US2715890A - Centrifugal governor, especially for the regulation of the instant of injection in combustion engines - Google Patents

Description

Aug. 23, 1

955 o. SCHILLING 2,715,390

CENTRIFUGAL GOVERNOR, ESPECIALLY FOR THE REGULATION OF THE INSTANT OF INJECTION IN COMBUSTION ENGINES Filed April 22, 1952 /n van for United States Patent G i CENTRIFUGAL GDVERNOR, ESPECIALLY FOR THE REGULATTON OF THE INSTANT OF INJECTION TN COMBUSTION ENGINES Otto Schilling, Stuttgart-Unterturkheim, Germany, assignor to Daimler-Benz Airtiengeseiischaft, Stuttgart- Unterturkheim, Germany Application April 22, 1952, Serial No. 283,633

Claims priority, application Germany, April 23, 1951 7 Ciaims. (Cl. 121-42) The present invention relates to a centrifugal governor, especially for regulating the instant of injection in combustion engines.

It is customary to shift the instant or moment of injection or ignition in combustion engines in dependence on the number of revolutions by means of a centrifugal governor, in such a manner that with an increasing number of revolutions the camshaft of the injection pump or the shaft of the ignition distributor is displaced rela tive to the crankshaft of the engine in the sense of advancing the instant of injection or ignition. This is eii'ected, for example, by means of helical splines and grooves, which couple with each other a gear part, connected with the crankshaft, and a gear part, connected with the shaft of the injection pump or of the ignition distributor.

Accordingly, it is an object of the present invention to provide a construction which is suitable for these purposes and which distinguishes itself by the small amount of space occupied thereby and by as small as possible a weight.

it is another object of the present invention to provide such a construction which guarantees exact and reliable regulation of the instant of the fuel injection or ignition over the entire speed range of the engine.

Accordingly, a desirable characteristic of the present invention resides in the fact that the centrifugal weights displace a distributing slide valve, thereby providing a hydraulic auxiliary force against the action of a spring.

The auxiliary force in turn produces the displacement of a piston relative to a cylinder, and thereby effects the regulations in such a manner that for each position of the distributing slide valve, i. e., for each number of revolutions of the engine, a certain corresponding relative position of piston and cylinder results, to which a certain shift of the instant of injection or ignition at an earlier or later moment is correlated.

According to a further characteristic of the present invention the movable part of the piston and cylinder assembly is provided with arms which project into openings in the flyweight carrier with play in a circumferential direction, whereby a particularly compact construction of the governor may be achieved.

A further characteristic of the present invention relates to the fact that the springs, which act in opposition to the movement of the movable part of the piston and cylinder assembly, simultaneously assume the task of the springs for the governor relief valves.

Further objects, advantages and features of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows for purposes of illus tration only one preferred embodiment in accordance with the present invention, and wherein Fig. 1 is a cross-sectional view taken along line 1-1 of Fig. 2,

Fig. 2 is a cross-sectional view taken along line 2-2 of Fig. l,

Fig. 3 is a cross-sectional view taken along line 33 of Fig. 2, and

Fig. 4 shows a diagram of the deflection of the regulating springs.

Referring now more particularly to the drawing wherein like reference numerals are used throughout the various views to desi nate like parts, reference numeral 14) designates the casing of a combustion engine, for example, of a diesel engine. The valve control shaft 11, which is supported in the casing 19, is driven from the crankshaft of the engine over a gear wheel 12, and is retained in the axial direction by a thrust washer or collar 13.

The hub 15 and the fly-weight carrier 16 are firmly connected with the shaft 11 and with the gear wheel 12, respectively. The ily-weight carrier 16 includes for that purpose two arms or flanges 1'7 and 18, as shown particularly in Fig. 2, which arms or flanges extend over a part of the circumference in the axial direction and are connected to the flange 19 of the hub 15 at diametricaily opposite points.

Furthermore, as shown in Pig. 3, provision is made for screws 2% to connect together the two parts 15 and 16 by means of their flanges 19, 18 which permits assembly of the control device as a unit outside the engine, and which for installation in the engine thereupon requires only fastening thereof as a whole to the gear wheel 12 or to the shaft 11 by means of the bolts 14.

The part 22 is inserted into the hub 15 by means of journal 21, and is supported in the hub 15 by means of friction bearings 23 and 24. The part 22 is also coupled or connected with the hub 15 by means of helical splines or grooves 25 so that any relative rotational movement between these two parts is always accompanied also by relative axial displacement.

The part 22 is provided with two arms or flanges 22' and 22" which are radially directed toward the outside, and which, as appears particularly from Fig. 2, extend substantially perpendicularly to the arms 17 and 18 of the iiy-weight carrier 16, in such a manner that they protrude to the outside through the iuterspaces, which are formed between the arms 17 and 18, whereby a play exists in the circumferential direction in the amount of xi and x2 in the one or the other direction of rotation.

