjacent to the periphery of the brake plate. A compression spring urges the piston and shoe into contact with the plate. The outer end of the cylinder is connected with the intake manifold of the engine, so that under normal operating conditions there will be sufiicient vacuum in the intake manifold to draw the piston away from the cam plate against the pressure of the spring to thereby control the timing of the rotor only by the position of the centrifugal governor.

However, when it is desired to accelerate the car, the engine throttle is opened which reduces the intake manifold vacuum to thereby let the piston and shoe move toward the cam plate. When the shoe contacts the plate, a drag is produced upon the plate which counteracts the advancing force produced by the governor. The drag so produced retards the cam a few degrees from that position which it would assume if acted upon only by the governor weights. After the engine has attained a constant operating speed, the vacuum again builds up in the manifold to thereby withdraw the piston from the brake plate and allow the distributor to be timed by the governor according to the engine speed.

.It will be noted that with all systems of the above-mentioned type that the vacuum in the brake-operating cylinder simulates that in the intake manifold. The intake manifold vacuum under normal conditions is considerably higher than under wide-open throttle at low speeds but even with the throttle open, considerable vacuum is still maintained in the manifold. It is for this reason that such distributor brakes may more correctly be said to operate upon the difference in the vacuums present in the manifold under normal and open-throttle positions.

With my improved device the vacuum in the brake cylinder is reduced to zero upon the sudden opening of the throttle valve so that the brake is applied quicker and more positively than heretofore possible.

This old distributor functions with some degree of'satisfaction, but certain disadvantages are unavoidable and these disadvantages are corrected by the auxiliary apparatus shown herein. One disadvantage of controlling the spark-retarding brake solely by a reduction in vacuum in the intake manifold is that the reduction is often small and will not therefore always affect the position of the distributor brake. Furthermore, upon the sudden actuation of the accelerator pedal, with even the most perfectly constructed mechanism of the type described, a noticeable ping will occur during the firing of the next two or three cylinders. This condition is due to a time lag between the instant that the vacuum actually drops off in the manifold and the time that the vacuum brake contacts the brake plate.

To overcome these defects I have provided means which is actuated directly by the engine throttle valve which instantly destroys the vacuum in the brake cylinder upon the sudden opening of the throttle. In this way, the disadvantages of the aforementioned distributor system are overcome and still the advantages of the vacuum brake control are retained.

With these and other objects in view, my invention consists in the arrangements, construction, and combination of the various parts of my improved device, as described in this specification, claimed in my claims, and illustrated in the accompanying drawing, in which:

Figure 1 is a side elevation of a V-type internal-combustion engine having my improved device installed thereon;

Figure 2 is an enlarged view of the engine carburetor and vacuum-controlling device incorporated therein;

Figure 3 is a diagrammatical view, illustrating the operation of the distributor brake and vacuum-control mechanism, and

Figure 4 is a sectional view through an alternate construction, showing a somewhat cheaper and simplified device.

Referring to the accompanying drawing. I have used the reference numeral IE] to indicate the engine proper, said engine having an ignition distributor ll aiiixed thereon and having a fuel intake manifold 12 associated therewith. A carburetor I3 is secured to the manifold l2, said carburetor having a butterfly throttle valve l4 therein which is actuated by an arm E5 on the outside of the carburetor. The arm I5 is connected to a throttle rod l6 which extends rearwardly through the floor boards of the vehicle to an accelerator pedal, not shown in the drawing. In the operationof the vehicle, depression of the accelerator pulls the rod l8 to the left in the drawing to thereby oscillate the arm l5 clockwise and thus open the throttle valve M.

The distributor shown herein comprises a housing I? having a shaft l8 rotatably mounted therein, which shaft has its inner end connected directly to the front end of the engine cam shaft. The outer end of the shaft i8 rotates a distributor rotor iii. A distributor cam 28 is rotatably mounted upon the shaft IE but is fixedly connected to a plate 2!. A pair of centrifugallyoperated weights 22 are pivotally supported by the plate 2! and are resiliently urged inwardly by suitable springs so that when the shaft l8 is rotated in the normal direction of engine operation the plate 2! and cam 22 will be rotated through the centrifugally operated governor weights 22. As the speed of rotation increases, the Weights 22 will swing outwardly and thus advance the position of the plate 21 and cam 28 in the conventional manner.

