US1802848A - Fuel system - Google Patents

Description

April 28, 1931. c. E. SUMMERS FUEL SYSTEM Filed June 5 192 3 Sheets-Sheet 1 gmwnio'a Ap 1931. c. E. SUMMERS 1,802,848

FUEL SYSTEM Filed June 5 92 3 Sheets-Sheet 2 37141. vJo,

Guam

April 28, 1931.

C. E. SUMMERS FUEL SYSTEM Filed June 5 1925 5 Sheets-Sheet 3 Patented Apr. 28, 1931 UNITED STATES PATENT OFFICE CALEB E. SUMMERS, OF DETROIT, MICHIGAN, ASSIGNOR TO GENERAL MOTORS RE- SEARCH CORPORATION, OF DETROIT, MICHIGAN, A CORPORATION OF DELAWARE FUEL SYSTEM Application filed June 5,

This invention relates to improvements in the fuel system for explosive motors. The invention is primarily intended for use on motor vehicles although itsadvantages, when so used, may also be present, perhaps to a less extent, in other relations. Furthermore, while designed for use on an engine of the four cycle type its characteristics are such as to render it useful also on engines of the two cycle type.

It is, then, the object of the invention to provide a fuel system having parts co-related to obtain maximum etlieiency; one which will use advantageously explosive fuel ditlicult of vaporization; bne which is adapted for all conditions of speed, load, temperature and pressure.

The duty of a fuel system is to bring fuel from a storage tank at the rear; meter it correctly for every condition of speed, load, and temperature; and introduce it in an atomized state so it is carried directly, borne by the air charge, into each separate cylinder. The fuel should be automatically regulated for every requirement, as, extra rich for cold starting, full power mixture for full load, and maximum economy mixture for part'load. The fuel system should also be so designed as to get the maximum air charge into the motor at full load. To accomplish this, preheating must be eliminated, and also any resistance to the entrance of the air, such as valves, is undesirable. It is desirable even to go further, and so construct the manifold that an air ram condition is produced, which actually supercharges the engine, obtaining more power from a given bore and stroke, yet without increasing the speed or compression (which latter two carry with them certain disadvantages). This results in 'a lighter motor for equal power, which not only saves cost of material, but saves weight, which again results in better performance for the same power. Also a smaller engine with less cooling surface, of less mechanical friction, results in greater economy. It is, therefore, a fundamental gain to obtain as great a weight of charge as possible in a given cylinder.

For the attainment of the objects enumer- 1926. Serial No. 113,933.

ated, the structure herein described and illustrated in the accompanying drawing has been devised.

In the drawing Figure 1 shows an internal combustion engine in end elevation, partly in section.

Figure 2 is a side elevation with the fuel system in vertical section.

Figure 3 is a horizontal section on line 33 of Figure 2.

Figure 4 is a horizontal section on 4-.4 of Figure 2.

Figure 5 is a vertical section of a detail.

Referring by reference characters to the drawing, numeral 1 shows an internal combustion engine having exhaust manifold 2. The cylinders 3 are surrounded by a Water jacket 4. Over the cylinder block is a 00- operating head 5 which may be shaped as shown, and in which head are mounted the spark plugs 6. Associated with each cylinder is an intake valve 7 affording communication with the combustion chamber 8 and the manifold 9. At this point there is a departure from the conventional arrangement. There are a plurality of tubular manifold members which are secured to openings 9 in the cylinder block and extend downwardly and are united by a common casting 10 controlled by the usual throttle valve 11. By this type of manifold construction each cylinder draws in its air through a tube which is not being used at the time by any other cylinder, that is, there is no overlapping of induction flow to two cylinders through the same tube. By proper selection of length and diameter of the tube, the ram efl'ect will be varied along the speed range so as to obtain the maximum ram at the speed desired. For instance, if high torque at high speed is the principal requirement, the ram will be relatively short and large in diameter; if high torque at loW speed is more important, the ram will be relatively long and of small diameter. In practice, for application to an Oakland engine, the ram tubes will be approximately inside diameter and 19" long. In the construction of a ram, it is desirable to have the inner surface smooth and all bends over as long radius as possible.

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Where there isv a change in section, as where the ram enters the ort, the increase in diameter should be gra ual so there is no distant ledge which will cause eddy currents of the air and dissipate energy in fluid friction.

Air pumps 12, of which there may be two, are driven from the motor as by a shaft 13, gearing 13', shaft 14, universal 15, crank shaft 16, connecting rods 17 and piston 18. The air pumps draw air by means of an inlet valve 19 through which air enters from a tube 21. Tube 21 takes its air from any convenient source but preferably from the crank case since in that way the air would be free from dirt and contain a desired quantity of oil mist. A resistance valve, not shown, is used in pipe 21- to maintain a definite vacuum. This vacuum is communicated by pipe 23 to float chamber 24 having a float 25 controlling a valve 26. Obviously the degree of vacuum must be sufiicient to lift the fuel from the storage tank to the float chamber under the most adverse conditions and maxium demand, that is, it must lift sufficient fuel for maximum engine speed at full load when climbing the steepest grade so the car will pull on low gear and with the storage tank practically empty.

