Centrifugal R.p.m. Regulator For Internal Combustion Engines

Abstract

In a centrifugal r.p.m. regulator for internal combustion engines, the governor sleeve is connected to a fuel quantity control member through a linkage assembly that includes an intermediate lever coupled to a manually operable lever to arbitrarily adjust said fuel quantity control member. The r.p.m. regulator includes a spring-loaded support arm against which the governor sleeve is adapted to abut after traveling a predetermined distance under the force exerted by the centrifugal weights as the engine r.p.m. increases. Beyond a predetermined r.p.m. the last-named force overcomes the force of the support lever spring thus permitting the governor sleeve to be further displaced, shifting thereby said control member to lessen the injected fuel quantities.

Description

BACKGROUND OF THE INVENTION

This invention relates to a centrifugal governor device for regulating the r.p.m. of internal combustion engines. The device is of the type that includes an intermediate lever connected at one end to a governor sleeve displaceable as a function of the r.p.m. and attached at the other end to a fuel quantity control member of a fuel injection pump. The intermediate lever is also movable by an externally operable regulator link connected to said intermediate lever and serving for an arbitrary adjustment of said fuel quantity control member. For motions of the governor sleeve, the intermediate lever pivots about its coupling with the regulator link and for motions of the regulator link, the intermediate lever pivots about its coupling with the governor sleeve.

An r,p.m. regulator of the aforenoted type is described in German Pat. No. 900,507 wherein, as a function of the position of the governor sleeve and of the position of the regulator link engaging the intermediate lever, the fuel quantity control rod of a fuel injection pump is set, determining thereby the fuel quantities for the starting, idling or "full-load" operation of the internal combustion engine. Further, the r.p.m. is determined by the arrangement, preload and characteristics of the regulator springs disposed in the governor weights. If the r.p.m. changes, the centrifugal governor automatically varies the injected fuel quantities arbitrarily set by the aforenoted regulator link. Such arrangements ensure that there are no significant resetting forces exerted on the regulator link and thus on the bellcranklike manual-operating lever connected therewith.

It is, however, a disadvantage of arrangements of the afore-outlined type that in the operational range of the regulator, a relatively large number of spring combinations is needed for the regulation of r.p.m.s and fuel quantities associated therewith. As a consequence, an adaptation of the regulator device to changed operational conditions or to different internal combustion engines is difficult and costly.

OBJECT AND SUMMARY OF THE INVENTION

It is an object of the invention to provide an improved centrifugal r.p.m. regulator wherein the aforenoted plural spring combinations may be omitted without losing the advantages of known linkage assemblies that are free from resetting forces.

According to the invention, the governor sleeve abuts, subsequent to a certain displacement in opposition to the force of an idler spring, against a support lever which is in engagement with an adjustable stop and which is pivotable about a stationary pin and is exposed to a regulator leaf spring, the force and effective length of which is adjustable.

The invention will be better understood, as well as further objects and advantages will become more apparent from the ensuing detailed specification of a preferred, although exemplary embodiment taken in conjunction with the sole FIGURE illustrating the invention in longitudinal section.

DESCRIPTION OF THE PREFERRED EMBODIMENT

To the drive shaft 1 of a fuel injection pump associated with an internal combustion engine (neither shown) there is fixedly secured a faceplate 2 on which there are pivotally mounted centrifugal weights 3. The ends of radially inwardly extending arms 4 of the weights 3 engage the frontal face 5' of a roller bearing 5 which is slidably and relatively rotatably mounted on a stub 1' of the drive shaft 1. The roller bearing 5 transmits the setting forces of the centrifugal weights 3 to a governor sleeve 6 slidably mounted on the stub 1' and in engagement with roller bearing 5. The axial displacements of the governor sleeve 6 are transmitted by means of shift lever 7, an intermediate lever 8, a guide rod 9 and an arm 10 to a fuel delivery control rod 11 of the fuel injection pump. The shift lever 7 is pivotally secured to housing 12 by a pin 13.

The shift lever 7, by means of a pin 14 fixedly secured to one end, is pivotally held in a fork 15 formed at the terminus of a bolt 16 passing radially through, and fixedly held in, the governor sleeve 6. At its other end, the shift lever 7 is pivotally secured to a terminus of the intermediate lever 8 which is provided along a portion of its length with a guide slot 17.

An adjusting link 19 forms a bell crank with an externally operable adjusting lever 21 and is, on the one hand, pivotally secured to housing 12 by means of a pin 20, and, on the other hand, is connected to intermediate lever 8 by means of a pin 18 affixed to one end of regulator link 19 and extending into guide slot 17.