A ring gear 26 is flanged to the arms of flanges 22 and 22" which ring gear is connected therewith by means of screws and which drives one or several fuel injection pumps of the engine by means of suitable gears (not shown in the drawing).

The hub of the part 22 is extended by a cylindrical part 27 on the side opposite the journal 21, which cylindrical part is supported, on the one hand, in the flyweight carrier 16, and, on the other hand, encircles a distributing slide valve 28, which is supported therein. The fly-weights 30 are supported in the fly-weight carrier by means of journals 29 in such a manner that they can move outwardly towards the outside under the effect of the centrifugal force, and thereby displace the slide valve 28 axially by means of the arms 31 against the effect of the regulating spring 33 which is supported in the flyweight carrier against the screw plug 32.

The part 22 is further provided with a ring-shaped cylindrical attachment 34 which serves as outside cylinder for the piston part 35, formed integrally with the hub 15. A piston space 36 is formed between the piston part and the cylinder part 34. One or several control slots 37 are milled into the hub part of the member 22, which are controlled by the edges of the collar 38 pro vided at the distributing slide valve 28, in such a manner that the control openings 37 are connected with an inlet space 39 during movement of the distributing slide valve to the right, and with an outlet space 40 during movement of the distributing slide valve 28 to the left. The

the delivery pipe 42, for example, through a pump (not illustrated) which is driven by the engine. The outlet space 40 is connected in a suitable manner with the interior of the casing or with the suction pipe of the pump or with the oil reservoir by appropriate openings, pipes, or the like. 7 r I On the side oppositethe piston space 36 the cylinder part 22 is furthermore spring-loaded, for example, by two' springs 43,'which are supported, on the one hand, against the fly-weight carrier 16, and, on the other hand, against the part 22 by insertion of the guide piece 44. The guide pieces '44 thereby serve simultaneously as pressure relief valves for closing the bores 45 in the part 22.

Operation 7 .The mode of operation of the above described centrifugal governor is as follows:

In the position shown in the drawing the engine runs,

7 forv example, at a relatively small number of revolutions corresponding to idling thereof, whereby the fly-weights 30 take their normal rest positions and the distributing slide valve 28 is in its left end position. With an increase in the number of revolutions of the engine the fly-weights 30 swing outwardly whereby the distributing 'ment to the right of the journal 21 so that by the interact-ion of the helical splines and grooves it must simultaneously undergo a certain relative rotational movement depending on the pitch -of the screw head of the helical splines in the hub part 15. As a result of this relative-rotational movement, the shaft which is driven by the gearwheel 26 and which controls the injection or the ignitionof the fuel is advanced with respect to the valve gear shaft or the 'crankshaft'so that an appropriate earlier or advanced injection or earlier or advanced ignition of the fuel'takes place.

It is possible by appropriately selecting the regulating spring 33 to provide a continuous adjustment of the timing of the injection or of the ignition, over the entire speed range of the engine, as may be seen, for example, from the diagram of Fig. 4. The moment of injection is 'the'reby advanced from about 20 prior to upper dead center during idling to about 40 with the maximum number of revolution within the range which is determined by the play x1 and x2. I

.When the number of revolutions again decreases so that the fly we'ights 30 move again inwardly, the distributing slide valve 28 is thereby displaced to the left relative to the cylinder part 22. The oil under pressure can consequently flow from the piston space 36 overthe control slot 37- into the-outlet space 40. V The cylinder 22 is thereby displaced to the-left under the effect of the springs 43 until such time as the control openings37- are again closed by the control edges 38 of the distributing slide valve 28 whereupon a new condi tion :of equilibrium exists which corresponds to the existing number-of revolutions. V

If, for example, during maximum number of revolu tions the pressure in space 36 increases beyond the permissible maximum amount, the pressurizedoil may flow to. the outside through bores 45 since the guide piece 44 for the spring 43 simultaneously serves as a safety valve.

In the illustrated embodiment the regulator is inserted as a 'pre-assembled unit into the end of the valve control vided in the casing by means of a longitudinal bore 41 in the journal 21. Oil under pressure is supplied to shaft 11 by means of the hub piece 15 and fastened to the gear 12 by bolts 14.- The injection pump or pumps are thereby driven by gear 26.

It is, however, withinthe scope of the present invention to provide also an arrangement in such a manner that the governor aggregate is arranged co-axially with the pump control shaft, or is arranged directly on the pump control shaft.

The present inventionis applicable to all types of combustion engines, including carburetor engines and other engines, although it is of particular importance for diesel engines.