The air inlet valve 19 is mechanically operated and driven by shaft 27 geared by gears 28 and 56 to the crank shaft. The fuel for the float chamber is obtained by a pipe 29 extending from the usual gas reservoir at the rear of the car and. enters a chamber 30 beneath the float chamber. Here it is filtered by filter 32 and passes through the valve 26 into the float chamber.

To meter the fuel one or more rotating cylinders 33 are used. The two cylinders shown are mounted so as to be capable of simultaneous vertical reciprocation and each is mounted for rotation on its own longitudinal axis. Each cylinder rotates in a chamber filled with fuel entering from the float chamber through passage 34 (see Figure 3). Shoes 35 actuated by a spring 36 mounted on a post 37 hold about 90 of the circumference of the cylinders 33 against the encircling walls of the fuel chamber. The cylinder walls are provided with pockets 38 of variable depths, being deepest at their lowermost portion. These pockets become filled with fuel during the rotation of the cylinder within the fuel chamber. The pockets 38 come into registration with the openings 39 in the fuel chamber as the cylinder rotates on its axis and the openings 39 communicate bymeans of pipes 40 with each of the valve chambers, as clearly shown in Figure 1. The pipes 40 terminate in nozzles 41 situated just beneath the intake valves. The fuel pockets 38, when rotated into registry with opening 39 also register with elongated openings 44 in the walls of the fuel chamber, said elongated openings 44' communicating with a motor is at its lowest temperature. For operation under normal conditions of temperature and for part load, the metering cylinder is moved downward so the fuel in the lower portion of the fuel pocket does notdischarge through the port, but is carried past it. The means for moving the metering cylinder as itctuated by temperature and load are as folows:

The shaft45, which drives the metering cylinders, extends downwardly as at 46.

This shaft and its companion shaft 47, which drives the other metering cylinder, are driven by gears 53 on the shafts. Gears'53 engage gear 55, which is integral with the gear 57,

rotated by the gear 56 on the crank shaft as shown in Figure 1 and Figure 3. The shafts are coupled by a yoke 48 which permits them to rotate independently but causes them to move together in any vertical movement. The yoke 48 has a pivot shaft 49 upon which is a lever 50, one end of which is connected to a piston 51 of a cylinder 52.

Cylinder 52 is connected by a conduit 58 entering the manifold at 59 just above the throttle 11. A spring 60 within cylinder 52 exerts its pressure upwardly upon piston 51. It is evident that when the vacuum in the manifold increases, due to the closing of the throttle, the piston 51 will be drawn downwardly carrying lever 50, yoke 48 and the metering cylinders. spring of suitable tension and by properly shaping the pockets 38. it is possible to make the quantity of fuel discharged by the metering cylinders correspond to any degree of throttling, since the fuel content is reduced in proportion to the absolute pressure of air in the manifold, it being understood that the fuel in the fuel pocket 38 beneath the discharge opening 39 is not driven out through the conduit 40.

Air expands with increase in temperature. Therefore, a cylinder full of air at minus 20 F. willrequire more fuel than the same volume at 200 F. Provision is made, therefore, to regulate the fuel in proportion to temperature. A bellows 61 is provided separated by partition 62 from an inclosure 63. The inelosure 63 is in communication by means of a tube 64 with a chamber 65 located within the water jacket of the motor so that the water temperature is imparted to it. The bellows 61 is entirely filled with oil or other By the selection of a non-volatile liquid and it communicates by means of a small hole 61' through partition 62 with enclosure 63, the lower-most part of the enclosure also containing oil.

The size of the enclosure is so selected that when the bellows is fully extended downward, liquid from the enclosure may flow through a small hole in the partition entirely filling the bellows, with a certain reserve left in the enclosure. Also when the bellows is at its upward limit, thereby forcing the liquid out through the aperture in the partition into the'enclosure, the enclosure will not be entirely filled. The purpose of the liquid is to give stability to the bellows so that when sudden shocks are imparted to the bellows through the sudden and forceful change in the vacuum that controls the piston 51, the shock imparted to the bellows through the lever and the connection will not cause it to move suddenly, because a considerable time element will be required for the oil to be forced through the aperture in the partition. However, on the other hand, when the temperature of the water jacket changes and causes an expansion of the air in the cham-,