A cylinder 23 is cast integrally with the distributor housing H, and a piston 24. is reciprocally mounted in the cylinder 23. This piston is urged by a compression spring 25 into contact with periphery of the plate 2 i. The outer end of the cylinder 23 is connected by means of a conduit 26 with the intake manifold [2.

When the throttle valve 54 is gradually opened, the vacuum in the manifold i2 is slightly reduced, but this reduction is not sufficient even though carried by the conduit 23 to the piston 24 to allow the spring 25 to move the piston into contact with the brake plate 2i. However, when the throttle valve l-i is suddenly opened, the vacuum is reduced in the manifold l2 very rapidly; but a short interval of time will elapse before this reduction in vacuum will be transmitted to the cylinder 23 to allow the spring 25 to actuate the piston 24. With the high-speed engines now in use in motor vehicles, as many as three or four of the cylinders may fire before the piston brake 24 will be applied to the distributor plate when the throttle is suddenly opened. Consequently, a noticeable succession of pings will occur each time the engine is rapidl accelerated.

To overcome this defect I have provided an auxiliary vacuum valve 2'! which is interposed in the conduit 28 adjacent to the cylinder 23. A restricting orifice li] is provided in the manifold side of the valve. The valve 27, shown herein, is a poppet-type valve having a valve plunger 28 reciprocally mounted therein, which plunger is urged to its normal position by means of a spring 28. A valve head 38 is formed on the plunger 28 and coacts with a valve seat 39 on the valve 21,. An annular groove 38 is provided in the plunger 28 adjacent to the head 38 so that in the position shown on the drawing the valve transmits the vacuum through the conduit 26 and orifice 48 to the cylinder 23, the head 38 closing the seat 39 due to the spring 29 One end of the plunger 23 is pivotally secured to a dash pot housing 38. The housing 38 i provided with a cylinder 33 herein, in which a piston 3i is reciprocally mounted. The piston 3| is connected to a piston rod 32 which in turn is pivotally connected to the throttle valve arm l5. It is to be noted from Figure 2 that considerable space is provided between the housing 38 and the cylinder 33, which space is used as an oil reservoir for supplying fluid to the dash pot. It may also be noted that ports 3% are provided through the walls of the cylinder 33 at each end thereof, which permits hydraulic fluid within the reservoir 35 to fiow into the cylinder 33 on each side of the piston 8!.

In the operation of the dash pot, a moderate movement of the rod 32, as when the car is being gradually accelerated, will only cause the piston 35 to move toward the left in the cylinder 33, the fluid from one side of the piston flowing through one of the ports 38 into the reservoir and the fluid from the reservoir flowing through the other port to fill the chamber in back of the piston. The spring 28 is of sufiicient tension to hold the dash pot against a moderate force on the piston 35. However, upon the sudden opening of the accelerator, sufiicient obstruction is offered by the ports 3 so that the movement of the piston will cause the housing 38 to follow, thereby momentarily moving the plunger 28 against the retaining force of the spring 29 and momentarily opening the valve head 38.

This sudden movement of the accelerator will oniy momentarily actuate the plunger 28 because as soon as the movement of the piston 3| quits accelerating, the valve spring 29 will cause the housing 88 to return to the position shown. In the operation of the device, the sudden opening of the accelerator will cause the plunger 28 to move to its accelerating position for a fraction of a second, at the end of which time the spring 29 will cause it to return to its normal position, irrespective of the position of the throttle valve.

In the construction shown in Figure 2, the plunger 28 is not only provided with the annular groove 3t but is also provided with an elongated passageway 31 therein, which, when the plunger 28 is withdrawn a considerable distance, connects the cylinder 23 with the atmosphere while closing the orifice 48. Thus, when the plunger 28 is moved to the left in the drawing, the vacuum in the cylinder 23 i instantaneously destroyed. The conduit leading to the intake manifold is closed so that air is not drawn into the manifold. However, the orifice 58 is usually so small that the air entering the manifold therethrough, if no closure were provided, would not be noticeable.

