US3847127A

US3847127A - Centrifugal rpm governor for fuel injected internal combustion engines

Info

Publication number: US3847127A
Application number: US00421586A
Authority: US
Inventors: H Staudt
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1972-12-05
Filing date: 1973-12-04
Publication date: 1974-11-12
Anticipated expiration: 1991-11-12
Also published as: IT1028518B; PL89538B1; BR7309523D0; DE2259428C3; FR2209049A1; JPS4986721A; ATA1010273A; DE2259428B2; AT330507B; DE2259428A1; GB1451059A; ES421126A1; SU513640A3; JPS5613175B2; FR2209049B1

Abstract

In a centrifugal rpm regulator for fuel injected internal combustion engines, a fuel quantity control rod is provided which receives the forces associated with the displacements of an adapter sleeve which in turn is displaceable under the influence of centrifugal flyweights and as a function of engine rpm. The control rod is limited in the direction of increasing fuel supply by a structure including a first and second cam plate, an intermediate lever, a lever including a cam follower member, and a control apparatus. The first cam plate includes a cam sector with the cam follower member being adapted to abut the cam sector whenever the maximum fuel supply quantity corresponding to a particular rpm is delivered. The second cam plate is mounted with the first cam plate to rotate independently thereof and to also operatively engage with the cam follower member. The control apparatus functions in dependence on the temperature of an operating medium for controlling the second cam plate so that a starting excess fuel quantity is delivered only until a particular operating medium temperature is reached.

Description

United States Patent [1 1 Staudt 1 CENTRIFUGAL RPM GOVERNOR FOR FUEL INJECTED INTERNAL COMBUSTION ENGINES [75] Inventor: Heinrich Staudt,

Markgroningen-Talhausen,

Germany [73] Assignee: Robert Bosch GmbI-I, Stuttgart,

Germany [22] Filed: Dec. 4, 1973 [21] Appl. No.: 421,586

[30] Foreign Application Priority Data Dec. 5, 1972 Germany 2259428 [52] U.S. Cl 123/140 R [51] Int. Cl. F02d 1/04 [58] Field of Search 123/140 R [56] References Cited UNITED STATES PATENTS 3,620,199 ll/l97l Kuhn et al. 123/140 R Primary ExaminerLaurence M. Goodridge Attorney, Agent, or Firm-Edwin E. Greigg Nov. 12, 1974 [57] ABSTRACT In a centrifugal rpm regulator for fuel injected internal combustion engines, a fuel quantity control rod is provided which receives the forces associated with the displacements of an adapter sleeve which in turn is displaceable under the influence of centrifugal flyweights and as a function of engine rpm. The control rod is limited in the direction of increasing fuel supply by a structure including a first and second cam plate, an intermediate lever, a lever including a cam follower member, and a control apparatus. The first cam plate includes a cam sector with the cam follower member being adapted to abut the cam sector whenever the maximum fuel supply quantity corresponding to a particular rpm is delivered. The second cam plate is mounted with the first cam plate to rotate independently thereof and to also operatively engage with the cam follower member. The control apparatus functions in dependence on the temperature of an operating medium for controlling the second cam plate so that a starting excess fuel quantity is delivered only until a particular operating medium temperature is reached.

8 Claims, 7 Drawing Figures PAKNIEB nuv 12 m4 SHEET 1 5 PAIENIEU HEY 'I 2 l SHEET 2 OF 5 m a m m- PATENIEDNUY 12 E374 3.847127 SHEEIEIOF 5 i INJECTED INTERNAL COMBUSTION ENGINES CROSS-REFERENCE TO RELATED APPLICATION BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal rpm regulator for fuel injected internal combustion engines,

and more particularly to fuel injected internal combustion engines such as diesel engines.

The centrifugal rpm regulator of the type under consideration has an adaptor sleeve which is slidable under the influence of centrifugal flyweights, which in turn function in dependence on the rotational speed ofthe engine. The adaptor sleeve transfers the forces associated with its regulatory motions via an intermediate lever to a fuel quantity control rod which adjusts the fuel supply quantity delivered by the fuel injection pump. The excursion of the fuel quantity control rod is limited in the direction of increasing supply quantity by an abutment structure which is rotatable in dependence on the engine rpm and which governs the maximum fuel quantity. The abutment structure is attached to a shaft which is positively connected to the regulator housing, and is coupled to the adaptor sleeve. The abutment structure is equipped with a cam plate which has a cam region that determines the starting excess fuel quantity and also determines the full load fuel supply quantity. A cam follower member which is connected with the fuel quantity control rod abuts this cam region whenever the maximum supply quantity corresponding to a particular rpm is delivered.

