US3672343A - Centrifugal regulator system for fuel-injection combustion engines - Google Patents

Abstract

A centrifugal regulator for an internal combustion engine having a fuel injector controllable by actuation of a control rod. Movement of the governor sleeve upon a variation in rpm is transferred to a spring-biased rocker arm, which is pivoted on an intermediate lever between a fixed pivot thereof and a link connecting it with the control rod. Various types of relationship between fuel injection rate and rpm are obtained by means of differently placed adjustable or resilient stops provided on a spring-urged support arm and on which the rocker arm may swing when transferring sleeve movement to the intermediate lever and the control rod.

Description

United States Patent Biechlet al.

[ 1 June 27, 1972 [541 CENTRIFUGAL REGULATOR SYSTEM FOR FUEL-INJECTION COMBUSTION ENGINES [72] Inventors: Josef Biechl, Sindelfingen; Karl Konrath, Ludwigsburg-Hoheneck, both of Germany [30] Foreign Application Priority Data Oct. 31, 1969 Germany ..P 19 54 834.6

[52] U.S.Cl .;l23/140 MC, 123/140R 51 int. Cl ..F02d 1/04 [58] Field ofsefllch ..123/140 R, 140.3

[56] References Cited UNITED STATES PATENTS 2,818,053 12/1957 Shallenberg ..123/l40 R 3,370,579 2/1968 Nozawa ..123/14() R 3,530,845 9/1970 Staudt 1 23/1 40 R FOREIGN PATENTS OR APPLICATIONS 1,124,340 10/1956 France ..l23/140 R 1,011,223 6/1958 Germany.. ..l23/14O R 1,080,814 10/1960 Germany ..l23/140 R Primary ExaminerLaurence M. Goodridge Assistant Examiner-Ronald B. Cox Att0rneyEdwin E. Greigg [57] ABSTRACT A centrifugal regulator for an internal combustion engine having a fuel injector controllable by actuation of a control rod. Movement of the governor sleeve upon a variation in rpm is transferred to a spring-biased rocker arm, which is pivoted on an intermediate lever between a fixed pivot thereof and a link connecting it with the control rod. Various types of relationship between fuel injection rate and rpm are obtained by means of differently placed adjustable or resilient stops provided on a spring-urged support arm and on which the rocker arm may swing when transferring sleeve movement to the intermediate lever and the control rod.

5 Claims, 5 Drawing Figures PATENTEDJUNZ'I I922 SHEET 10F 4 INVENTO M j PATENTED JUN 27 I972 SHEET 2 0F 4 Fig. 2

1 PATEHTEBJUM I972 SHEET 4- BF 4 CENTRIFUGAL REGULATOR SYSTEM FOR FUEL- INJECTION COMBUSTION ENGINES FIELD OF THE INVENTION The invention relates to a centrifugal regulator for fuel-injection internal combustion engines having a govemor sleeve movable in response to the rpm of the engine.

BACKGROUND OF THE INVENTION lt is known to transfer movements of the governor sleeve of a centrifugal regulator to an intermediate lever which is movable about a fixed pivot and coupled to a movable control member of the injection pump for controlling the rate of fuel supply, a counterforce means being provided for subjecting the governor sleeve to a counteracting spring force.

Fuel-injection engines, particularly those of motor vehicles, operate in a wide range of rpm s. The injector pumps are often provided with regulators serving not only to control the rpm but also to vary the maximum full-load rate of fuel supply within as large a range of rpms as possible in accordance with what is required by the engine for smokeless combustion or for a predetermined type of variation or adaptation of the rate of supply according to particular operating conditions.

Known centrifugal regulators of the above-indicated type, such as are described in German Pat. Nos. 1,011,223 and 1,080,814, provide adaptation of the amount of fuel supplied by the injector pump to the full-load operating characteristic of the engine, by means of an adaptor comprising a spring device inserted between the counterforce means and the governor sleeve. In operation, upon an increasein rpm, the spring displaces the control rod of the fuel-injector pump in the direction towards stop" according to the bias and the stiffness thereof. This reduces the rate of supply by a predetermined amount.

This arrangement has the disadvantage that the maximum rate of supply in response to an increase in rpm can only be controlleddownwards, whereas a rising or a composite type of variation, i.e. where the rate of supply first increases and then decreases, or vice versa, cannot be realized with the known arrangement.

