US2552657A - Cylinder head for diesel engines - Google Patents

Description

' May 15, 1951 J. B.ZIEGLER CYLINDER Hem-won Bissau-memes 2 Shasta-Sheet 1 Filed July :5, 1950 I INVENTOR 4. 6! 68.

dost? 5 Z Patented May 15, 1951 UNITED STATES PATENT OFFICE 9 Claims.

This invention relates to the cylinder head of a Diesel engine and is directed more particularly to a cylinder head embodying the invention of my Patent No. 2,503,186, dated April 4, 1950, and par ticularly the fuel injection and precombustion features disclosed in that patent.

The primary object of this invention is to provide a cylinder head which is mounted removably upon the engine block and which will permit the removal of all valves from the head upon re moval of the head from the block.

A further object is to prOVide an inexpensive and simple cylinder head construction which may be formed from a single casting.

A further object of this invention is to provide a construction by means of which are injector valve associated with the engine cylinder may be operated to open against high compression in the order of 500 pounds per square inch, by the use of a force small in comparison to said compression.

A further object is to provide a device of this character in which the rocker arm controlling the injector valve of the engine is acted upon at a point and in a manner, by a member responsive to the cylinder pressure, so that cylinder pressure is effective upon the rocker arm at two substantially balanced points, and the force required to operate the valve is much less than cylinder pressure.

Other objects will be apparent from the following specification.

In the drawing:

Fig. 1 is a top plan view of the device illustrated partially diagrammatically and with parts shown in cross-section.

Fig. 2 is a fragmentary vertical sectional View taken on line 2-2 of Fig. 1.

Fig. 3 is a fragmentary vertical sectional View taken on line 3-3 of Fig. 1.

Fig. 4 is a View similar to Fig. 3, but illustrating a modified embodiment of the invention.

Referring to the drawings which illustrate the preferred embodiment of the invention, the numeral l designates an engine block having a cylinder bore l2 formed therein and adapted to receive a reciprocating piston M of any usual construction. A cylinder head I6 is mounted upon the top of the engine block I 0, being bolted thereto by bolts (not shown) extending through the bolt holes !8. A suitable gasket 20 will be interposed between the cylinder head and the engine block to effectively seal the parts.

The cylinder head [6 is provided with an injector chamber 22 open at its lower end into communication with the cylinder bore l2 of the engine and having a restricted opening at the center of its upper end to receive and mount a valve guide member 24. This valve guide member slidably receives and guides the reciprocating stem 26 of an injector valve member having an inner valve head portion 28 fitting snugly and slidably within the injector chamber and effectively sealed against the leakage of fluid therepast by piston rings 30. The intermediate portion of the valve member at 32 is of restricted diameter. The outer end portion 34 of the valve includes a conical valve portion 36 adapted to engage a seat 64 at the mouth of the chamber 22.

A chamber 40 .is formed within the cylinder head I6 adjacent to the injector chamber 22 and in communication therewith. This chamber is laterally offset from the engine cylinder bore l2 as best illustrated in Fig. 2. The chamber 40 has an air intake opening 4| adjacent its upper end and an opening receiving a guide 42. Slidable within the guide 42 is the stem 44 of a valve head 46 adapted to engage a valve seat 48 positioned intermediate the height of the cylinder head I 6. In other words, the seat 48 is spaced below the intake opening 4| and above the bottom surface of cylinder head. The valve stem 44 fixedly mounts a plate 50 spaced above the upper end of the valve guide 42, and a coil spring 52 bears at one end upon the cylinder head and at the other end on the plate 50 to normally urge the valve 46 to closed position. In this respect the construction is similar to the construction of the means for normally positioning the injector valve 2836, the said injector valve similarly being provided with a washer or plate 54 upon its stem 26, and the projecting end of said stem being encircled by a coil spring 56 bearing at its lower end upon the cylinder head and at its upper end upon the plate 54.

The lower chamber portion 58, that is the portion of the chamber 40 below the valve seat 48, is of a dimension to permit movement of the valve head 46 between its closed position and a fully open position. The chamber 58 constitutes a precombustion or fuel intake chamber and includes a laterally projecting portion 60 which extends into communication with the injector chamber 22. The point of communication of portion 60 with chamber 22 is located above the lower or valve seat portion 64 at the mouth of chamber 22 and at such a point as to communicate with the restricted intermediate portion 32 of the valve member 28-36 when the latter is in its closed position.