2. Description of the Prior Art Centrifugal rpm regulators of this kind, which have an rpm-dependent control of the starting excess fuel quantity can be adjusted in such a way that this starting excess fuel quantity is already shut off at some engine rpm which lies below the idle rpm. In otherwords, the starting excess fuel quantity can no longer be injected when the engine is running. However, this starting excess fuel quantity is readmitted during each new start,

so that when the engine is warm from operation, too much fuel is supplied and the exhaust gases contain at high percentage of uncombusted materials.

The legal requirements for cleanliness of the air each year designate lower and lower limiting values for the percentage of detrimental matter in exhaust gases and,

in order to meet these requirements, the regulators for fuel-injected internal combustion engines must be provided with devices which shut off the starting excess fuel quantity in dependence on the operating temperature of the engine. Devices are already known which open up a supplementary path for the fuel quantity control rod of the injection pump during starting, and this supplementary path is then blocked again in dependence on the temperature of an operating medium or the ambient air. However, in these devices the disadvantage exists that the regulated starting excess fuel quantity is still effective with a running engine, and especially when the engine operates in a very low rpm region under load. i

OBJECTS, SUMMARY AND ADVANTAGES OF v THE INVENTION I i It is, therefore, an object of the present invention to provide a centrifugal rpm regulator of the construction described above which is equipped with a device for achieving a temperature dependent controlled starting excess fuel quantity so that, when the engine is warmed up in operation, the starting excess fuel quantity is no longer metered or only partially metered and the preset starting excess fuel quantity never becomes effective when the motor is running. i

This and other objects are achieved according to the present invention in that a second cam-plate is disposed parallel to the cam plate of the abutment structure and on the same shaft, where this second cam plate also cooperates with the cam follower and where it is rotatable, independently of the first cam plate, by a control apparatus which functions in dependence on an operating medium temperature. When an operating medium temperature is reached, which corresponds to the operationally warmed-up engine the cam lobe of this second cam plate shuts off the cam sector of the first cam plate which determines the starting excess fuel quantity, and during temperatures which are below this 7 point, it at least partially releases the starting excess fuel quantity. 1 i

An advantageous embodimentof the present invention is achieved innthat the control apparatus has a housing which isopen with respect to the interior of the regulator and also co-ntain sa spiral-shaped bimetallic spring, one end ofwhichis fastened on an adjustment shaft and thetother end of which engages the second cam plate. In this,embodiment, the temperaturedependennoperating medium is the air or the lubricating oil inside there-gulator. For this purpose, an electrically heated bimetallic spring can also be utilized.

A furtheradvantageous embodiment of the present invention is achieved in that the control apparatus has a housing which is sealed off with respect to the interior of the regulator and also with respect to the outside, and that it has an adjustment shaft mounted therein on whichone end of aspiral-shaped bimetallic spring is fastenedathe other end of the bimetallic spring being supported by a rotatable adjustment member which is also carried within the housing of the control apparatus. Moreover, according to this advantageous embodiment, the operating medium consists of the cooling water or the lubricating oil of the engine which is derived from the engine via connecting studs into the sealed off housing.

In a further embodiment of the present invention, the operating medium consists of a medium which, for example, is an electrically heated filling medium.

The temperature-dependent operating control apparatus can, therefore, be attached in'a simple fashion to the regulator'in such a way that the housing of the control apparatus is a part of the regulator cover.

BRIEF DESCRIPTION OF THE DRAWINGS I FIG. I is aside view in elevation illustrating a longitudinal section through a first exemplary embodiment of the present invention taken along the line ll in FIG. 2.

FIG. 2 is a front view in elevation illustrating a cross section through the first exemplary embodiment of the present invention taken along'the line lllI in FIG. 1.

FIG. 3 is a side view in elevation illustrating another longitudinal section through a first exemplary embodiment of the present invention taken along the line III- III in FIG. 2.

FIG. 4 is a partial cross-sectional view taken along the line lVlV in FIG. 2.

FIG. 5 is a partial sectional view corresponding to FIG. 4, but for a second exemplary embodiment according to the present invention.

FIG. 6 is a perspective view illustrating the cooperation between certain ones of the more important regulator elements and their cooperation with the equalization device and with the control apparatus which itself operates in dependence on an operating medium temperature.

FIG. 7 is a partial sectional view corresponding to FIG. 5, but for a third exemplary embodiment according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning now to FIG. 1, there is shown a drive shaft 10 of an injection pump (not shown), the injection pump being used with an internal combustion engine. On the shaft 10 there is fastened a centrifugal flyweight regulator 11 whose pivotably mounted flyweights 12 have arms 13 which act on the front surface 14'of a thrust bearing 15. The thrust bearing 15 is mounted on the extension stud of an adaptor sleeve 16 which serves as a control member. The thrust bearing l5 serves to transmit the adjustment forces of the centrifugal flyweight 12 to the adaptor sleeve 16. The adaptor sleeve 16 is itself carried at one end 16a on a cylindrical stud 17 of the drive shaft 10, and at its other end 16b, which faces away from the drive shaft), is provided with latcrally extending guide pins 18, each of which is guided in a guide slot 19 of a force-transmitting lever 21 (see also FIG. 3).

