GB2200767A

GB2200767A - A centrifugal governor for injection pumps in internal combustion engines

Info

Publication number: GB2200767A
Application number: GB08802019A
Authority: GB
Inventors: Cornelio Leonardi; Sieghart Maier
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1987-02-06
Filing date: 1988-01-29
Publication date: 1988-08-10
Anticipated expiration: 2008-01-29
Also published as: GB8802019D0; DE3703628A1; JPS63198732A; GB2200767B

Abstract

A centrifugal governor for injection pumps in internal combustion engines has a governor member (16), adjustable in dependence upon rotational speed, and a governor level (19), which transmits the displacement of the governor member (16) and that of an arbitrarily actuable adjusting member (22, 23) to a fuel quantity control rod (20). A stop lever (30) actuated by a control lever (33) has a stop (29) cooperates with a counter-stop (28) on a connecting bar (27) located between the governor lever (19) and the governor rod (20) to limit the full-load delivery quantity. A second device (39) limits the delivery quantity on starting. To adjust the delivery quantity on starting, to a value which is less than the full-load quantity, the second device (39) has a second stop (40) on the stop lever (30) and a second counter-stop (41) disposed on the governor lever (19), at least one of which is displaceable in the direction of pivoting of the governor lever (19). <IMAGE>

Description

A CENTRIFUGAL GOVERNOR FOR INJECTION PUMPS IN INTERNAL COMBUSTION ENGINES The present invention relates to a centrifugal governor for injection pumps in internal combustion engines.

In a known centrifugal governor, disclosed in Swiss Patent Specification No. 319 357, the device for limiting the quantity of fuel necessary for starting comprises a second counter-stop, located on the bar connecting the governor rod and the governor lever, which second counter-stop is set back with respect to the first counter-stop when the bar is in a position corresponding to full-load. The second counter-stop protrudes over the first counter-stop in the direction of pivoting of the stop lever to such an extent that, when the stop lever is in its deflected position and the governor lever is displaced beyond the fullload position, it engages with the stop on the stop lever and hence blocks any further displacement of the governor lever towards a position in which a larger quantity of fuel would b delivered for starting.

In this type of device for limiting the fuel quantity on starting, said quantity is fixed and thus cannot be subsequently adapted to different internal combustion engines. Furthermore, the starting quantity can only be limited to a value which is greater than the full-load quantity.

It would therefore be advantageous if a device could be provided in which the fuel quantity required on starting is adjustable and furthermore, in which the starting quantity is not restricted to a value which is greater than the full-load fuel quantity.

In accordance with the present invention there is provided a centrifugal governor for an injection pump in an internal combustion engine, having a governor member which is adjustable due to the force of flyweights, in dependence upon rotational speed, a twoarm governor lever, which transmits the displacement motion of the governor member to an injected fuel quantity control member of the injection pump, which two-arm governor lever is pivotally mounted on a journal of an adjusting member for the purpose of arbitrarily moving the fuel quantity control member, one end of the governor lever being articulated to the governor member and the other end to a bar connected to the fuel quantity control member, a stop lever including a stop which co-operates with a counter-stop on the bar, and is adjustable in the direction of motion of the fuel quantity control member so as to limit the full-load fuel delivery quantity, a control lever acting on the stop lever and pivotal about a fixed pivot axis and actuable by the governor member, which control lever, when the governor member is in a displacement position which it takes up when the internal combustion engine is at a standstill or is below idling, displaces the stop out of the displacement path of the counter-stop, and a limiting device for limiting the delivery quantity necessary for starting, the limiting device having a second stop disposed on the stop lever and a second counter-stop disposed on the governor lever, the second stop and the second counter-stop being mounted on their respective associated levers in such a way that they can only be moved into abutment with one another by pivoting the governor lever when the stop lever is in a deflected position wherein the second stop and the second counter-stop are adjustable in the direction of the pivot path of the governor lever.

The centrifugal governor in accordance with the present invention has the advantage that the fuel quantity required on starting may be adjusted and may also be of a smaller value than the full-load delivery quantity as required. The latter is particul any significant for pressure-charged engines, which usually require starting quantities that are smallerthan the full-load quantity or smaller than the suction quantity.

