GB2136151A

GB2136151A - A Centrifugal Speed Governor Having Torque Control for Fuel Injection Pumps

Info

Publication number: GB2136151A
Application number: GB08333781A
Authority: GB
Inventors: Jurgen Kunze; Thomas Nagel
Original assignee: DRESDEN KRAFTFAHRZEUG VEB
Current assignee: DRESDEN KRAFTFAHRZEUG VEB
Priority date: 1982-12-27
Filing date: 1983-12-19
Publication date: 1984-09-12
Also published as: RU1820015C; CS251241B1; DE3341144A1; GB8333781D0; DD212165A3

Abstract

The invention seeks to reduce the number of parts required in centrifugal speed governors having torque control wherein the amount of fuel supplied by the fuel injection pump is best adapted to the maximum amount of fuel which is combustible in smoke- free manner in the engine at any given time. Contrary to known solutions, a rocker arm is not required. An adjusting member (5), which is provided in the centrifugal speed governor, is guided in a fixed slot (7) provided in the housing and is supported on an adjustable adapting device (8, 9, 10) which is secured to the housing beneath the rotational axis of the cam shaft of the fuel injection pump (1). <IMAGE>

Description

SPECIFICATION A Centrifugal Speed Governor having Torque Control for Fuel Injection Pumps The present invention relates to a centrifugal speed governor for fuel injection pumps of internal combustion engines, such a governor having a control member which is adjusted by the force of pendulum weights in speed-dependent manner and transmits the control movements to a pivotable adjusting member, said adjusting member being connected to the control member and being guided in a fixed slot provided in the housing, and such a control member thus acts in opposition to a spring lever which is subjected to the force of at least one return spring.Since injection-type engines of motor vehicles operate within a large speed range, it is desirable to adapt the amount of fuel injected (torque control) to the maximum amount of fuel which is combustible in smoke-free manner in the engine at any given time.

Centrifugal speed governors of the abovedescribed type are known (German Patent Specification No. 1 954 834), wherein a rocker arm having a complex structure is pivotally mounted on the adjusting member, and appropriately disposed stops-some of which are resilient-permit movements of the rocker arm to be achieved because one or other stop is always used as a temporary reference. Use of the described rocker arm is considered to be a disadvantage of this solution.

The present invention seeks to provide a more economically feasible solution by reducing the number of parts used in centrifugal speed governors of the above-described type.

For centrifugal speed governors of the abovedescribed type, the invention seeks to provide torque control devices for adapting the amount of fuel supplied by the injection pump to the full-load characteristic of the engine and, contrary to known solution, such a device does not require the rocker arm, whereby the maximum amount of fuel at increasing speed can be changed to achieve a feed rate curve which first rises, then falls, or first falls and then rises.

According to the present invention there is provided a centrifugal speed governor having torque control for fuel injection pumps of internal combustion engines, such a governor having a control member which is adjusted by the force of pendulum weights in speed-dependent manner and transmits the control movement to a pivotable adjusting member, said adjusting member being connected to the control rod and thereby acting in opposition to a spring lever which is subjected to the force of at least one tension spring serving as a speed control spring, characterised in that the adjusting means is guided in a fixed slot provided in the housing, and the adjusting member is supported on an adjustable adapting device which is fixed to the housing beneath the rotational axis of the cam shaft of the injection pump.

The adjusting member is provided in the centrifugal speed governor and acts as a link between the adjusting pin and control rod, said adjusting member being guided in said fixed slot provided in the housing parallel to the rotational axis of the fuel injection pump-and being directly controlled by adapting devices, wherein two adapting devices are provided, one adjustable adapting device being secured to the housing and being disposed beneath the rotational axis of the cam shaft of the fuel injection pump, and the other adjustable adapting device being disposed above the rotational axis of the cam shaft of the injection pump in the spring lever and being capable of being connected to an idling device in known manner.

The present invention will be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 illustrates the kinematic operating principle of the invention; and Figure 2 illustrates the feed rate curves achieved by the present invention.

