US1747578A - Automatic control for internal-combustion engines - Google Patents

Description

Feb. 1s, 1,930.

D. DAvlsoN ET AL 1,747,578

AUTOMATIC CONTROL FOR INTERNAL COMBUSTION ENGINES Filed Jan. .15, 1927 s sheets-Sheet 1 ATTORNEYS.

Feb. 18, 1930. D. DAvllsON ETAL 1,747,578

AUTOMATIC CONTROL FOR INTERNAL COMBUSTION ENGINES Filed Jan. 15, 1927 3 Sheets-Sheet 2 A TTORNE YS.

Feb. 18, 1930. D. DAvlsoN Er AL 1,747,578

AUTOMATIC CONTROLFOR INTERNAL COMBSTION ENGINES Y Filed Jan. 13. 192'? s Vsnee'sshe' 3 TORNEYS.

Patented Feb.. i3, E93@ DAVID DAVISON, OF OAKLAND, AND WILLIAM L. COR-SON, DECEASED, LATE 0F ALA- MEDA, CALIFORNIA, BY JOSHUA A. ROBERTS, ADMINISTRATOR, OF ALAMEDA,V CALIFORNIA, ASSIGNORS TO UNION GAS ENGINE COMPANY, OF OAKLAND, CALI- FORMA, A CORPORATION 0F CALIFORNIA AUTOMATIC CONTROL FOR INTERNAL-COMBUSTION ENGINES Application led January 13,-1927. Serial No. 161,006.

This invention relates to Diesel engines of the solid or mechanical injection type and particularly to automatic fuel regulation and control.

Diesel motors of the mechanical injection type are provided with a spray nozzle, a valve in the nozzle to regulate the discharge of fuel, a pump to deliver fuel.to the nozzle and means for regulating the quantity of fuel delivered to the nozzle. Engines of this type are usually subjected to considerable variations in speed and load conditions when in operation and means must, accordingly, be provided to vary the quantity of fuel injected.

Varying load and speed conditions are ordinarily taken care of either by regulating the lifting period of the spray nozzle valve or by changing thev quantity of fuel delivered to the spray nozzle by the fuel pump. In actual practice, it has been discovered that a change in the quantity of fuel injected or regulation of the spray valve liftor, in other words, increasing or decreasing the spraying or injecting period is not sufficient if efficiency and good combustion is considered as another factor enters to-wit: that of pressure regulation. It has been found that the pressure on the fuel should reach maximum during a prolonged spraying period and considerably reduced during a shorter spraying period. rlhis is due to the fact that a greater quantity of fuel requires more energy or pressure to insure atomization, while a smaller quantity of fuel requires less energy or pressure. lt has also been discovered that better control and efficiency is attained when the spraying period and the quantity of fuel injectedare controlled in unison. Again, it has been found that the pressure on the fuel should be changed as the spraying period and the quantity of fuel is varied and further that the spraying period, the quantity of fuel injected and the pressure maintained should be changed with variations in speed and load.

The object of the present inventionis to generally improve and simplify the construction and operation of -regulating devices of the character described; to provide means whereby the spraying period, the quantity of fuel injected and the pressure maintained may be regulated in unison and further t0 the spray nozzle and aportion of the mech-l' anism actuating the same,

Figure 4 is an enlarged sectional view of the fuel punip and a portion of the mechanism actuating the same, v

Figure 5 is an enlarged sectional View of the governor.

Referring to the drawings, in detail, and particularly Figure 1, A indicates the cylinder of a Diesel engine; B the head; C the spray nozzle; D the fuel pump; E the cam shaft whereby the exhaust and inlet valves of the motor are actuated and F a governor which is driven by the cam shaft 'and the function of which will hereinafter be described. f

The spray nozzle is best illustrated in Figure 3 of the drawings. It consists of a body portion 2 which projects through the head B of the cylinder and which terminates in a spray tip 3. Mounted interior of the body and normally forming a closure for the spray tip is a needle valve 4. This valve projects through a stuffing box 5 and its upper or projectingend is provided with a collar 6 which is engaged by a wedge-shaped member 7. Engaging the wedge-shaped member is an intermediate rocker arm 8 which, in turn, is actuacted by a main rocker arm 9'. This rocker arm is, in turn, actuated by a fuel cam 10I secured on the cam shaft E and the needle valve is thus intermittently raised with relation to the spray tip so as to permit injection of the fuel. The quantity of fuel injected de- @ne form as engines o thischaracter laresubjected to varyingload conditions means mustbe employed for regulating ,the opening period of terminesthe power output ofthe cylinder and the valve. The means employed in the. present instance, is the wedge-shaped member 7.