The invention is described further hereinafter, by way of example only, with reference to the accompanying drawing, which is a section, schematically represented, through one embodiment of a centrifugal governor in accordance with the present invention.

A known flyweight governor 12 is fixed on a camshaft 10 of an injection pump 11 for an internal combustion engine, and its flyweights 13 move away from the camshaft 10 in a known manner under the effect of the centrifugal force against the force of governor springs 14. The governing movements of the flyweights 13 are transmitted by way of bell crank levers 15 to a governor sleeve 16 which acts as a governing member.

The governor sleeve 16 is provided with a sliding block 26 which is axially displaceably guided on a guide pin 17 screwed into a housing 18. A two-arm governor lever 19 transmits the axial displacement motion of the governor sleeve 16 to a control rod 20, which determines the adjustment of fuel delivery quantity of the injection pump 11. As the novernor lever 19 moves, as a result of the displacement of the governor sleeve 16, it pivots about a journal 21 fixed to a lever 22. The lever 22 is disposed on a shaft 23 mounted in the housing 18 and, together with an operating lever 24, which projects through the housing 18 and is also disposed on the shaft 23, forms an adjusting member for arbitrary movement of the governor rod 20 and hence for arbitrary alteration of the delivery quantity.In a position corresponding to idling, the operating lever 24 abuts against an idling stop 25.

One end of the governor lever 19 engages a pin 26a on the sliding block 26 of the governor sleeve 16 and its other end is articulated to a connecting bar 27, which in turn is articulated to the control rod 20 and converts the pivoting motion of the governor lever 19 into a corresponding displacement motion of the control rod 20. The connecting bar 27 has a first counter-stop 28, which co-operates with a first stop 29 on a stop lever 30. The stop lever 30 is articulated to a supporting bolt 31, which in turn is held in the housing 18. If a lock nut 32 is unscrewed, the supporting bolt 31 may be screwed into the housing 18 to a greater or lesser extent, so that the first stop 29 on the stop lever 30 may be moved in the direction of displacement of the first counter-stop 28.

A two-arm control lever 33 is also disposed on the shaft 23, and one end is connected to the stop lever 30 by a pin 35, which engages in a slot 34 in the stop lever 30. The other end of the control lever 33, which is provided with a guide pin 36, is acted upon by a compression spring 37, which endeavours to press the control lever 33 against a stop 38 on the housing 18. The guide pin 36 is coaxially disposed with respect to the governor sleeve 16 and, when the governor sleeve 16 is in its certain positions, as in its resting position shown, the guide pin 36 abuts against the end face of the governor sleeve 16 due to the effect of the compression spring 37.

The first stop 29 on the stop lever 30 and the first counter-stop 28 on the connecting bar 27 serve, in a known way, to limit the quantity of fuel delivered by the injection pump for full load. Furthermore another device 39, for limiting the delivery quantity required for starting, is provided. This limiting device 39 comprises a second stop 40 on the stop lever 30 and a second counter-stop 41 on the governor lever 19. The second stop 40 is in the form of a member or lug 42 on the lower side of the stop lever 30 and the second counter-stop 41 is in the form of an adjusting screw 43, which may be screwed into the governor lever 19 transversely with respect to its longitudinal axis and projects from said lever on both sides. A lock nut 44 is provided, which when loosened, allows the fixing screw to turn and hence adjust the counter-stop 41 transversely with respect to the governor lever 19 and approximately parallel to its direction of pivoting motion.

The centrifugal governor.operates as follows: The drawing shows the centrifugal governor with the camshaft 10 at zero rotational speed. The flyweights 13 of the flyweight governor 12 are in their inner position and the end face of the governor sleeve 16 abuts the pin 36 of the control lever 33. As a result of this abutment, the lever 33 is disposed against the force of the spring 37 away from the stop 38 on the housing 18. The stop lever 30 is located in a position, by way of the pin/slot connection 34,35, in which the first stop 29 is clear of the displacement path of the first counter-stop 28 and the second counter-stop 40 is in the displacement path of the second counter-stop 41.