The force-transmitting lever 21 has a cross section that is box-shaped, with a substantially U- or H-shape, and with its two leg portions 22 beingpositioncd to point towards the injection pump. The leg portions 22 contain guide slots 19 for the guide pin 18. At the level of the axis of the drive shaft 10 and of the adaptor sleeve 16, an adjusting element 23 is screwed into the force-transmitting lever 21 and secured there in its installed position by a nut 24. The adjusting element 23 has a plane surface 26, against which a convex front surface 27 of the adaptor sleeve 16 abuts after traversing a first partial distance a.

After the above-mentioned first partial path a has been traversed, the adaptor sleeve 16 acts upon a leaf spring 28 which serves as a starting or idle control spring, whose pre-tension acts on guide pins 18. The leaf spring 28 is adjusted by an adjusting screw 29. The adjusting screw 29 is screwed into the forcetransmitting lever 21 and secured there in its adjusted position by a nut 30.

The force-transmitting lever 21 is a straight twolegged lever having the cross section mentioned above and pivotably mounted on a bearing bolt 31 fixedly attached to the housing 33. The vertical normal position of the lever 21 is determined by a stop 32, fixed within the housing 33. The stop 32 is formed by the frontal surface of an abutment screw 34 which is screwed into the regulator housing 33 in a self-securing fashion.

The force-transmitting lever 21 can be pivoted about the bearing bolt 31 in a counterclockwise direction (FIG. 1). The pivotal motion occurs when the force derived from the centrifugal flyweights 12 and transferred by the adaptor sleeve 16 via the adjusting element 23 to the force-transmitting lever 21 is greater than the re turn force provided by a control spring 35. The control spring 35 is a tension spring disposed substantially vertically with respect to the axis of the adaptor sleeve 16 and suspended between two mounting

slots

36, 37. The first mounting slot 36 is formed in a bearing bolt 36 which in turn is fixed to the housing 33, and the second mounting slot 37 is disposed on an adjustable angle lever 38 which is adjustable in order to preset the maximum rpm. The angle lever 38 is mounted to the forcetransmitting lever 21 by a bearing bolt 39 which passes through both legs 22 of the force-transmitting lever 21. The particular position of the angle lever 38 is determined by an adjustment screw 41, which in turn permits the pre-tension of the control spring 35 to be adjusted. In this way, in an advantageous fashon, the maximum rpm of the regulator is determined.

The adaptor sleeve 16 acting against the resetting forces of the control springs 28 and 35 transfers its control motionsthrough the intermediary action of a control arm 42 and a cam lever 43 as well as through a control arm 42, which has the shape of a U-shaped stirrup (see FIG. 2), is formed by a ball joint 36 (see also FIG. 1). The control arm 42 is mounted in the regulator housing 33 by means of two pivot studs 47 (see FIG. 2). On its one leg 42a the control arm 42 carries a first drag link 49 equipped with a return spring 48, whose func tion will be described in more detail below, and on its other leg 42b it carries a second drag link 52 equipped with a return spring 51 and connecting the adaptor sleeve 16 with the intermediate lever 43. This second drag link 52 carries a bolt 53 at its outermost end, and the intermediate lever 43 is pivotally attached to the bolt 53.

The intermediate lever 43 has a guide slot 54 (FIGS. 2 and 3) within which operates a guide pin 55 of a control arm 56 which in turn is fixedly connected with a shaft 57 mounted in the regulator housing 33. Outside of the regulator housing 33 there is fastened on this shaft 57 an operating lever'58 (FIG. 2) with whose aid the shaft 57 and therefore the control arm 56 are pivotable. The transmission ratio of the two-amred intermediate lever 43 changes with the position of the control rod 45 in a known fashion. The intermediate lever 43 and the spring-type accumulator 44 are connected with one another by a connecting bolt 59.

The end of the control rod 45 nearest the regulator has fastened thereto a plate 61 to which the spring-type accumulator 44 and therefore also the intermediate lever 43 are pivotably attached by a bolt 62 (FIG. 3). In addition to being connected to the intermediate lever 43, operable by the adaptor sleeve 16, the plate 61 is also pivotably connected with a freely swivelling. carried along abutment lever 63. The abutment lever 63 has a pin 64 which is fastened on 65 lever arm 64 of a control lever 67. The pin 64 defines a pivot axis for the abutment lever 63. The control lever 67 is pivotably mounted on two bearing studs 66 within the regulator housing 33. The abutment lever 63 has a cam follower member 68 at one end 63a, which abuts against a first cam plate 69 of abutment 70 for the purpose of limiting the maximum fuel quantity delivered at each rpm of the engine, i.e., it cooperates with this first cam plate 69. The other end 63b (see also FIG. 6) of the abutment lever 63 has a slot 63c within which a bolt 71 fastened to the plate 61 is received. Through this connection the abutment lever 63 is moved during movement of the control rod 45.