In the construction shown in Figure 2, when the throttle valve is suddenly opened the plunger 28 will be momentarily operated by means of the dash pot 38 to thereby open the cylinder 23 to the atmosphere while closing the conduit leading to the intake manifold. The spring 29 will almost immediately return the plunger 28 to its normal position, but, of course, the vacuum having been relieved in the cylinder 23, the piston 24 will remain in the position where the spring 25 urges it against the distributor brake plate 2|. Thus, upon the sudden opening of the throttle valve, the piston 24 is almost instantly urged into contact with the brake plate 2| by the total reduction of the vacuum within the cylinder 23. Formerly, the reduction of vacuum in the cylinder 23 was only accomplished by the partial reduction of the vacuum within the intake manifold and then only after it had traveled through the comparatively long conduit 26. It should be kept in mind that the actuation of the applicants valve 28 occurs only during a short interval and then only when the throttle valve is suddenly opened. However, this prevents the undesirable ping heretofore unavoidable when the engine was suddenly accelerated.

In this specification and in the claims I have used the term normal position to describe the position of the valve 21 when the head 38 is seated upon the seat 39, and have used the term accelerating position to describe the position of the valve 21 when the head 38 is held away from the seat 39 thereby permitting atmospheric pressure to act upon the brake piston 24.

Referring to Figure 4, I have shown a simplified construction wherein a pneumatic cylinder 4| replaces the housing 30, and wherein a cup-shaped leather washer 42 is slideably mounted in the cylinder 4|. The washer 42 is connected to the rod 32 and the cylinder 4| is connected to the plunger 28. A bleeder vent may, if desired, extend through the washer. In this construction the sudden movement of the rod 32 draws the washer part way out of the cylinder 4| and creates a vacuum behind the washer which urges the cylinder and plunger 28 to follow against the force of the spring 29. If this movement is slow the vacuum so produced will be low, due to leakage past the washer 42 and the flow of air through the bleeder opening, if one is provided, but if the movement is fast the leakage will not be sufficient to prevent the momentary formation of considerable vacuum. This will cause the valve plunger 28 to follow the rod 32 thereby momentarily moving the valve to its accelerating position.

In this alternate construction, no closure is shown for the orifice 40, as this is sufficiently reduced in size so that the air admitted therethrough has no appreciable effect, in diluting the air fuel mixture in the manifold.

Some changes may be made in the arrangement, construction and combination of the various partsof my improved device without departing from the spirit of my invention, and it is my intention to cover by my claims such changes as may reasonably be included within the scope thereof.

I claim as my invention:

1. In an ignition system for motor vehicles, an ignition distributor operated by the motor of said vehicle, said distributor having a vacuumoperated retarding means associated therewith, a throttle for the carburetor of said motor, vacuum control means associated with said retarding means which in a normal position connects a vacuum source to said retarding means to hold said retarding means inoperative and in an accelerating position, connects said retarding means to the atmosphere to cause same to operate, and mechanical means connecting said control means with said throttle in such manner that the sudden opening of said throttle will momentarily 'retard said distributor.

2. In an ignition system for motor vehicles, an ignition distributor operated by the motor of said vehicle, said distributor having a springoperated retarding brake associated therewith, vacuum-operated means for counteracting said spring, a conduit connecting said counteracting means with the intake manifold of said motor, a throttle valve for the carburetor of said motor, a vacuum valve connected in said conduit which, in a normal position, connects said manifold with said counteracting means and in an accelerating position, connects said counteracting means to the atmosphere, and a connection between saidvacuumvalve and said throttle valve which, upon the sudden opening of said throttle valve, causes said vacuum valve to be momentarily moved to said accelerating position to thereby momentarily apply said retarding brake.