The guide rod 9 which is pivotally attached to the intermediate lever 8 at one end and which carries an accumulator 22 at the other end, transmits the setting forces exerted by the governor sleeve 6 and the regulator link 19 to an arm 10 affixed to the fuel quantity control rod 11. Should the latter, at the end of its travel in either of two possible directions, abut against a stop, the spring 23 of the accumulator 22, in case of continuing setting forces, is compressed from one or the other direction. The preload of spring 23 is so designed that it overcomes at least the frictional forces generated in the r.p.m. regulator and in the fuel injection pump.

In the frontal face 24 of the governor sleeve 6, remote from the roller bearing 5, there is provided an axial depression 25 in which nests one end of an idler coil spring 26. The latter extends through an opening 27 provided in a support lever 28 and engages, with its other end, a spring seat disc 29' secured to an adjusting screw 29 which is held in a twice-bent terminal portion 30 of the support lever 28. The free end face of the adjusting screw 29 is provided with a radial slot 31 adapted to receive an adjusting tool such as a screwdriver. The adjusting screw 29 may be immobilized in any position by means of a securing nut 32.

The support lever 28 is pivotally held by a pin 33, which, in turn, is fixedly secured to housing 12. Pin 33 also serves as a pivotal support for a regulator leaf spring 34 and a bellcrank lever 35. The former engages, with its terminus remote from the pin 33, a forklike end portion 36 of the support lever 28. Said forklike end portion 36, in turn, engages a radial pin 37 rigidly secured to a head 40' of a support bolt 40 provided with a longitudinal groove 38. The support bolt 40 is slidably held in a bore of a projection 41 of the housing 12 and is prevented from rotating by a pin 39 held in projection 41 and extending into groove 38 of support bolt 40. Between the head 40' of support bolt 40 and an upstanding face of projection 41 there is disposed, in a preloaded condition, a coil spring 43 urging the support bolt 40 outwardly of the bore of projection 41. A nut 42, threadedly received by support bolt 40 and abutting against an opposed upstanding face of projection 41, retains the support bolt 40 in the projection 41 against the force of spring 43 and when rotated, effects an axial adjustment of support bolt 40, together with pin 37.

One leg 35' of bellcrank lever 35 forms a support for a cylindrical fulcrum 44 threadedly secured to, and longitudinally adjustable along leg 35' by, a bolt 45 (held by bellcrank lever 35) to vary the effective length of leg 35'. The other leg 35" of the bellcrank lever 35 engages with its terminus a stud 46 which is threadedly secured to, and longitudinally adjustable by, a bolt 47 (held in housing 12) to change the angular position of the bellcrank lever 35 in such a manner that the cylindrical fulcrum 44, depending in which direction the adjusting bolt 47 is turned, is urged with greater or lesser force against the spring 34. The force exerted by the fulcrum 44 on the leaf spring 34 generates a preload therein, which determines a maximum permissible r.p.m. The position of fulcrum 44 along the arm 35' determines the advantage and the spring constant of leaf spring 34, thus determining the proportional range of the r.p.m. regulator.

For providing access to adjusting bolts 29, 40 on the one hand and adjusting bolts 45, 47 on the other hand, housing 12 has a respective opening 12' and 12" normally covered with a removable closure plate 48 and 49, respectively.

The aforedescribed structure permits an adjustment of the idling r.p.m. by means of adjusting screw 29 independently of the adjustment of leaf spring 34.

OPERATION OF THE PREFERRED EMBODIMENT

In the FIGURE, the r.p.m. regulator is shown in a position when the internal combustion engine is at standstill. The externally operable lever 21 is in a position for idling.

For starting the engine, the operating lever 21 is brought into its "full-load" position whereby the fuel quantity control rod 11 is displaced into a starting position by the linkage assembly consisting of the adjusting link 19, the intermediate lever 8, the guide rod 9 and the arm 10. In the starting position of the fuel quantity control member 11, the fuel injection pump delivers to the internal combustion engine a fuel quantity which is in excess of the "full-load" quantities and which facilitates the starting of the engine.

Once the engine has started and the operating lever 21 is maintained, for example, in its "full-load" position, the r.p.m. of the engine continuously increases and the weights 3 swing outwardly under the centrifugal forces from their position shown in the FIGURE. During this outwardly swinging motion of the weights 3, they exert with arms 4, a force through the roller bearing 5 on the governor sleeve 6 which travels distance X against the force of the idler spring 26 and then, with frontal face 24, abuts against the support lever 28. During the displacement X of the governor sleeve 6, which moves in unison therewith, the bolt 16 pulls the fuel quantity control rod 11 from its engine-starting position into the "full-load" position by means of articulated transmission members 7, 8, 9 and 10. The r.p.m. regulator remains in this position during further increase of r.p.m., until the latter reaches a maximum r.p.m. set by the preload of the spring 34. Should this maximum r.p.m. be exceeded by an only partially loaded engine, the axial force exerted by the arms 4 on governor sleeve 6 overcomes the force of leaf spring 34 and, as a result, the governor sleeve 6, moving the support lever 28 away from its abutment pin 37, travels beyond path X. Consequently, the governor sleeve 6 shifts (by means of transmission members 7, 8, 9, 10) the fuel quantity control rod 11 until it assumes a position in which the fuel quantity delivered by the fuel injection pump is decreased to correspond to the momentarily required engine output and to ensure that the r.p.m. is maintained within the proportional range.