The abutment 70 has a substantially bushing-shaped construction which is mounted on the lever shaft 57 and is rotatable in dependence on the engine rpm. The rpm-dependent rotation of the abutment 70 is. controlled by the adaptor sleeve 16 in that its axial displacements are transferred via the ball joint 46 on the control arm 42, the leg 42a of the control arm 42 and the first drag link 49 to an engaging arm 72.

The first drag link 49 (see FIGS. 2 and 6) is equipped with a drag lever 73 which engages the engaging arm 72 via a bolt 74, and opposes the resiliently yielding force of the return spring 48, but only in one direction of the control lever 42 which occurs during increasing rpm. The return spring 48 urges the first drive link 49 to remain in its normal position which is determined by a path limiter, and this path limitation is formed substantially by a set screw 75 securely positioned within the drag lever 73. This set screw 75 permits the admustment or correction of the rotational position, assigned to a particular position of the adaptor sleeve 16 of the abutment 70 or of the cam plate 69.

In the neighborhood thereof or parallel to the cam plate 69, in addition to the rotatable abutment 70, there is carried on the lever shaft 57 serving as an axis fixed with the housing a second cam plate 77 which, just as the first cam plate 69, acts together with the cam follower member 68 of the abutment lever 63 (see especially FIG. 6); and which, independently of the first cam plate 69, is rotatable (see also FIG. 4) by a control apparatus 78. The control apparatus operates in dependence on the temperature prevailing in the interior of the regulator housing 33, i.e., within the regulator interior volume 76.

This second cam plate 77 has a step-shaped cam lobe 79, although it could also be provided without steps but with a descending curve. The stepped cam lobe 79 (see FIGS. 3 and 6) is intended to block a cam sector 81 of the first cam plate 69, which determines the starting excess fuel quantity, whenever an operating medium temperature assigned to the operationally warmed-up engine exists in the interior volume 76 of the regulator, and to release the starting excess fuel quantity at least partially whenever the temperatures lie below that point. The operating medium can also be the electrical heating of a bimetallic spring (see FIG. 7). The required rotational motion of the second cam plate 77 is effected within the control apparatus 78 (see especially FIG. 4) by a spiral bimetallic spring 82, one end 820 of which is fastened in a slit 83 formed in an adjustment shaft 84 and the other end 8212 of which engages a recess 87 in the second cam plate 77 through the intermediate action of a lever 85 having a pin 86. The control apparatus 78 has a housing 88 which, in the present example, is a part of the regulator cover 89 and within which the adjustment shaft 84 is mounted, whose rotational position is determined by a setting nut 90. A second cover 91 closes the regulator housing 33 from above.

As may be clearly seen from the perspective view of FIG. 6, the first cam plate 69 has, in addition to the cam sector 81, a cam sector 92 which determines the full load fuel supply quantity. The cam sector 81 determines the starting excess fuel quantity. The step-like transition between the two

sectors

92 and 81 is formed by an offset 93 which, during the starting process and in a cold engine, serves as a start lock during the starting process in a cold engine while the cam follower member 68 pivots past the offset 93 and is located in the region of the cam sector 81. In FIG. 6, however, the second cam plate 77 is drawn in the position in which it lies when the engine has been operationally warmed up, and in this position, the cam follower member 68 can pivot only into the position shown in dotted lines and designated by 68'. In a cold engine, the second cam plate 77 is rotated in a counterclockwise sense and by appropriate pivoting in such a manner that it does not impede the pivoting of the abutment lever 63 until the lever reaches the cam sector 81 of the first cam plate 69. In this completely pivoted position, the starting excess fuel quantity is retained until such time as the regulator reaches its turn-off rpm and the control rod 45 is moved by the intermediate lever 43 in the direction of arrow D (FIG. 3). Since, during this regulating process, the adaptor sleeve 16 urges the abutment carrying the first cam plate 69 into further rotation, the first drag link 49 begins to function and permits a further movement of the adaptor sleeve 16 and of the control arm 42 in spite of the fact that the abutment 70 remains stationary. During that time the engaging arm 72 and the bolt 74 of the drag lever 73 are stationary and the return spring 48 is being pretensioned.