An exhaust chamber 66 is formed in the cylinde head in communication with the cylinder bore I2 in spaced relation to the injector chamber 22 and is provided at its mouth with an annular valve seat 68 against which is adapted to bear the head II! of an exhaust valve member. The chamber 66 communicates with an exhaust manifold at its upper end above the valve seat 68 and has a restricted opening at its upper end in which is mounted a guide 12. The stem it of the valve I is slidable in the guide 72. The valve stem 74 projects above the guide 12 exterior-1y of the cylinder head, and at its upper end mounts a cross-plate I6 against whichbears one end of a Spring I8 whose opposite end bears upon. the

cylinder head.

A transverse bore 80 is formed in the cylinder head off-set from the cylinder bore I2 and with its-axis substantially horizontal. A plug 82 is mountedin the outer end of the bore 89 and serves asmeans for securing a fuel inlet conduit 7 ,84 to the :cylinder head for discharge-of fluid into the chamber 80. The inner-end of the bore 86 is .of'reduced dimension at 86, and a reduced or small size port 83 communicates with the .chamber portion 86 and with the precombustion chamber portion 58, 60., as best seen in Figs. 1 and .2. ,Another port 90extends from the chamberportion 86'to open-at the valve seat 64, as best seen in Figs. 1 and.2. 7 Within the bore 80 is positioned a retainer 92 having a chamber 94 receiving a spherical valve member 96. vided with a restricted port .98 at one end openinginto the chamber portion 86, and with a port ...I0..0. at its upper end. The construction in this particular is preferably such that the valve element .96 may seal the port .100 but is prevented from sealing the port 98, being in this respect similar to the construction in my Patent No. 2,503,186 aforesaid. The cylinder head I6 is provided with a chamber I92 located in spaced relation to the chami'bers 22 and 66, which chamber .is open at the lower end of the cylinder head into communication with the Cylinder bore. At its upper end the cylinder head has a restricted opening adapted to receive a valve guide sleeve I94 within which is slidable the shaft I05 of a plunger I98, preferably of cup shape as illustrated 'in Fig. 3, and also provided with a plurality of piston rings II 0. The upper end of the valve stem I06 projecting from the valve guide I04 has formed thereon a stop or plate H2, and a coil spring II4 encircles the projecting end of the stem I06 bearing at its 7 upper end on the plate H2 and at its lower end upon the upper end of the cylinder head. The "chamber I02 may be closed at its inner end but preferably will have a vent opening or passage therein. In this embodiment it i contemplated that the chamber I02 shall be closed except for the valve guide I94 and the valve stem I06 passing through the opening communicating.

one'po-int from a sealed to an open position The chambered member 92 is pro-' 2,552,657 t V l r r against a compressed charge, that is, a charge within the cylinder bore in the order of 500 pounds per square inch or more. The means here illustrated for the purpose of actuating the valve constitute a conventional push rod I22 which is actuated by a cam shaft (not shown) in the manner Well understood in the art, and which bears at its end portion I22, here illustrated as cup-shaped, against the head or knuckle I24 projecting fromthe rocker arm I26 journaled to rock upon the shaft I223. The rocker arm :26

M will be provided at one point thereof with a projection or bearing surface I39 which engages the free end-of the valve stem I96, and with a second projection or bearing portion I32 which bears against the free end of the stem 26 of the valve 28:46.. The points of engagement of the shafts "26 and 106, respectively, with the rocker arm are preferably spaced substantially equally from the shaft I28 upon which the rocker arm I26 is journaled, when the plunger M9 is ofthe same size or area as the injector valve 28-4-36; Consequently, when there exists within the cylinder bore any charge under pressure, as during the compression stroke of the operating Cycle of the quired to actuate the rocker arm 1 26 for the purpose of opening the valve 2836 against thepressure contained within the engine cylinder :bore. It will be understood, of course, that if the plunger I08 is of a different size or area than valve 2836, then the leverage action'can'be varied by changing the location of the rocker arm portions 1 30-I32 relative to the rocker shaft to secure a balanced action and reduce theeiiort required to operate the rock shaft.