' .This member is actuated bythe governor F through a rocker arm and a series of link connections, as Will hereinafter be .described.`

Sufiiceth to say that a longitudinal movement is imparted to the Wedge member 7 and that this determines the lifting or opening period of the valve.

Inactual practice, ithas been found that vvit `is not only necessary to .regulate the quantity of fuel injected, but itis also necessary to regulate the quantity of fuel delivered to the spray nozzle and further to regulatethe pres sure maintained'on the fuel. Themeans` employed in the 'present instance is a variable dischargeor metering pump, previously referred to and indicated atD. This pump is best illustratedin Figure 4and it consists of a cylinder or body portion 11 in which is formed a cylindrical chamber 12." The upper" endof this cylindrical chamber is provided with a stuffing box 13 through which extends a plunger 14. This plunger .is pivotally ,con-

nected as at 15 (see Figure '1) with'a strap 16 which, in turn, is connected with an eccentric 17 secured on the cam shaft. This eccentric imparts a reciprocal movement to the plunger and fuel in the form of oil' or the likelis thus intermittently admitted and discharged by the pump. The fuel is admitted through an inletvpipe 18 and discharged through a pipe 19 which connects with the upper end of the spray nozzle C, as indicated at 19. One side of the cylinder 11 is extended as shown at 20 and this extension forms a housing for an inlet valve 21 and a discharge valve 22, these valves being interposed between the respective inlet and discharge pipes 18 and 19, as illustrated.

An intermediate chamber 23 is formed between the valves and this communicates with the cylindrical chamber 12 throughA means :of a port 24. The fuel is admitted through the inlet pipe 18 during upward movement stroke vofthe, plunger 14 permits a certainl ofthe pump plunger 14 as the inletl valve will be opened both by suction and mechanical operation, during reversemovement the oil admitted will be discharged partly through the inlet valve and-partly through the dis'- charge valve 22 during the return stroke ofv the plunger. In fact the lvaried discharge or metering action obtainedby the pump Adepends uponthe. mechanical closing of the inlet valve, as retension of the inletvalve in open position during a portion of the return quantity of the oiladmitted to be returned.

" through .the inlet valve to the suction line 18 and the remaining oil to be. discharged through the valve 22 when the inlet valves shaft 30 and the eccentric 29 in'the direction' closed.' v The .mechanical voperation of the inlet valve'A is .obtained by the, employment of a plunger rod 25. -This extends through a' vstuiring box 26 mounted in the lower end of the housing 20 and it is connected through .means f 4'a link 27 to a rocker arm 28 which oscillates' on an eccentric 29 which is secured on a controller shaft 30 hereinafter to be described. The opposite end of the rocker arml 28 is connected through means of a link 31 (see Figure 1) with the plunger V14 at the v point indicated at 32. A reciprocal movement is thus imparted tothe link in unison with the movenient of the plunger 14 and this reciprocal movement is, in turn, transmitted to oscillate the vrocker arm 28. This, in turn,

er 25 which alignsjv'vith the inlet valve 21 and by regulating the position of the rocker arm. 28 the closing period ofthe inlet valve 21.

may be determined and similarly theyquantifty of oilbypassedor returned; 1 If it is de- .imparts a reciprocal movement to the plungsired toretard closing of the inlet# valve during `thedownward 4ordischarge stroke of the plunger 14, it is merely necessary to rotate the to the controller shaft 30 and its outer end swings overa segmental rack bar 34 with which it may be interlocked by means of a spring pawl 35. Hence, by swinging the lever 33 manually, any position of the shaft 30, eccentric 29 and plunger 25 may be obtained.

The other means employed forV controlling,

the closing of thev inlet valve is-the governor F. This governor imparts a rockingvmo'vement 37 controller shaft 30. This crank arm is connected with the arm 36 through means ofv a to an arm 36 which is secured on a shaft crank arm 38 is secured on the end of the 1F15 v link39 and rocking movement of the .arm

36 is thus transmitted to elevate or lower the eccentric, the rocker arm 28 andthe plunger' 25v and means have, accordingly,

een provided* Wherebythe closing 'period' of the valve may be either manually or automatically regulated. The arm 36 which is actuated by the governoralso'serves a func-v tion of controlling the position of the wedge member 7 whereby the openingv period of the'fuel` injecting valve or spray nozzle is controlled. This is accomplished by providing a bellcrank or the like such as' indicated at 40. This s pivotally mounted as. atfli on top of the cylinder head. The upper end of the bellcrank is connected with the wedge member 7 through means of ailink 42 and the lower end of the bellcrank is connected with the arm 36 through means of a link 43. Hence, when rocking movement is transmitted to the arm 36 through means of the governor, two automatic regulations are simultaneously attained, to-wit: automatic regulation of the quantity of the fuel discharged by the pump andautomatic regulation of the fuel injector or spray nozzle valve.