What I claim is: I

l. A centrifugal governor comprising a rotary driving member, a hub-shaped part flanged to the latter, a ring piston part connected with this part, a carrier member with means, through which the same is connected with the driving member and the mentioned hub-shaped part,

fly weights, which'are. supported at the carrier member, a slide-valve member, adapted to 'be axially adjusted by the fly weights, a sleeve member, which is arranged con centrically to the slide valve member, with a cylinder part, which is concentrical' to the mentioned ring piston part, a cylinder bottom, which connects the cylinder part with the other sleeve member, and a journal-shaped part concentrically to the mentioned hub-shaped part, whereby the sleeve member is adjustable both relatively to the hub-shaped part and relatively to the slide-valve member, means at the hub-shaped part and at the sleeve-I shaped part, adapted to twist the latter relatively to the first one, when the huh-shaped part is axially dis-- placed, elastic means, which support the slide valve mem ber against the effect of the fly weights, means for sup ply of a pressure means to the interior. of the mentioned cylinder part, control means at the ,slide member and at the sleeve-shaped part, adaptedto control the pres- 7 sure means in such a manner that at axial displacement of the slide member also the mentioned hub-shaped part is axially displaced, openings in the mentioned cylinder bottom, spring means, which act against the motion of the sleeve-shaped part under the eflect of the pressure means, and abutting members betweenthese elastic means and the cylinder bottom, which close the mentioned openings under the spring pressure of the spring means, in such a manner that at a certain pressure of V the pressure means the mentioned abutting members release the openings.

2. A centrifugal governor according to claim 1,

wherein the carrier member, which carries the fly weights, is arranged con-axially to the slide-valve mem:

ber, the sleeve-shaped member'andthe driving member, the elastic means, which act on the slide-valve member, is provided'as a spring, which is centrally arranged in the carrier member, and the spring means, which .act on the sleeve-shaped part, are provided as several springs, which are distribntedon the circumference;

3. A centrifugal governor according to claim '1,

wherein the carrier member is provided with arms, by

means of which it is connected with the mentioned hubshape'd part and the driving member, the sleeve-shaped part between the huh-shaped part is arranged between,

the hub-shaped part and the carrier member and arrangedwith radial arms, which protrude towards the out- A side through the space between the arms of the carrier member with play in circumferential direction, and means at the ends of the arms outside the carrier member, adapted for conveyance of the drive. V

4. A centrifugal governor comprising a rotary driving. member, a carrier connected with said driving member,

fly-weights supported in'said carrier, spring means for returning said fiy-weights to their normal rest position, w,

an axially adjustable sliding member, flange means on said carrier for supporting said fly-weights and for conmeeting said carrier with said driving-member, said flange means being provided with interspaces, flange means on said sliding member extending outwardly through said interspaces with play in the circumferential direction, a cylinder connected with said sliding member and a piston in said cylinder, said piston being connected with said driving member and said cylinder being axially adjustable with respect thereto, control means in said sliding member, means for conducting a hydraulic medium through said control means into the inside of said cylinder, said sliding member being moved axially under the efiect of pressure by said medium, helical spline and groove means between said driving member and said sliding member for simultaneously imparting rotational movement to said sliding member relative to said driving member, and means on said sliding member for transmitting the drive.

5. A centrifugal governor according to claim 4, wherein said driving member is formed as a gear, and wherein said means for transmitting the drive includes a gear connecting the ends of the flange means on said sliding member.

6. A centrifugal governor according to claim 4, further comprising means for securely connecting the carrier for said fiy-weights with a part connected with said driving member, and means independent of the lastmentioned means for securely connecting said carrier and said last-mentioned part to said driving member.

7. A centrifugal governor comprising a rotary driving member, a carrier connected with said driving member, fly-weights supported in said carrier, spring means for returning said fly-weights to their normal rest position, 30

an axially adjustable sliding member, a cylinder connected with said sliding member and a piston in said cylinder, said piston being connected with said driving member and said cylinder being axially adjustable with respect thereto, control means in said sliding member, means for conducting a hydraulic medium through said control means into the inside of said cylinder, said sliding member being moved axially under the effect of pressure by said medium, spring means operative to oppose movement of said axially adjustable sliding member, axial openings in said sliding member, intermediate members between said last-mentioned spring means and said sliding member for covering said axial openings and for opening said axial openings under predetermined pressure of said medium in said cylinder, means between said sliding member and said driving member for simultaneously imparting rotational movement to said sliding member during axial movement thereof, and means on said sliding member for transmitting the drive.

References Cited in the file of this patent UNITED STATES PATENTS 243,450 Lafargue June 28, 1881 1,130,177 Kramer Mar. 2, 1915 2,204,649 Barnhart June 18, 1940 2,578,350 Greene Dec. 11, 1951 FOREIGN PATENTS 153,740 Austria July 11, 1938

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