The timing means for actuating the injector valve, the air .intake valve and the exhaust valve will be so arranged that during the compression stroke the "injector valve will be held ajar' until the compression within the cylinder 12 has --reached a predetermined value, for example, a

"The air entrains the liquid fuel which has entered that chamber and discharges it through the passage 98 into the precombust'ion chamber 58, 60. In this connection it Will be apparent that the line 84 will be connected with a source of fuel, as by means of a low pressure fuel pump, so that the liquid fuel is supplied under a predetermined low pressure into the chamber 86. The entrainment of the fuel in the air mixes the fuel and the air, and at the same time the pressure of the air discharged from the cylinder through the passage acts against the valve element 96 to shift the same to the position illustrated in Fig. 1, in which it seals the passage I00 as soon as the air pressure exceeds the pressure at which the fuel is supplied.

After the compression stroke has progressed to a point where a predetermined value of pressure has been reached, say 100 pounds per square inch,

then the valve actuating mechanism serves to completely close the injector valve 28--36 to seal the precombustion chamber at the valve seat 64, and the compression stroke of the piston engine continues until a predetermined time shortly before the engine connecting rod (not shown), which is operated by the piston, reaches its dead center position. At that time the injector valve 28-36 is substantially fully open, this action occurring against the compression within the cylinder which, as stated before, is commonly in the order of 500 pounds per square inch. The highly compressed air within the cylinder will have been heated by its compression to an extent sufiicient to ignite the charge contained within the injector nozzle and the precombustion chamber so that combustion will occur within the precombustion chambers 58, 60 and within the portion of the chamber 22 surrounding the reduced portion 32 of the injector valve. This preignition will occur by the time that the piston has reached dead center and the pre-ignition will force the air-fuel mixture from the injector chamber into the cylinder, thereby causing ignition within the cylinder itself to generate power required for the power stroke of the engine.

It will be noted that during the compression stroke after the injector valve 2836 has been fully sealed, the supply of fuel into the precombustion chamber 58, 60 may continue by virtue of the fact that the pressure of the cylinder will not be effective within the chamber 86, and the comparatively low pressure existing Within the precombustion chamber Will be less than the pressure from the fuel pump, so that the valve element 96 will be unseated. In this connection the valve chamber is so constructed that the valve element 96 is prevented from completely sealing the port 98, and stoppage of fuel supply by an inflow movement of the valve element 96 cannot occur. The operation of opening the injector valve against the high pressure is made possible with the exertion of a force small compared to the force or reaction against which the injector valve must operate to open. This result is accomplished by virtue of the construction illustrated in Fig. 3 which utilizes the application of the force within the cylinder to the rocker arm I26 by the stem I06 of the plunger I08 in opposition to the force exerted by the charge within the cylinder upon the injector valve 28-36 and transmitted to the rocker arm I26 by the valve stem 26. Since the forces on opposite sides of the rocker arm I 26 are substantially in balance, the exertion of only a comparatively slight upward force on the push rod I 20 is required to rock the arm I26 and shift the rod 26 to open the injector valve 26-46. This feature thus simplifies both the construction and the operation of the device and increases the efficiency of the device by reducing the amount of force or effort which is diverted from the work output of the engine for the purpose of operating the valves.

The embodiment of the invention illustrated in Fig. 4 differs from the construction illustrated in Fig. 1 primarily with reference to the nature of the means for reducing the effort or work required to actuate the injector valve. This embodiment of the invention may in all other respects be the same as that illustrated in Figs.

end of the injector valve carries the cross-plate 54, a coil spring 56 encircles the valve shank 26' and the valve guide 24' to normally urge the valve stem upwardly toward valve setting position. The valve is characterized by the inner cylindrical portion 28' encircled by sealing or piston rings 30. The intermediate portion 32' of the valve is of reduced dimension or crosssectional area, and the head 34' of the valve includes the frusto conical portion 36'. It will be observed with respect to this injector valve that it is of substantially the same construction as that illustrated in Figs. 1 to 3 but difiers principally by the absence of any direct connection with a mechanical actuator.

The Fig. 4 construction is further characterized by the chamber I02 which receives the plunger I06 provided with the piston rings or other seals 0'. The chamber I02 has an opening at its upper end receiving the guide member I04 which slidably receives the valve stem I06. In this construction a coil spring I encircles the plunger stem I06 at the portion within the chamber I02, bearing at one end against the plunger I08 and at its opposite end against the guide I64. Consequently, the normal action of the plunger under the influence of its spring I50 is inwardly with respect to the engine cylinder. The plunger rod I06 extends exteriorly and passes through an opening in the rocker arm I26, being provided at its upper end with a head and retainer assembly unit I52 bearing upon the rocker arm I26. The rocker arm I26 pivots about the header shaft or rocker shaft I28 to which one end of the rocker arm I26 is connected. The opposite end of the rocker arm I26 carries the depending knuckle head I24 adapted to be engaged by the cup-shaped head I22 upon the push rod I20.