Since the forces of the regulator spring 34 are taken up by the pivot pin 33, on the one hand, and, by the abutment pin 37 or the governor sleeve 6, on the other hand, the transmission members 7, 8, 9 and 10 are free from resetting forces under all operating conditions.

If, for example, the fuel quantity control rod 11 engages an abutment in one of its terminal positions and if the operating lever 21 or the governor sleeve 6 continues to shift, the spring 23 of the accumulator 22 is compressed and consequently, only these relatively small forces are transmitted to the linkage system.

The easily accessible support bolt 40 permits the provision of an additional device in contact therewith for the arbitrary adjustment of the abutment 37. Such an additional device may be a lever, an electromagnet or a pneumatic adjusting mechanism. An adjustment of support bolt 40 displaces support lever 28, changing thereby the preload of the leaf spring 34 and the length of path X. In this manner the regulator characteristics are varied. The possibility of such variation is desirable to enable an adaptation of the r.p.m. regulator to different operational conditions of the engine such as overload run or charging run, operation at high altitudes or when minimum power output is desired.

The above-described centrifugal governor device is a regulator that controls an idling and a maximum r.p.m. In one terminal position of operating lever 21 the device determines the idling r.p.m. of the engine, whereas in intermediate positions of the operating lever 21 and in its other terminal position, it sets predetermined fuel quantities. If, in any of these last-named two positions of the operating lever 21 the maximum predetermined r.p.m. is exceeded, the regulator device automatically decreases the r.p.m.

The adjustability of abutment pin 37 to a position, where X= 0, permits to convert without additional changes, the aforedescribed regulator for controlling an idling and a maximum r.p.m., into a centrifugal control device which seeks to maintain any r.p.m. value lying between the idling r.p.m. and a maximum r.p.m. and a maximum r.p.m. and set by the operating lever 21.

Claims

We claim:

1. In a centrifugal governor device for regulating the r.p.m. of an internal combustion engine, where said device is of the known type that includes (A) a governor sleeve displaceable as a function of the engine-r.p.m., (B) a linkage assembly connecting said governor sleeve with a fuel quantity control member to cause an r.p.m.-dependent displacement of the latter, (C) an intermediate lever forming part of said linkage assembly and (D) an arbitrarily settable operating lever connected to said intermediate lever to displace said fuel quantity control member at will, the improvement comprising:

A. a support lever adapted to be abutted and displaced by said governor sleeve;

B. a regulator spring in engagement with said support lever and urging the latter towards said governor sleeve;

C. adjusting means associated with said support lever to vary the distance required for said governor sleeve to travel before abutting said support lever;

D. adjusting means associated with said regulator spring to vary the force exerted by the latter on said support lever; and

E. an idler spring in engagement with said support lever and said governor sleeve and exerting a force opposing a displacement of said governor sleeve towards said support lever.

2. An improvement as defined in claim 1, wherein said support lever is mounted on, and movable about a pivot remote from the path of travel of said governor sleeve.

3. An improvement as defined in claim 1, including adjusting means associated with said idler spring to vary the force exerted thereby on said governor sleeve.

4. An improvement as defined in claim 3, wherein said idler spring is a coil spring arranged in axial alignment with said governor sleeve, said support lever includes an opening through which said coil spring is adapted to extend, said support lever further includes a part that carries said adjusting means associated with said idler spring, said last-named adjusting means supports one end of said idler spring.

5. An improvement as defined in claim 1, wherein said adjusting means associated with said support lever is adapted to vary the position of rest of the latter to vary said distance.

6. An improvement as defined in claim 1, wherein said adjusting means associated with said support lever is adapted to reduce said distance to zero.

7. An improvement as defined in claim 2, wherein said regulator spring is a leaf spring mounted on, and movable about said pivot, said adjusting means associated with said regulator spring includes a fulcrum in engagement with, and adjustable along, said regulator spring to vary the preload force exerted by the latter on said support lever.

8. An improvement as defined in claim 7, including a bellcrank lever formed of two legs and movable about said pivot; means secured to said bellcrank lever and carrying said fulcrum; said fulcrum is in engagement with, and adjustable along one of said legs to vary the effective length thereof; the other of said legs is in engagement with an adjusting means adapted to rock said bellcrank lever about said pivot.