As soon, however, as the regulator pulls back the control rod 45 in the stop direction (arrow D), to below the position corresponding to the full load fuel supply quantity, and when the cam follower member 68 moves from the sector 81 along the offset 93, at least into the position designated by 68 in FIG. 6, the first drag link 49 is relieved and it moves to the abutment 70 and therefore the first cam plate 69, for example, moves into its second position designated 69' and indicated in dotted lines. In this position, the cam follower member 68 cooperates with the sector 92 of the first cam plate 69 and determines the fully load fuel supply quantity. The pre-tension force of the first drag link 49 is large enough so that the frictional force generated at the first cam plate 69, i.e., the force generated by the pressure force of the cam follower member 68, is overcome primarily in the region of sector 92. This pretension force, however, may not be so large that the desired start lock at the offset 93 is retained longer than is permissible.

The return spring 51 of the second drag link 42 must have a pre-tension many times greater than that of the return spring 48 of the first drag link 49 because the second drag link 52 acts in the same direction as the first drag link 49 and if the return spring 51 were too soft and if also the control rod had a lot of friction, the result would be that the second drag link 52 could yield. This is not permissible for reasons of reliability because the arrest motion of the regulator must be guaranteed in every case. During other operational conditions,.for example, when, because of the braking action of the engine, the operating lever, and, therefore, the internal regulator parts, are already located in the stop position and the regulator would tend to shut off the fuel, as, for example, during overrunning operation,'the second drag link 52 permits a regulatory motion of the adaptor member 16 and of the control arm 42 by pre-tensioning the return spring 51. This avoids an overload of the interior parts of the regulator.

The drag lever 73 of the first drag link 49 and also a drag link 52 are mounted on one of the two pivotal studs 47 of the control arm 42, and the return springs 48 and 51 which are embodied as spiral springs are supported on the one hand at

legs

42a and 42b of the control arm 42 and on the other hand at the drag levers 73 and 95. g

In order to guarantee the regulatory functions which are described below, during all operational conditions, the spring-type accumulator 44 is located between the control rod 45 and the intermediate lever 43 and cooperates with the two

drag links

49 and 52 and acts as an elastically resilient third drag link.

The accumulator 44 has a return spring 96 and has a pre-tension which is greater than the resistance to motion of the control rod 45 but at the same time small enough so that, during increasing rpm outside of the starting range, the rotational motion of the cam plate 69 is not hindered.

The swivel position of the control lever 67 determines the position of the pivotal axis 64' of the abutf ment lever 63 and therefore also the position of the control rod 45 which is assigned to the first cam plate 69 of the abutment 70. The swivel position of the control lever 67 is fixed in the direction of increasing fuel supply quantity by means of an externally adjustable set screw 97 equipped with a head 9721. A playcompensating spring 98 pushes a bolt 94 attached to the control lever 67 against the head 97a in order to hold the control lever 67 in this position.

The second exemplary embodiment is distinguished from the first exemplary embodiment of FIGS. 1-4 and 6 only in the control apparatus 100, which has been changed in its construction with respect to control apparatus 78. The control apparatus 100 is placed in a housing 101 that is a part of the regulator cover 102 and which is sealed, both with respect to the interior of the regulator and with respect to the outside. In the housing 101 an adjustment shaft 103 is carried to which one end 104a of a spiral bimetallic spring 104 is fastened. The other end l04b of the spring 104 is supported by a rotatable adjustment member 105 also carried within the housing 101. The control apparatus 100 operates in dependence on an operating medium temperature just as the control apparatus 78. The operating medium is preferably engine cooling water or lubricating oil which is delivered through two connecting studs 106 into the sealed portion 101 of the housing 101. The studs 106 also serve as exit ports for the operating medium. The adjustment shaft 103 carries an adjustment lever 107 on the portion which lies outside of the sealed portion 101a and within a housing portion 101 which is open with respect to the interior of the regulator. The adjustment lever 107 engages the second cam plate 77 external to the pivotal axis thereof. The sealed portion 101a may also contain a nonflowing medium as the operating medium, for example,

it may be an electrically heated filling fluid (see FIG.

The perspective view of FIG. 6 shows that cooperation of the more important regulator elements that cooperate with the first cam plate 69 of the abutment and with the second cam plate 77. The intermediate lever 43, which is also coupled with the plate 61 and with the control rod 45 and its associated connecting links have been omitted for clarity as has the second drag link 52 connected to the leg 42b of the control arm 42. This representation according to FIG. 6 serves above all for the purpose of better understanding the following description of the method of operation of the regulator according to the present invention. Only the adjustment shaft 84, the bimetallic spring 82 and the lever are shown from among the elements of the control apparatus 78. This figure would be logically correct also for the second exemplary embodiment of FIG. 5, because the lever 85, the shaft 84 and the bimetallic spring 82 need only be replaced by the corresponding parts of the control apparatus 100.