Arrangements are known per se in other types of regulators than the one referred to for obtaining an arbitrary type of variation of a rate of supply, for instance, by means of a cam (U.S. Pat. No. 2,259,693 and German Pat. No. 1,010,321). However, these arrangements are not applicable to the type of regulators initially referred to.

OBJECT AND SUMMARY OF THE INVENTION It is an object of the invention to provide in a centrifugal regulator of the type initially referred to an arrangement which enables a control of the variation of the rate of supply of the injector pump, by which for varying rpm's the maximum rate of supply can be variable within a predetermined range of rpm's by a desired amount in either sense, the sense of the variation being reversible at least once within the range of rpms.

The essential features of the invention comprise a rocker arm coupled between the governor sleeve and the intermediate lever and having at least two stop surfaces cooperating with corresponding stops on the counterforce means, at least one of the stops being resilient, and either one thereof serving as a pivot point for rocking movements of the rocker arm, the rocker arm being pivoted at one end to the intermediate.

In an embodiment of the invention, the rocker arm is pivoted to the intermediate lever between its point of coupling with the control rod and the fixed pivot.

In a further embodiment, a resilient stop is positioned in the prolongation of the axis of the governor sleeve and a second fixed stop is provided above the first one and is adjustable by means of a screw to a desired level. With this arrangement, it is possible to control the full-load rate of supply to cause it to increase or decrease with an increase in rpm, or to first decrease and then increase again within a higher range of rpms.

However, if it is desired to control the full-load rate of supply in response to an increase in rpm so as to first increase and then decrease, according to a further embodiment, a first resilient stop is provided in the prolongation of the axis of the governor sleeve and a second resilient stop is arranged above the first one between the axis of the control member and the pivoted end of the rocker arm, a third, adjustable fixed stop being provided below the first one.

In a still further embodiment of the invention, the rocker arm has a pair of stop surfaces provided above and below the axis of the governor sleeve and cooperating with correspondingly positioned stops. With this arrangement, any desired type of adaptation of the variation of the rate of supply to different engine operating characteristics can be realized.

The invention will be described in detail with reference to the drawing.

BRIEF DESCRIPTION OF THE DRAWING and FIGS. 4 and 5 are diagrams illustrating the operation of the invention.

DESCRIPTION OF EMBODIMENTS In the FIG. 1 embodiment, 10 designates the cam shaft of the fuel injection pump (not shown) of an internal combustion engine having a carrier member 11, on which centrifugal weights 12 are pivotally mounted in a manner known per se. Arms 13 on the weights engage the contact surface 14 of a governor member or sleeve 15 slidable on shaft 10 with its boring 16. The other end face 20 of sleeve 15 engages a roller 21 mounted indirectly on an intermediate lever 22, which is pivoted on a pin 26 afiixed to the housing 15 of the regulator. Roller 21 is directly mounted on a rocker arm 27, which is pivotally mounted on lever 22 by means of a pin 28 and is urged in its inoperative position into engagement with a stop pin 30 on lever 22 by a spring 29. Lever 22 is coupled via link 31 with a fuel supply control member in the form of a control rod 32 of the fuel injector pump. A tension spring 35 is attached at one end to lever 22 and serves to eliminate play and also urges rod 32 towards higher fuel supply, thereby serving as a starting spring.

Pivoting movement of arm 27 away from the inoperative position takes place against the return force of a spring 29 and is limited by a stop 33 on lever 22, which prevents the engine from racing if spring 29 breaks off. In fact, in the absence of spring 29, starting spring 35 would pull lever 22 to increase the supply rate. Stop 33 is positioned so as to permit arm 27 to turn as much as is necessary for adjusting the rate of supply. The function of this angular deflection is described in more detail below.

Pivotally mounted on pin 26 is also counterforce means in the form of a support arm 37, which transmits to governor sleeve 15 a counteracting spring force of a speed control spring 38. Spring 38 is a tension spring having one end thereof attached to lever 37 and the other end to a rocking lever 39, which is fixedly mounted on a shaft 40 journaled in housing 25. Lever 39 is coupled by shaft 40 to a handle 41 placed outside the housing and shown in its terminal position, which is defined by a screw 42 and serves to determine the maximum rpm obtained by the regulator. The position of support ann 37 in response to the bias of spring 38 is determined by an adjusting screw 43. This determines the point of attachment 44 of spring 38 and also, as will be explained below, the full-load initial position of control rod 32.

An additional adjustable idling control spring 45 provided in housing 25 extends through a recess 46 in support arm 37 and influences the movements of intermediate lever 22 in the idling control range by engagement with a surface 47 on rocker arm 27.