The governor employed is also an important feature of the present invention as it does not only serve the function `of automatically regulating the injection or spray nozzle and the quantity of fuel delivered thereto, but it also serves the function of maintaining such automatic regulation during a wide range of engine speeds. A Adescription of the governor mechanism is, accordingly, thought necessary and reference will be made to Figure 5.

By referring to this drawing, it will be noted that the governor consists of 'a lower housing section 45 and an upper housing section 46. Extending through these housing sections is a, governor shaft 47 and secured thereon in the usual manner is a cross head arm 48 in the outer ends of which is pivotally mounted as at 49 bellcrank arms 50 which carry ily halls 51.. These are Connected in the usual manner by tension springs 52 'and they, furthermore, function in the usual manner, that is, they are actuated by centrifugal force during the revolving movement of the shaft 47 and as such have a tendency to swing outwardly against the tension of the spring 52. -The inner ends of the bellcranks are provided with rollers 53 and these in turn,`

shaped rocker arm 56 secured "on the inner end of the shaft 37 and engaging an" annular groove or collar 57 formed on the-sleeve 55.

The-outward movement of the iy balls 56 andthe downward movement of the sleeve 55 is in the present instance, resisted by a plu-' rality of springs such as indicated at 58 and 59. The lower ends of the springs are supported on the plate 60 which is lvertically slidable on the governor shaft 47, while the upper ends engage a plate 61 which, inturn,

60 and 61 together with the springs 58 andl 59 are secured against rotation by passing rods 63 through the springs 58 and the plates and by securing one of the rods to the governor housing. This feature is, however, of no material importance and further description thereof is thought unnecessary.

An important feature is, however, that of providing means whereby the tension of the springs 58 and 59 may be varied. The means employed in the present instance is a crankv arm 64 which engages the lower plate 60. This crank arm is secured on thelshaft 65 which is journalled inthe governor housing 45 and extends through one side thereof. The outer end of this shaft is provided with a manually controlled lever 66 (see Figure l) and this lever, in turn, carries a pawl 67 which engages a rack bar 68. The position of the controlling lever 66 and the rocker arm 64 maythus be determined and maintained and the tension of the springs 58 and 59 is, accordingly, regulated. These springs coact with the governor spring 52 through means of the sleeve 55 and the governor bellcranks 50 and more or less resistance may Athus be imposed against the centrifugal action Aoutward orv centrifugal movement of the Hy balls 56 is thus placed at a minimum and the speed of the engine will be slow' as-the y balls will swing outwardly the moment a predetermined speed is exceeded. Such outward movement is transmitted to the sleeve 55 and through the rocker larm- 56 and shaft.

37 to the controlling arm 36. This, in turn, actuates the fuel pump and the spray nozzle in such a manner that the spray valve is given its shortest opening period and the pump its smallest discharge. y

On the other hand, if maximum or full speed is required, the controlling lever is swung to lits uppermost position shown in Figure 1. Such movement placesthe springs 58 and 59 under maximum compression and a greater load is thus placed on theflyballs of the governor and they will be restricted to outward movement vuntil a maximum speed is obtained. l Any intermediate speed may similarly be maintained by moving the controlling lever to any intermediate position between the maximum and minimum speeds.

It is'thus seen that the pump suction valve and spray nozzle fuel valve controls are synchronized and operated by the governor ysimultaneously at minimum and maximum governing. This is of further importance as 'it eliminates thebypassing of high pressure fuel.l There is, however, installed, an emergency relief valve in the oil delivery pipe 19, but this functions very rarely and as it is more or less a common expedient in installations of this character, illustration thereof, has been eliminated. v

Itwas previously stated that the'quantity of fuel discharge by the pump wasunder'b'oth ma-nual and automatic control. Such an arrangement "is also provided in conjunction with the fuel or spray nozzle valve,'that is, the opening period of the valve is'both automatic and' manually regulated. The automatic control, throughmeans of the governor-has already been described. The manual control is only emplo ed when starting, as greater quant1ties ofv uel is required.v It consists of a manually lcontrolled lever 70 pivotally mounted on top .of the cylinder head as indicated at 71. This lever is connected with a r`bellcrank through. means of a link 72. The end of the link which connects with the bellcrank 'is slotted as shown at 73 and asmatic action of the governor.