The first exemplary embodiment of the regulator according to the present invention and as shown in FIGS. 1-4 and 6 is a so-called adjustable rpm regulator or a multi-rpm regulator and operates as follows:

The movable parts of the regulator are shown in their normal rest position, the operating lever 58 and therefore the control arm 56 as well as all of the parts starting with the centrifugal flyweight 12 up to the control rod 45 are shown in the arrested position.

When the internal combustion engine is started, the operating lever 58 and therefore the control arm 56 (see FIGS. 2 and 3) are pivotably moved in the direction of arrow B into their full load position, or more exactly, into the position corresponding to the maximum rpm to be regulated. During this process, the control rod 45 is pushed by the intermediate lever 43 through the intermediate action of the spring-type accumulator 44 in the direction of arrow C and into the starting position. Also during this process, the plate 61 acting via the bolt 71 (see FIGS. 2 and 6) carries along the abutment lever 63 whose cam follower member 68 swings from the position shown in FIGS. 1, 3 and 6 into the position 68' shown in dotted lines in FIG. 6 where it abuts the outer limit of the second cam plate 77 when the engine is warm. When the engine is cold, the second cam plate 77 lies outside of the active range of the abutment lever 63 and its cam follower member 68. However, in this case the cam follower member 68 also pivots in the same operating position past the offset 93 of the first cam plate 69 into the region of the cam sector 81. The cam follower member 68 can also stop a short distance before, if the path of the control rod 45 is limited by other stops (not'shown). In this starting position of the control rod 45, the injection pump delivers a quantity of fuel to the internal combustion engine which is in excess of the full load fuel quantity and facilitates starting of the engine.

In view of the fact that the second cam plate 77 has a step-shaped cam lobe 79, a reduction of the starting excess fuel quantity by the control apparatus 78 occurs in steps when the engine warms up; and depending on the operating medium temperature, either the full load fuel quantity or the maximum starting excess fuel quantity or some quantity in between these two is metered out for the-purpose of starting the engine. In the exemplary embodiment shown in FIGS. 1 to 4 and 6 including the control apparatus 78, the adjustment shaft 84 is fixedly mounted within the housing 88 and the bimetallic spring 82 actuates the lever 85 in the clockwise sense (FIG. 6) when the operating medium temperature increases. In this way, the second cam plate 77 is rotated in the counterclockwise sense, and the cam lobe 79 comes to lie more or less outside of the sweep region of the cam follower member 68. A basic adjustment may be obtained by turning the adjustment shaft 84 in the housing 88. The lock nut 90 is tightened after the adjustment process so that the adjustment shaft 84 can no longer turn. The process described, which occurs during the start-up, and the rotation of the second cam plate 77 which occurs during the warm-up period of the engine can also be seen in FIG. 3 where it is to be noted that the rotational directions shown are in the opposite sense because of the reverse direction of the view.

Once the motor has started, and if the operating lever 58 is held, for example, in the full-load position, the rpm increases further and the centrifugal flyweights 12 pivot out of the interior position shown and outwardly under the influence of centrifugal forces. In this way, the centrifugal flyweights 12 press, in a known fashion, with their arms 13 against the thrust bearing against the adaptor sleeve 16, which slides, in opposition to the force of the leaf spring 28 (see FIG. 1) until its convex front surface 27 abuts the plane surface 26 of the adjusting element 23 screwed into the force-transmitting lever 21. During this motion of the adaptor sleeve 16 through the partial path a which is already traversed during the first few seconds of the starting process, the adaptor sleeve 16 moves the ball joint 46 by the same amount and attempts to pull the control rod 45 by the intermediate action of the pivoted control arm 42, the intermediate lever 43 and the accumulator 44 in the direction of arrow D from the starting position into the full load position or beyond that into the stop position.

During this motion of the adaptor sleeve 16, the first drag link 49, which is also connected with the control arm 42 (see FIGS. 2 and 6), attempts to rotate the abutment 70 in the clockwise sense. During starting of a cold engine, when the second cam plate 77 does not lie within the sweep region ofthe cam follower member 68, the offset 93 on the first cam plate 69 prevents rotation of the abutment 70 until the cam follower member 68 reaches the position 68' shown in dotted lines in FIG. 6. This position however is reached only when the preset rpm, which is chosen with the operating lever 58, is reached or is slightly exceeded. During that process, the adapter sleeve 16 has moved beyond the partial path a by another incremental amount b during which time the force-transmitting lever 21 has turned in the counter-clockwise sense under the influence of the increasing sleeve force and has lifted from its stop 32. As soon as the cam follower member 68 has taken up the position 68, the first cam plate 69 can turn furthcr into the position designated 69' Until the full load rpm is reached or slightly exceeded, the first drag link 49 has been biased in the manner described above. When the second cam plate 77 is in the position shown in FIGS. 3 and 6 in an operationally warmed-up engine, then the cam follower member 68 cannot travel beyond the position 68' and the first drag link 49 does not need to be biased.