Support arm 37 has a pair of stops 49, 51 adjusted to project therefrom by amounts a and b respectively. Stop 49 is provided by a screw 50 with a lock nut 52 thereon and cooperates with a stop surface 53 of arm 27. Stop 51 is located in the prolongation of cam shaft and comprises a bolt 55 and a spring 56 providing a resilient stop 51 cooperating with a stop surface 57 fonned by the periphery of roller 21.

The projection distances a and b and the biasing force of stop 51, as well as the operating range of idling control spring 45, can be adjusted through an opening 59in housing 25, having a lid 58 provided therefor.

The distance a is adjusted by turning of screw 50 and locking the same with nut 52. The distance b can be adjusted by interposing a disc 54 of suitable thickness. As an altemative, stop 51 could be mounted in a manner known per se, not shown, in a threaded sleeve which would be adjustable in support arm 37 and be locked in adjusted position by a lock nut.

FIG. 2 shows the second embodiment, which is substantially similar to that of FIG. 1, as indicated by identical reference numerals, the differences relative to FIG. 1 being as follows: Support arm 37, besides resilient stop 51, has instead of the fixed stop 49 of the first embodiment, a second resilient stop 60 similar to stop 51 and comprising a stop bolt 61 and a spring 62. Below the axis of cam shaft 10 and stop 51, a third, fixed stop 63 is provided by a screw 65 locked by means of a nut 64. Stop 63 cooperates with a stop surface 66 on rocker arm 27'. Stops 51, 60 and 63 are adjusted to project by distances b, d and e respectively.

FIG. 3 shows the third embodiment, which differs in the following respects from the foregoing ones: Support arm 37" is mounted on a separate pin 70 in the upper part of housing 25", whereas intermediate lever 22", similarly to lever 22 of FIGS. 1 and 2, is pivoted on pivot 26 in the lower part of the housing. A further difference relative to FIGS. 1 and 2 is that rocker arm 27" is linked not only to intermediate lever 22" but also through a bolt 71 to governor sleeve A slot 72 in the lower end of lever 22" in engagement with pin 26 makes it possible for lever 22" to perform small vertical movements, for instance, when rocker arm 27" rocks on bolt 71. Arm 27 has a pair of contact surfaces 75, 76, one above and the other below the axis of cam shaft 10. Opposed to contact surfaces 75 and 76 are stops 77 and 78, respectively, of arm 22".

DESCRIPTION OF OPERATION The three embodiments according to FIGS. 1, 2 and 3 make it possible to adapt the full-load fuel supply of the injector pump in response to rpm to the maximum fuel supply rate required for smokeless combustion or for some other operating condition ofthe engine.

For adapting the full-load rate ofsupply, by way of example, the following control processes can be realized by the regulator:

I. The rate of supply decreases with increasing rpm, i.e., the

control rod is displaced towards stop" by a predetermined amount within a certain range of rpm,

II. The rate ofsupply increases with increasing rpm,

III. The rate of supply first decreases and then increases with increasing rpm, and

IV. The rate of supply first increases and then decreases with increasing rpm.

These four possible control processes are illustrated in the diagrams of FIGS. 4 and 5, in which the abscissa is the rpm designated n and the ordinate is the rate of supply 0 or the position coordinate R of the control rod. It is assumed that the coordinate R is a measure of the rate of supply Q of the injector pump. If this is true, the corresponding graphs show the rate of supply as a function of the rpm. Process I is represented in FIG. 4 by the heavy line AB, process II by C-D, process III in FIG. 5 by DEF and process IV by D-G-F. The dash lines H-K-D and H-K-A, I-I-K-L or H-KC show the variation of the control rod coordinate in the lower range of rpm, when the regulator controls an excess fuel amount required for starting. When no excess starting fuel is needed, the control rod follows, for instance, line M-A (FIG. 4).

The measure of section H-K is determined by the bias of starting spring 35.

If the regulator does not perform any adapting process, the variation takes place, for instance, along the line HK[r-B of FIG. 4. The downward control curve for limiting the maximum rpm is designated in FIGS. 4 and 5 by 8-? and F-P, respectively.

The operation of the regulator will be described with particular emphasis on the adapting function provided by the cooperation of rocker arm 27, 27', 27" and stops 49, 51, 60, 63, 77 and 78.