such does not interfere with the normal autoture is required in connection with the manually control to-wlt: an extensible coupling on thelink or rod 43 as indicated at 74 (see Figures lland- 2) The link or rod 42 is divided into two sections, theA uppermost section being screwed ory otherwiseconnected-.with a nut which extends into and is secured in the upper end of the coupling 74. f .The lower end of the rod projects through the coupling 74 and is slidabletherein. l

A head member is secured onthe lower section of the/rod and a 'spring'7 7 is interposed .between said head member and the lower end n40iof'the cou ling. lHence,whenstartingthe enginev an requiring aA greater quantity of fuel, it is only. necessary to pull the l'controlling lever 70 downwardly inthe direction of arrow B (see Figure 1).' Such a downward movement i-s transmitted through the link 7 2`to pull the rocker arm 40 in a `forward direction thereby placing the wedge 7 in.

a position where the opening periody of the needle valve will be increased and the quantity of fuel, injected proportlonately 1ncreased. The moment'the engine is startedthe controlling lever 70 is swung back to n ormal position and automatic regulation is then ldepended upon. The spring couplmg 74 permits such temporary forwardmovement of'4 the crank arm 40 due to the fact that` the coupling can move upwardlyfwith relation to the lower section of the rod 43. When the bellcrank is returned to normal position by returning the controlling lever to normal positiointhe head member 7 6 engages the nut 5 andthe rod will'thenfunction as a rigidv unit. It was previously stated that pressure regulatonof the fuel was one of the important Another fea-l -understood that maximum quantities of fuelL is injected during maximum engine speed'and loads and that the vquantity ofpfuel injected during reduced loads and speeds is materially decreased. Actual experience has determined that the best results are obtained as far as efliciency and good combustion `is concerned when the pressure on the fuel is increased during maximum injection of fuel and proportionately decreased during reduced inject1onof fuel. This is due to the fact that more venergy in the form of pressure is required to atomize a greater quantity of fuel and it is alsodue to the fact thatvjperfect atomization of a smallquantity vof fuel ish causes slower combustion during idling speeds which is a 'desirable feature, while more or less perfect atomization causes rapid combustion with a tendency towards pinging or knocking. Itis for this reason that .pressure regulation is maintained.

It is usually stated and commonly thought that liquids are incompressible. VIt is,'how

ever, known thatA water is compressible to a tained by' variable discharge of the metering pump. When the discharge of the pump is maintained at maximum, the greatest ressure is obtained on the eil asa greater ody of oil is forced intothepressure lines or `pipes andthe spray nozzles which have-a given or predetermined capacity. On the other hand when the discharge ofthe pump is maintained at a minimum, a smaller quantity of vnot desired when running under-slower speeds 1 or idling condltlons, ascoa'rser atomizatlon l oil is discharged in the pressure line and spray nozzle and the 'pressure will, accordingly, drop to a minimum as a smaller quantity of oil is 'delivered into a space of predetermined capacity. It is, accordingly, evident that variation in pressure is obtained due to the Variable disrirge of the pump and the compressibilityf' the oil and it is further videntthat. the pressure will be at minimum when the discharge ofthe pump is the smallest and that a maximum pressure will be obtained when the discharge of the pump is the greatest.

From the foregoing description, it will be understood that a controlling mechanism has been provided which is both manual and governor, it is possible to simultaneously vary the spraying period, the quantity of o1l injected and the pressure maintained and further that such'control may be automati- 5 cally maintained during all speed ranges between the maximum and minimum speed ofv the engine. While certain features of the present invention are more or less specifically described, I wish it understood that various changes may be resorted to within the scope of the ap- A pended claims. Similarly that the materials and finishes of the several parts employed may be such as the manufacturer may decide l or varying conditions or uses may demand.

Having thus described the invention, what I claim and desire to secure by Letters Patent is l. In a mechanical injection Diesel engine, 2o a spray nozzle, a pump adapted to deliver' fuel thereto, a valve in the spray nozzle, automatic actuated means to vary the opening period of the valve and the quantity of fuel delivered by the pump in unison, a manual control connected with the valve to vary the opening periods, a manual control on the pump to vary the quantity of fuel delivered, said manual controls being operable independent. of the automatic control and being also operable independently of each other.

- 2. In a mechanical injection Diesel engine, l a variable discharge fuel pump, a spray nozzle having a valve, means to vary `the opening period ofthe valve, a governor driven by the engine, a manual control for the governor whereby the governor m-ay be adjusted to act at any speed range between a maximum and minimum speed, and4 means actuated by the governor at maximum, minimum, or any intermediate speed whereby the quantity of fuel discharged by the pump is increased as the valve opening periodincreases sol that synchronous co-operation of the pump and valve is insured. DAVID DAVISON. l

. JUSHUA A. ROBERTS, Administrator of William Oolson, Dea

cewsed;

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