During the full load operation, the rotational position of the abutment 70 changes depending on the corresponding position of the adaptor sleeve 16 and so does the position of the first cam plate 69. The cam sector 92, in which the cam follower member 68 lies, determines the position of the control rod 45 that corresponds to each rpm and therefore determines the corresponding maximum fuel quantity. By suitably constructing the cam sector 92 any desired deployment of the supply quantity can be realized in a known manner (adaption process). In a partially loaded engine, if the maximum set rpm is exceeded, which is tantamount to an adaptor sleeve path greater than a b, the forcetransmitting lever 21 moves further in the counterclockwise sense and the adaptor sleeve 16 moves the control rod 42, the intermediate lever 43, the accumulator 44 and the control rod 45 into a position in which the fuel quantity of the injection pump is reduced to the point where it corresponds to the power delivered by the engine, and the rpm is maintained within the proportional region of the regulator or until the fuel supply is entirely shut off.

In order to compensate for the path differences of the control rod 45 in the direction of arrows D or C, occasioned during the control of the adaptation process and caused by the cam sector 92 of the first cam plate 69, the second drag link 52 is inserted in the connection between the control arm 42 and the intermediate lever 43.

The method of operation of the second exemplary embodiment, as far as it concerns the function of the regulator, is exactly the same as that of the first exemplary embodiment. Because of the changed construction of the control apparatus compared to the control apparatus 78 of the first exemplary embodiment, the second cam plate 77 is actuated in a somewhat changed way by the control apparatus 100. When the operating medium temperature changes, whether it is the temperature of the cooling water or the temperature of the lubricating oil delivered through the chamber 101a, the bimetallic spring 104 turns in such a way that the adjustment shaft 103 and, therefore, the adjustment lever 107, are turned. Since the end 104b of the bimetallic spring 104 is attached to the housing through the adjustment member 105, the basic position of this control apparatus 100 can occur by turning the adjustment shaft 105 within the housing 101.

The temperature range of the operating medium in which the second cam plate is actuated is dependent on the type of the motor and the choosen operating medium. When the lubricating oil is chosen as the operating medium the temperature range is, for example, plus 5 to minus 10 centigrade, for below these degrees the motor needs a starting excess fuel quantity.

The third exemplary embodiment is distinguished from the second exemplary embodiment of FIG. 5 only in the control apparatus (FIG. 7), whose construction has been changed to a minor extent with respect to control apparatus 100. The control apparatus 110 is placed in a housing 111 that is a part of a regulator cover 112 and has a sealed portion 111a within which the adjustment shaft 103, the adjustment member 105 and the spiral bimetallic spring 104 are mounted like the same parts in the sealed portion 101a of FIG. 5. The sealed portion 119 contains a non-flowing filling fluid as the operating medium, which is electrically heated by a heating element, for example a well-known heating plug 113. As the filling medium therermay also serve air or gas heated by the heating plug 113.

What is claimed is:

1. In a centrifugal rpm regulator for fuel injected internal combustion engines, especially diesel engines, including a housing mounting; centrifugal weight means, an adaptor sleeve slidably displaceable under the influence of the centrifugal weight means and as a function of engine rpm, an intermediate lever, a fuel quantity control rod, the adaptor sleeve transmitting the forces associated with its controlled motions resulting from its slidable displacement through the intermediate lever to the fuel quantity control rod for adjusting the fuel quantity delivered by an injection pump used 7 in conjunction with the regulator, an abutment structure which serves to limit the movement of the control rod in the direction of increasing fuel supply, the abutment structure being fixedly connected to the regulator housing and being pivotable as a function of engine rpm to thereby determine the maximum fuel quantity, and means coupling the adaptor sleeve to the abutment structure, the abutment structure having a cam plate including a cam sector that determines the starting excess fuel quantity and also the full load fuel supply quantity, a shaft on which the cam plate is mounted, a cam follower member, and means connecting the cam follower member to the control rod, the cam follower member being adapted to abut the cam sector whenever the maximum fuel supply quantity corresponding to a particular rpm is delivered, the improvement comprising:

a. a further cam plate, wherein the cam plate of the abutment structure and said further cam plate constitute a first and second -cam plate, respectively, said second cam plate being mounted on the shaft mounting the first cam plate to be parallel therewith and rotatable independently thereof, said second cam plate also being adapted to operatively engage with the cam follower member; and

b. a control apparatus which functions in dependence on the temperature of an operating medium such that when an operating medium temperature is reached which corresponds to an operationally warmed-up engine a portion of the second cam plate blocks the cam sector of the first cam plate from being engaged by the follower member thereby preventing the delivery ofa starting excess fuel quantity, and when the operating medium temperature reached is below a temperature which corresponds to an operationally warmed-up engine, the cam follower member abuts the cam sectorof the first cam plate so that at least a partial starting excess fuel quantity is delivered.