As shown, in order to start the internal combustion engine, the operating lever 24, which has already been swung along a pivot path from its resting position on the idling stop 25 in an anti-clockwise manner, causes the governor lever 19 to pivot by way of the journal 21 to the extent that the second counter-stop 41 of the governor lever 19 abuts against the second stop !2 on the stop lever 30. This prevents further pivotal movement of the governor lever 19 and further displacement of the control rod 20 towards a position corresponding to an increase in the quantity of fuel delivered.

The quantity of fuel delivered during starting is thus limited. By correspondingly adjusting the adjusting screw 43, the second counter-stop 41 is located in such a way that the starting quantity is less than the full-load quantity determined by the first stop 29 and by the first counter-stop 28.

When the internal combustion engine has started and as speed increases, the flyweights 13 move outwards and move the governor sleeve 16 to the left (in the drawing) by way of the ball crank levers 15.

The governor lever 19 is hence pivoted in the clockwise direction and moves the governor rod 20 in the direction indicated by "St-op". The control lever 33 pivots, due to the influence of the spring 37, in the clockwise direction until it abuts against the shoulder 38 on the housing 18. The stop lever 30 is thus pivoted in a clockwise direction, by way of the pin/slot connection 34,35, as a result of which the first stop 29 is pivoted into the displacement path of the first counter-stop 28 on the connecting bar 27.

At the same time, the second stop 40 is swung out of the displacement path of the second counter-stop 41. When the stop lever 30 is in this position, the device 39 for limiting the quantity delivered on starting is inoperative and the device for limiting the full-load delivery quantity, which is formed by the first counter-stop 28 and the first stop 29, becomes operative. If the rotational speed of the camshaft 10 decreases again, the governor lever 19 may only pivot in the anti-clockwise direction until the first counter-stop 28 on the connecting bar 27 comes into abutment against the first stop 29 on the stop lever 30. The pivot path of the governor lever 19 is thus larger than the pivot path necessary for adjusting the quantity of fuel delivered on starting.

Since, however, the device 39 for limiting the delivery quantity on starting is inoperative when the stop lever 30 is in this position, the governor lever 19 is not prevented from pivoting up to the full-load limitation.

Claims

1. A centrifugal governor for an injection pump in an internal combustion engine, having a governor member which is adjustable due to the force of flyweights, in dependence upon rotational speed, a two-arm governor lever which transmits the displacement motion of the governor member to an injected fuel quantity control member of the injection pump, which two-arm governor lever is pivotally mounted on a journal of an adjusting member for the purpose of arbitrarily moving the fuel quantity control member, one end of the governor lever being articulated to the governor member and the other end to a bar connected to the fuel quantity control member, a stop lever including a stop which co-operates with a counter-stop on the bar and is adjustable in the direction of motion of the fuel quantity control member so as to limit the full-load fuel delivery quantity, a control lever acting on the stop lever and pivotal about a fixed pivot axis and actuable by the governor member, which control lever, when the governor member is in a displacement position which it takes up when the internal combustion engine is at a standstill or is below idling, displaces the stop out of the displacement path of the counter-stop, and a limiting device for limiting the delivery quantity necessary for starting, the limiting device having a second stop disposed on the stop lever and a second counter-stop disposed on the governor lever, the second stop and the second counter-stop bei.ng mounted on their respective associated levers in such a way that they can only be moved into abutment with one another by pivoting- the governing lever when the stop lever is in a deflected position and wherein the second stop and the second counter-stop are adjustable in the direction of the pivot path of the governor lever.

2. A governor as claimed in claim 1, wherein the second stop is not adjustable in the direction of the pivot path of the governor lever.

3. A governor as claimed in claim 1, wherein the second counter-stop is not adjustable in the direction of the pivot path of the governor lever.

4. A governor as claimed in any of claims 1 to 3, wherein the second stop comprises a member which projects away from the stop lever and the second counter-stop is in the form of an adjusting screw, which may be screwed into the governor lever, substantially transversely with respect to its longitudinal axis.

5. A governor as claimed in claim 4, wherein the adjusting screw projects from both sides of the first governor lever,

6. A centrifugal governor for an injection pump in an internal combustion engine substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.