3. In an ignition system for motor vehicles, an ignition distributor operated by the motor of said vehicle, said distributor having a spring-operated retarding brake associated therewith, a vacuumoperated piston for counteracting said spring, a conduit connecting said piston with the intake manifold of said motor, a throttle valve for the carburetor of said motor, a vacuum valve connected in said conduit which, in a normal position, connects said manifold with said piston and in an accelerating position, connects said piston to the atmosphere, and means connecting said vacuum valve with said throttle valve so that, upon the sudden opening of said throttle valve, said vacuum valve will be momentarily moved to said accelerating position for the purpose described.

4. In an ignition system for motor vehicles, an ignition distributor operated by the motor of said vehicle, said distributor having a springoperated retarding brake associated therewith, vacuum-operated means for counteracting said brake, a throttle valve for the carburetor of said motor, a vacuum valve associated with said vacuum-operated means, which in a normal position, connects a vacuum source to said means to counteract said brake, and in an accelerating position connects said means to the atmosphere to permit said brake to operate, a spring retaining said vacuum valve in said normal position, and a dash pot connecting said vacuum valve with said throttle valve so that, upon the sudden opening of said throttle valve, said vacuum valve will be momentarily moved to said accelerating position against the pressure of said spring, to thereby cause said retarding brake to be momentarily applied. 7

5. In an ignition system for motor vehicles, an ignition distributor operated by the motor of said vehicle, means for advancing said distributor in proportion to the speed of said motor, a springoperated brake arranged to retard said distributor, vacuum-operated means for rendering said brake inoperative, a conduit extending from the intake manifold of said motor to said vacuumoperated means whereby said brake is applied when the vacuum in said manifold is below a predetermined amount, a throttle valve for carburetor of said motor, a vacuum valve connected in said conduit which, in a normal position connects said manifold with said vacuum-operated means, and which in an accelerating position connects said vacuum-operated means to the atmosphere, and a mechanical connection between said vacuum-operated valve and said throttle valve which upon the opening of said throttle valve momentarily moves said vacuum valve to said accelerating position, for the purpose described.

6. In an ignition system for motor vehicles,

an ignition distributor operated by the motor of said vehicle, means for advancing said distributor in proportion to the speed of said motor, .a spring-operated brake arranged to retard said distributor, a vacuum-operated piston arranged to draw said brake to an inoperative position, a conduit extending from the intake manifold of said motor to said vacuum-operated piston, whereby said distributor is retarded by said brake when the vacuum in said manifold is reduced below a predetermined amount, a throttle valve for the carburetor of said motor, a vacuum valve inserted in said conduit which, in a normal position, connects said manifold with said vacuumoperated piston, and in an accelerating position, closes said manifold to said vacuum-operated piston and opens said piston to the atmosphere, a spring resiliently holding said vacuum valve in said normal position, and a mechanical connection including a dash pot connecting said vacuum valve with said throttle valve so that, upon the sudden opening of said throttle valve, said vacuum valve will be momentarily moved to said accelerating position against the pressure of said spring.

'7. In an ignition system for motor vehicles, an ignition distributor operated by the motor of said vehicle, centrifugally operated means for advancing said distributor in proportion to the speed of said motor, a brake associated with said distributor which, when applied frictionally, retards said distributor, a spring resiliently applying said brake, a vacuum-operated piston associated with said spring which, when moved by the said vacuum, counteracts said spring, a conduit extending from the intake manifold of said motor to said piston, whereby said distributor is retarded when the vacuum in said manifold lowers to a predetermined amount, a throttle valve for the carburetor of said motor, a vacuum valve inserted in said conduit which, in a normal position connects said manifold with said piston and in an accelerating position closes said manifold to said piston and opens said piston to the atmosphere, means for resiliently holding said vacuum valve in said normal position, a dash pot housing connected to said vacuum valve, said housing having a cylinder therein, said housing forming a fluid reservoir around said cylinder, a piston reciprocally mounted in said cylinder, and a rod connecting said piston to said throttle valve, said cylinder having restricting orifices at each end thereof, extending to said reservoir, so that upon the sudden opening of said throttle valve said piston will be moved to thereby momentarily move said dash pot housing and vacuum valve against the pressure of said spring, for the purpose described.

EDMUND E. HANS.

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