The two chambers 22 and I02" are placed in communication with one another adjacent their inner ends by the cross-passage I54, and the portions of the chambers inwardly of the injector valve 28-36 and of the plunger I08, together with the cross connecting passage I54, is completely filled with a non-compressible liquid. The top surface of the cylinder head I2 is provided with a depression or oil sump I56 directly above the cross-passage I54, and a recess or bore I58 is formed in the cylinder head, the same having a restricted dimension outlet I60 at its lower end communicating with the cross-passage I54.

The shouldered or bottom portion of the chamber I58 adjacent the restricted outlet I60 is provided with ribs or shoulders I62. A ball valve member I64 fits within the chamber I58, being adapted, when seated upon the ribs I62, to permit the flow of liquid therepast. The upper end of the chamber I58 mounts an annular member I 66 having a central port I 68. This port is adapted to be engaged and sealed by the valve element I64. By reason of this construction it will be apparent that the parts I58, I68 constitute a check valve which permit the inflow of liquid from the oil sump I56 into the chambers 22, I02" and I54, but which prevents the exhaust or discharge of oil or other liquid from said chambers. If then a quantity of oil or other liquid is carried by the sump, it will be apparent that during the operation of the engine the check valve arrangement HEB-I68 will insure constant complete filling of the chamber space 22, I02, I54.

The operation of the device in this case is as follows: Whenever it is desired to open the inthe parts.

amass"! 7 jector valve "28--36", the rocker arm, I26.- is rocked upwardly, i. e. clockwise as viewed in Fig. 4, by the push rod' I20. This action serves engine cylinder is: acting upon the bottom surface of the valve head 34' and of the plunger I 08', and, further, inasmuch as. the pressure acting oppositely upon these two members are equal, there occurs in this. construction a substantial equality of pressure. so that the force required to be exerted upon the push rod I20 and the rocker shaft I26 is sufficient only to overcome the spring loading and the friction of Stated differently, the pressure of the charge'acting upwardly against the plunger lll8 substantially counterbalances the pressure of the engine charge which resists downward movement of the valve head 36. Consequently, it is not necessary that a high mechanical force be exerted for the purpose of opening the injector valve against the compressed charge. Therefore, it will be apparent that this construction, which utilizes liquid or hydraulic pressure, a force transmission and pressure equalization, possesses substantially the same advantages as the embodiment above illustrated in which equalization of operating forces is secured through solely mechanical means. In other words, by this device applicant is taking advantage again of the pressure or of the charge within the engine cylinder to assist in performing the work of opening the injector valve in a direction which normally would be resisted by that same engine charge.

While the constructions herein described and illustrated constitute preferred embodiments of the invention, it will be understood that other constructions may be made within the scope of the appended claims without departing from the spirit of the invention.

I claim:

1. In a Diesel engine having a cylinder, a cylinder head having an injector chamber adapted to communicate with said cylinder, an injector valve for controlling communication between said chamber and cylinder andadapted to be opened against high cylinder pressure, a valve actuator, and a member responsive to the pressure in the cylinder and acting in opposition to said valve to normally balance the pressure reaction exerted upon said actuator by aid valve.

2. In a Diesel engine having a cylinder, a cylinder head having an injector chamber adapted to communicate with said cylinder, an injector valve for controlling communication between said chamber and cylinder and adapted to be opened against high cylinder pressure, a valve actuating rocker arm pivoted intermediate its ends about a fixed axis, said valve having a portion projecting from said cylinder head into engagement with said arm, and a member responsive to the pressure in the cylinder and having a portion projecting from said cylinder head into engagement with said arm spaced from the point of engagement of said valve portion and arm, said arm axis being spaced from and positioned between the aforesaid points' of engagement of said valve portion and pressure responsive member with said arm.