2. The regulator as defined in claim 1, wherein said control apparatus includes a housing which communicates with the interior of the regulator, a spiral shaped bimetallic spring within said housing, and an adjustment shaft, with one end of said spring being fastened to said adjustment shaft and the other end of said spring engaging said second cam plate.

3. The regulator as defined in claim 1, wherein said control apparatus includes a housing which is sealed off from the interior ofthe regulator and'the exterior of the engine with which the regulator is used, a spiral shaped bimetallic spring within said housingan adjustment shaft and a rotatable adjustment member, withone end of said spring being fastened to said adjustment shaft and the other end of said spring being supported by said rotatable adjustment member.

4. The regulator as defined in claim 3, wherein said control apparatus includes connecting studs through which the operating medium is delivered into said apparatus housing, and wherein the operating medium is engine cooling water.

5. The regulator as defined in claim 3, wherein said control apparatus includes connecting studs through which the operating medium is delivered into said apparatus housing, and wherein the operating medium is engine lubricating oil.

6. The regulator as defined in claim 3, wherein a sealed portion of the housing of said control apparatus includes an operating medium, which is an electrically heated filling medium.

7. The regulator as defined in claim 1, wherein said control apparatus includes a housing, a portion of which is sealed off from the interior of the regulator and the exterior of the engine with which the regulator is used, and a portion of which communicates with the interior of the regulator, a spiral shaped bimetallic spring within said housing, an adjustment shaft including an adjustment lever located within that portion of the apparatus housing which communicates with the interior ofthe regulator, said adjustment lever engaging said second cam plate external to its pivotal axis, and a rotatable adjustment member, with one end of said spring being fastened to said adjustment shaft and the other end of said spring being supported by said rotatable adjustment member.

8. The regulator as defined in claim 2, further comprising a cover, wherein said apparatus housing is formed as part of the cover.

Claims

1. In a centrifugal rpm regulator for fuel injected internal combustion engines, especially diesel engines, including a housing mounting; centrifugal weight means, an adaptor sleeve slidably displaceable under the influence of the centrifugal weight means and as a function of engine rpm, an intermediate lever, a fuel quantity control rod, the adaptor sleeve transmitting the forces associated with its controlled motions resulting from its slidable displacement through the intermediate lever to the fuel quantity control rod for adjusting the fuel quantity delivered by an injection pump used in conjunction with the regulator, an abutment structure which serves to limit the movement of the control rod in the direction of increasing fuel supply, the abutment structure being fixedly connected to the regulator housing and being pivotable as a function of engine rpm to thereby determine the maximum fuel quantity, and means coupling the adaptor sleeve to the abutment structure, the abutment structure having a cam plate including a cam sector that determines the starting excess fuel quantity and also the full load fuel supply quantity, a shaft on which the cam plate is mounted, a cam follower member, and means connecting the cam follower member to the control rod, the cam follower member being adapted to abut the cam sector whenever the maximum fuel supply quantity corresponding to a particular rpm is delivered, the improvement comprising: a. a further cam plate, wherein the cam plate of the abutment structure and said further cam plate constitute a first and second cam plate, respectively, said second cam plate being mounted on the shaft mounting the first cam plate to be parallel therewith and rotatable independently thereof, said second cam plate also being adapted to operatively engage with the cam follower member; and b. a control apparatus which functions in dependence on the temperature of an operating medium such that when an operating medium temperature is reached which corresponds to an operationally warmed-up engine a portion of the second cam plate blocks the cam sector of the first cam plate from being engaged by the follower member thereby preventing the delivery of a starting excess fuel quantity, and when the operating medium temperature reached is below a temperature which corresponds to an operationally warmed-up engine, the cam follower member abuts the cam sector of the first cam plate so that at least a partial starting excess fuel quantity is delivered.

3. The regulator as defined in claim 1, wherein said control apparatus includes a housing which is sealed off from the interior of the regulator and the exterior of the engine with which the regulator is used, a spiral shaped bimetallic spring within said housing, an adjustment shaft and a rotatable adjustment member, with one end of said spring being fastened to said adjustment shaft and the other end of said spring being supported by said rotatable adjustment member.

7. The regulator as defined in claim 1, wherein said control apparatus includes a housing, a portion of which is sealed off from the interior of the regulator and the exterior of the engine with which the regulator is used, and a portion of which communicates with the interior of the regulator, a spiral shaped bimetallic spring within said housing, an adjustment shaft including an adjustment lever located within that portion of the apparatus housing which communicates with the interior of the regulator, said adjustment lever engaging said second cam plate external to its pivotal axis, and a rotatable adjustment member, with one end of said spring being fastened to said adjustment shaft and the other end of said spring being supported by said rotatable adjustment member.