In FIG. 1, weights 12 are shown in the inoperative position, handle 41 rests on stop 42, and control spring 38 is biased for limiting the maximum rpm via rocking lever 39. The force of spring 38 holds support arm 37 in position against the head 43a of adjustment screw 43. Starting spring 35, by means of intermediate lever 22 and link 31, holds control rod 32 into the position in which the injector pump supplies the maximum amount of fuel required for starting the engine (H in FIGS. 4 and 5). If the engine starts running at n1 rpm, weights l2 push sleeve 15 and roller 21 to the position in which the latter engages end surface 51a of stop 51. Sleeve 15 and roller 21 have then been displaced by an amount 0 and control rod 32 is, for instance, at the point C of FIG. 4. Since roller 21 and rocker arm 27 are coupled by spring 29 and stop 30 with intermediate lever 22, any movement of roller 21 in response to governor sleeve 15 is transferred in a measure corresponding to the lever arm ratio to control rod 32.

If the regulator is to realize the control process II (increasing rate of supply), stop 49 is adjusted to such a value of distance a that it just touches stop surface 53 of rocker arm 27 when the distance 0 has been traversed. If the rpm rises beyond n1, the sleeve force overcomes the bias of spring 56 of stop 51, stop bolt 55 is displaced to the right and the distance b is reduced. Simultaneously the increasing sleeve force also overcomes the force of spring 29 and rocker arm 27 rocks about the momentary pivoting point formed by stop surface 53 and fixed stop 50. Since rocker arm 27 is hinged by pin 28 to lever 22 at a higher level than contact surfaces 53, 57, pin 28 will move towards the left and control rod 32 will be displaced in a direction corresponding to an increased rate of supply (graphs C-B of FIG. 4).

By using a softer spring 56 with a stronger bias it is also possible with the arrangement of the stop just described to realize a control process according to CS-TB in FIG. 4.

If a control process according to I (decreasing rate of supply) is to be realized, stop 49 is removed or is set back in an inoperative position. After this, only stop surface 57 and stop 51 are active and the sleeve force can compress stop 51 by an amount corresponding to the distance b Rocker arm 27 then remains relative to intermediate lever 22 in the position shown, lever 22 participates in the movement of roller 27 and the rate of supply decreases according to the graph A-B of FIG. 4.

To realize the process III (first decreasing, then increasing), the distance a of stop 49 is adjusted so as to cause first a portion of the distance b to be traversed until surface 53 hits stop 49, after which the rest of distance b is covered simultaneously with the rocking movement by rocker arm 27 about its point of contact with stop 49. This process is in accordance with line D-E-F of FIG. 5.

The process IV (see line D-G-F in FIG. 5) is achieved with the regulator according to FIG. 2. The projection distances b and d of stops 51 and 60 are adjusted in such a way that when the excess fuel quantity for starting has been used up (K-D in FIG. 5) or at the end of the distance c, stop surfaces 53 and 57 simultaneously engage stops 51 and 60. Between fixed stop 63 and stop surface 66, however, there remains a spacing corresponding to the difference between distance f and that corresponding to the traversed length c. Furthermore, the bias of spring 56 is weaker than that of spring 62. If the rpm surpasses the value n1, spring 56 will first give way, stop 60 will operate as a fixed stop, rocker arm 27' rocks on the momentary pivot point formed by stop 60, and the rate of supply is increased (D-G). When the maximum allowable full-load quantity is reached at point G in FIG. 5, corresponding to an rpm of n3, rocker arm 27 has traversed the distance f and stop surface 66 strikes against stop 63. Upon a further increase in rpm, sleeve works against both of the resilient stops 51 and 60 and rocker arm 27 now rocks on stop 63, after which the rate of supply decreases. At the terminal value n2 (point F in FIG. 5), the adapting process is completed.

With the embodiment of FIG. 3, it is possible to realize all of the processes l-IV.

In a process according to A-B of FIG. 4 (process I), the upper stop 77 recedes resiliently (spring displacement h) and the lower stop 78 is a fixed pivot point. In this case it may have a very strong bias and be blocked or be replaced by a fixed bolt.

A process according to C-B of FIG. 4 (process II) can be realized if the stop 78 recedes (spring displacement g) and the stop 77 operates as a fixed pivot point.

The regulator realizes a process according to the broken graph D-E-F of FIG. 5 (process III) if, between the rpm values n1 and n3, first stop 77 recedes by an amount h and then, between n3 and n2, stop 78 by an amount g.

A variation of the rate of supply according to the kinked graph D-G-F of FIG. 5 process IV) is realized if the resilient stops 77 and 78 operate in the opposite order to the one just described, stop 78 receding first and then stop 77.