3. In a Diesel engine having a cylinder, a cylinder head having an injector chamber adapted to communicate with said cylinder, an injector valve for controlling communication between said chamber and cylinder and adapted to be openedagainst high cylinder pressure, a valve actuating rocker arm pivoted intermediate its ends about a fixed axis, said valve having a portion projecting from said cylinder headinto engagement with said arm, and a member responsive to the pressure in the cylinder and having a portion projecting from said cylinder head into engagement with said arm spaced from the point of engagement of said valve portion and arm, said arm axis being spaced from and positioned between the aforesaid points of engagement of said valve portion and pressure responsive member" with said arm, said valve and pressure responsive member being of substantially equal area: and said points of engagement being substantially'equally spaced from said arm' axis.

4. In a Diesel engine having a cylinder, a cylinder head having an injector chamber adapted to communicate with said cylinder, an injector valve for controlling communication between said chamber and cylinder and adapted to be opened against high cylinder pressure, a valve actuating rocker arm pivoted intermediate its ends about a fixed axis, said valve having a portion projecting from said cylinder head into engagement with said arm, and a member responsive to the pressure in the cylinder and having a portion projecting from said cylinder head into engagement with said arm spaced from the point of engagement of said valve portion and arm, said arm axis being spaced from and positioned between the aforesaid points of engagement of said valve portion and pressure responsive member with said arm, the ratio of the spacing of said points of engagement from said arm axis being substantially inversely-proportional to the ratio of the areas of said valve and pressure responsive member.

5. In a Diesel engine having a cylinder, a cylinder head having an injector chamber adapted to communicate with said cylinder, an injector valve for controlling communication between said chamber and cylinder and adapted to be opened against high cylinder pressure, said cylinder head having a second chamber and a passage connecting the inner ends of said chambers, said valve including an inner sealing head portion, a plunger shiftable in and sealing said second chamber, said inner sealing valve head portion and said plunger defining a sealed chamber filled with liquid, and a rocker arm for shifting said plunger in its chamber.

6. In a Diesel engine having a cylinder, a cylinder head having an injector chamber adapted to communicate with said cylinder, an injector valve for controlling communication between said chamber and cylinder and adapted to be opened against high cylinder pressure, said cylinder head having a second chamber and a passage connectingthe inner end of said chambers, said valve including an inner sealing head portion, a plunger shiftable in and sealing said second chamber, said inner sealing valve head portion and said plunger defining a sealed cham,- ber filled with liquid, and a rocker arm for shifting said plunger in its chamber, and means for replenishing liquid in said sealed chamber.

'7. In a Diesel engine having a cylinder, a cylinder head having an injector chamber adapted to communicate with said cylinder, an

injector valve for controlling communication between said chamber and cylinder and adapted to be opened against high cylinder pressure, said cylinder head having a second chamber and a passage connecting the inner ends of said chambers, said valve including an inner sealing head portion, a plunger shiftable in and sealing said second chamber, said inner sealing valve head portion and said plunger defining a sealed chamber filled with liquid, and a rocker arm for shifting said plunger in its chamber, said cylinder head having an oil sump positioned above said sealed chamber, a passage connecting said sump and sealed chamber, and a check valve in said passage for admitting liquid into said sealed chamber.

8. In a Diesel engine having a cylinder, a cylinder head having an injection chamber adapted to communicate with said cylinder at a valve-seat-defining mount portion, a precombustion chamber communicating with said injection chamber, an air intake passage communicating with said precombustion chamber, a fuel intake passage communicating with said precombustion chamber, and a passage branching from an intermediate portion of said fuel intake passage and open at said valve-seat-da fining injection chamber mouth, a valve for controlling air flow from said air intake passage into said precombustion chamber, means for supplying fuel to said fuel intake passage, and an injector valve including a sealing portion adapted to bear against said seat and an inner portion having a snug fit in said chamber.

97 In a Diesel engine having a cylinder, a cylinder head having an injection chamber adapted to communicate with said cylinder at a 10 va1ve-seat-defining mouth portion, a precombustion chamber communicating with saidinjection chamber, an air intake passage communicatin with said precombustion chamber, a fuel intake passage communicating with said precombustion chamber, and a passage branching from an intermediate portion of said fuel intake passage and open at said valve-seat-defin JOSEPH B. ZIEGLER.

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

UNITED STATES PATENTS Number Name Date 2,593,186 Ziegler Apr. 4, 1950 FOREIGN PATENTS Number Country Date 5,690 Great Britain Mar. 7,. 1911

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