A control member of a centrifugal governor, comprising axle member 2 and pendulum weights 3, is mounted on the cam shaft of a fuel injection pump 1, which is not shown more fully, and an adjusting pin 4 of said control member transmits the adjusting movement to an adjusting member 5 via a pivotal connection 6, which is guided in a fixed slot 7 formed in the governor housing 26. A connecting member 24 is pivotally mounted on the adjusting member 5 and is connected to a control rod 25 of the fuel injection pump 1, said rod 25 serving to adjust the feed rate.A onearmed spring lever 1 6 is pivotally mounted on a bearing pin 23 and represents the force transmitting member for a tension spring 1 8 which serves as a speed control spring and determines the maximum speed controlled by the governor, the other end of the tension spring 1 8 being disposed on an operating lever 20 connected to a bearing pin 22 which is rotatably mounted in the governor housing 26. The tension spring 1 8 is limited by the stop 21.The position of the adjusting member 5, which determines the maximum full-load quantity, is defined by an adjustable stop 19 in conjunction with an adjustable spring seat 15, an idling spring 11, an adapting spring 13 and a pivotal lever 1 7. The adjusting member 5 is supported by a spring seat 10, which is disposed beneath the cam shaft of the fuel injection pump 1 and is adjustably disposed on the governor housing 26, together with an adapting spring 8.The invention permits the following feed rate curves to be achieved: 1. with increasing speed, a feed rate which first increases, then decreases, in accordance with the curve a-b-c in Figure 2; 2. with increasing speed, a feed rate which first decreases, the increases, in accordance with the curve a-d-c in Figure 2; 3. with increasing speed, a feed rate which is first constant, then decreases, in accordance with the curve e-b-c in Figure 2; or 4. with increasing speed, a feed rate which first rises and then remains constant, in accordance with the curve a-b-f in Figure 2.

A supplementary feed starting position of the adjusting member 5, which is controlled by the idling spring 11 by means of the pivotal lever,1 7, is shown in Figure 2 by the line h-g-e, and hence such position of the control rod 25 is shown in Figure 2 by the line h-g-a.

The maximum speed is limited by the tension spring 1 8 which acts as a speed control spring, and the associated regulating-down curve is shown in Figure 2 by line c-k or f-k. In Figure 2, the speed n is plotted on the abscissa and the control rod travel R, which corresponds to a specific feed rate Q, is plotted on the ordinate.

The feed rate curve according to example 1. is achieved because, at the speed n1, the adjusting pin 4 brings the adjusting member 5 into such a positiOn, via the pivotal connection 6 which is guided in the fixed slot 7 provided in the governor housing 26, that the stop 12 of the idling spring 11 in the adjustable spring seat 1 5 firmly abuts the stop 14 of the adapting spring 13 in the spring seat 1 5. Due to the set initial tension in the adapting spring 13, the spring seat 1 5 acts as a fixed pivot for the adjusting member 5 via the pivotal lever 17.

As a consequence thereof, the adapting spring 8, which is softer than the adapting spring 13, may be compressed, via the stop 9, in the spring seat 10 which is adjustably disposed beneath the rotational axis of the cam shaft in the governor housing 26, whereby the control rod 25 is adjusted towards a higher feed rate via the connecting member 24. At the speed n2, the set travel of the stop 9 in the spring seat 10 is used up, so that the stop 9 becomes the fixed pivot for the adjusting member 5.

As the speed increases further, the adapating spring 1 3 in the adjustable spring seat 1 5 is compressed via the stops 11 and 14 and the pivotal lever 17, and the control rod 25 is adjusted to wards a lower feed rate via the connecting member 24. At the speed n3, the set travel of the stop 14 in the adjustable spring seat 1 5 is used up, and the spring lever 1 6 is pressed away from stop 19 in opposition to the force of the tension spring 18; hence the maximum speed is limited.

The feed rate curve according to example 2. is achieved when the adapting spring 13 has less rigidity than the adapting spring 8. The feed rate curve according to example 3. is achieved when zero travel is set for the stop 9 in the adjustable spring seat 10.

The feed rate curve according to example 4. is achieved when zero travel is set for the stop 14 in the adjustable spring seat 1 5. If two springs are inserted in each of the spring seats 10 and 1 5, instead of one spring 8 for 13, respectively, further adaptation of the feed rate curve can be achieved.

Claims

1. A centrifugal speed governor having torque control for fuel injection pumps of internal combustion engines, such a governor having a control member which is adjusted by the force of pendulum weights in speed-dependent manner and transmits the control movement to a pivotable adjusting member, said adjusting member being connected to the control rod and thereby acting in opposition to a spring lever which is subjected to the force of at least one tension spring serving as a speed control spring, characterised in that the adjusting means (5) is guided in a fixed slot (7) provided in the housing, and the adjusting member (5) is supported on an adjustable adapting device (8, 9, 10) which is fixed to the housing beneath the rotational axis of the cam shaft of the injection pump (1).

2. A centrifugal speed governor having torque control substantially as herein described with reference to and as illustrated in the accompanying drawings.