ber, the persistent pressure exerted on the surface of the liquid in the enclosure will cause the liquid to flow through the aperture, thus extending the bellows; and conversely when a contraction of the air in the chamber produces a partial vacuum, the air pressure exerted on the external walls of the bellows will force the bellows upward, depressing the portion of the liquid contained therein into the enclosure. Therefore, by this arrangement we have a mechanism which is resistant to sudden shocks, but regulates with accuracy to compensate for changes in the temperature of the motor. The chamber may be placed at any position to have the temperature of any portion desired imparted to it, but it is thought the water represents a fair index of the temperature of the working fluid in the cylinder during the intake stroke. The bellows 61 is secured to the cast ing 67 by its upper end so that its expansion has the effect of pulling down on leaf spring 68 imparting downward motion to the yoke 48 and the metering cylinders.

The bellows has been described as correcting for variations in temperature, but it is evident that it will also correct for changes in barometer or altitude. Suppose a motor so equipped is placed in an airplane and is results in reducing the quantity of fuel which is being fed to the motor so a balanced mixture is maintained.

We have, therefore, combined in one unit means for elevating the fuel from the storage a spray, produced by compressed air, so thedistribution should be perfect and the introduction positive and almost instantaneous. The ram manifold, which is possible with this type of metering, increases the air charge yery appreciably through the ordinary driving range.

. From the combination of ram manifold, cold carburetion and perfect distribution, the power of the engine may be increased by approximately 20%. The method of fuel introduction is intended to insure easy starting at any temperature. It is expected that an engine equipped as described will start and operate satisfactory on half kerosene and half gasoline, even in winter. Fuel economy will be uniformly high whether the car is driven by an expert or an amateur, since all regulation is automatic.

I claim 1. In combination with an internal combustion engine, amechanical metering device therefor comprising a fuel conduit communicating with said engine, a fuel chamber, a metering member rotatable and reciprocable therein, said metering member having a pocket to receive fuel from said chamber and deliver it to said conduit, means automatically controlled to reciprocate said metering means and thereby predetermine the amount of fuel discharged from said pocket to said conduit.

2. Mechanical metering mechanism for an internal combustion engine having a cylinder and an intake manifold comprising a fuel I chamber, a plurality of metering members therein, power driven means to rotate said members, delivery conduits from said chamber to said cylinder for supplying the engine with-fuel, said metering members having pockets to be filled with fuel from said chamber and to discharge into said conduits, pressure means to force said fuel through said conduits, and mechanism automatically actuated by variations in manifold suction, engine temperature and external pressure to reciprocate said metering members jointly to thereby vary the area of said pockets in registering with said conduits.

3. The combination of elements enumerated in claim 2, said mechanism comprising rod means on each metering member, a device responsive to changes in manifold suction operative upon one arm of said lever and a device responsive to changes in temperature and pressure operable upon the other arm of i said lever device, the other arm being actuated by said temperature control.

4. The combination of elements enumerated in claim 2, said mechanism comprising a head connected to said metering members, a fixed cylinder, a piston therein connected to said head, apipe connecting said cylinder with the manifold and yielding means within said cylinder whereby the suction of the manifold and the yielding means cooperate to reciprocate said metering device to vary the quantity of fuel delivery.

5. The combination of elements enumerated in claim 2, said mechanism comprising a head connected to said metering members, an expansible'and contractible member being connected to said head, whereby changes in motor temperature control the quantity of fuel supplied by said metering device.

6. In combination, an internal combustion engine, a float chamber for fuel, a mechanically motor operated air pump, pipe means between said air pump and said fuel chamber whereby the fuel chamber is supplied with fuel by the suction stroke of the pump, other pipe means associated with said air pump and fuel chamber and engine whereby fuel is delivered from said chamber to said engine by air pressure caused by the discharge stroke of said pump.

7. In an internal combustion engine having a cylinder and intake manifold, a fuel chamher, a first conduit from said chamber to said cylinder, a second conduit to supply said chamber with fuel from a source below said chamber, an engine operated air pump, an inlet pipe therefor, a pipe from said inlet pipe to said fuel chamber, mechanism including a third conduit between said pump and the first conduit, whereby the suction stroke of said pump operates to maintain a supply of fuel in said chamber through the second conduit and whereby the discharge stroke of said pump operates to deliver a supplyof fuel under air pressure from said chamber to said cylinder through said first conduit.

8. The invention defined by claim 7 together with an engine operated metering de vice in said chamber to predetermine the quantity of fuel to be delivered.

9-. The invention defined by claim 7, together with an engine-operated metering device in said chamber to predetermine the quantity of fuel to be delivered, and mechanism responsive to changes in manifold suction and also to variations in temperature and pressure to control the metering device.

In testimony whereof I aflix my si nature. CALEB E. SUM ERS.

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