Through the use of two springs instead of each one of springs 56, 62 in resilient stops 51, 60, 77, 78, it is possible to further adapt the control process.

The regulator, in all cases described above, effects a downward control upon reaching the final rpm value n2, when the sleeve force surpasses the bias of control spring 38 and support arm 37, 37" moves away from screw head 43a. This receding movement is followed by intermediate lever 22, 22",

which is driven by rocker arm 27, 27', 27", as the latter is held in engagement with support arm 37, and intermediate lever 22, 22" pulls control rod 32 into the stop" position (line B-P of FIG. 4 or F-P of FIG. 5).

That which is claimed is:

l. A centrifugal rpm regulator system for internal combustion engines operating on injected fuel, said system being of theknown type that has (a) a governor member movable as a function of the engine rpm, (b) a fuel injection pump having a movable control member for controlling the rate of fuel supply, (c) an intermediate lever movable about a fixed pivot for transferring the displacements of said governor member to said control member, (d) at least one counteracting spring and (e) a force transmitting member subjecting said governor member to the force of said counteracting spring, the improvement comprising,

A. a rocker arm in engagement with said governor member and pivotally attached at one of its ends to said intermediate lever at a location remote from said fixed pivot, said rocker arm constituting the sole means to transfer the motions of said governor member to said intermediate lever,

B. at least two stop surfaces provided on said rocker arm remote from said pivotally attached end thereof, and

C. at least two stops provided on said force transmitting member for cooperating, upon movement of said governor member, with corresponding stop surfaces provided on said rocker arm, at least one of said stops yielding resiliently and another of said stops being stationary to serve as a fixed point for said rocker arm during pivotal motions thereof.

2. An improvement to claim 1, in which said rocker arm is pivoted to said intermediate lever between the point of coupling thereof to said control member and said fixed pivot.

3. An improvement according to claim 1, in which said governor member is axially movable, said resilient stop is positioned in the prolongation of the axis of said governor member and a second one of said stops is adjustable to an arbitrary fixed level.

4. An improvement according to claim 1, in which said governor member is axially movable, said stops include a first resilient stop positioned in the prolongation of the axis of said governor member, a second resilient stop between said axis and said pivoted end of said rocker member, and a third stop adjustable at an arbitrary fixed level and positioned at the opposite side of said second resilient stop relative to said first resilient stop.

5. An improvement according to claim 1, in which said governor member is axially movable, said stop surfaces are two in number and are positioned at opposite sides of the axis of said governor member for cooperation with correspondingly positioned stops.

Claims (5)

1. A centrifugal rpm regulator system for internal combustion engines operating on injected fuel, said system being of the known type that has (a) a governor member movable as a function of the engine rpm, (b) a fuel injection pump having a movable control member for controlling the rate of fuel supply, (c) an intermediate lever movable about a fixed pivot for transferring the displacements of said governor member to said control member, (d) at least one counteracting spring and (e) a force transmitting member subjecting said governor member to the force of said counteracting spring, the improvement comprising, A. a rocker arm in engagement with said governor member and pivotally attached at one of its ends to said intermediate lever at a location remote from said fixed pivot, said rocker arm constituting the sole means to transfer the motions of said governor member to said intermediate lever, B. at least two stop surfaces provided on said rocker arm remote from said pivotally attached end thereof, and C. at least two stops provided on said force transmitting member for cooperating, upon movement of said governor member, with corresponding stop surfaces provided on said rocker arm, at least one of said stops yielding resiliently and another of said stops being stationary to serve as a fixed point for said rocker arm during pivotal motions thereof.

2. An improvement to claim 1, in which said rocker arm is pivoted to said intermediate lever between the point of coupling thereof to said control member and said fixed pivot.

3. An improvement according to claim 1, in which said governor member is axially movable, said resilient stop is positioned in the prolongation of the axis of said governor member and a second one of said stops is adjustable to an arbitrary fixed level.

4. An improvement according to claim 1, in which said governor member is axially movable, said stops include a first resilient stop positioned in the prolongation of the axis of said governor member, a second resilient stop between said axis and said pivoted end of said rocker member, and a third stop adjustable at an arbitrary fixed level and positioned at the opposite side of said second resilient stop relative to said first resilient stop.

5. An improvement according to claim 1, in which said governor member is axially movable, said stop surfaces are two in number and are positioned at opposite sides of the axis of said governor member for cooperation with correspondingly positioned stops.

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