DE2449859A1 - Throughput regulator for fuel injection pump - has intermediate and main operating levers separated by leaf springs - Google Patents

Abstract

The pump has a casing (1) containing a fuel suction chamber (7) and a cylinder (2) within which a piston (3) slides and rotates. The piston has an internal passage (8) through which fuel is discharged. A sleeve (16) round the piston allows excess fuel to return to the suction chamber and its position determines the quantity delivered. An auxiliary lever (18) pivoting on a pin (19) has one end in a groove in the sleeve (16) and the other resting on the sleeve (27) of a centrifugal governor (23). A main lever (30) also has one end in the piston sleeve (16), pivots on the same pin (19) and has the other end attached to a main regulating spring (33). A leaf spring (39) is placed between the main and auxiliary levers (30, 18).

Description

R. 2 3 81

September 6, 1974 Su / Kb

Attachment to

Patent and

Utility model registration

ROBERT BOSCH GMBH, 7 Stuttgart 1

Speed controller for fuel injection pumps

The invention relates to a speed controller for fuel injection pumps of internal combustion engines with an intermediate lever which, on the one hand, is connected to a delivery quantity adjustment member the injection pump is coupled and to which, on the other hand, a speed sensor with speed-dependent force counter to a willkürDich changeable force of a main control spring and the force of one connected in series to this up to a stop deformable second spring engages.

-2-

609818/0099

2 38 t

There is an in-line injection pump of this type known with a centrifugal adjuster, which counter to a main control spring of variable preload works and thereby adjusts a control rod. The displacement of the sleeve of the pliehkraftverstellers is transmitted directly to the control rod on the one hand by a centrally mounted control lever and on the other hand by means of a second lever rigidly connected to the above lever. transfer a leaf spring consisting of several single leaves, which is held at both ends on an angle lever acted upon by the main control spring and up to an adjustable one Stop is deformable on this angle lever. The leaf spring thus works together with the main control spring Adjusting movement of the centrifugal force first counteracts it, taking it first with increasing forces to deform the leaf spring up to its stop and then only to deform the main control, spring is coming. The leaf spring, which is constantly in contact with its stop during normal operation, is thus automatically adjusted The starting excess quantity that switches off is achieved. The control lever and the angle lever in this arrangement each have a separate one Axis as a swivel bearing.

The arrangement described above is very complex, especially with regard to the attachment and design of the leaf spring and their attitude. The control lever and the angle lever each have a separate axis, which is disadvantageous Makes arrangement space-consuming and complex. Due to the separate arrangement of the levers, large lever movements are necessary, which also disadvantageously requires a large working capacity of the Pliehkraftverstellers.

The object of the invention is, in the case of an injection pump of the type described above, while maintaining the smallest possible dimensions in particular in the working direction of the speed sensor an input

809818/00 9 9 ■

-> 24,9859

direction to create a starting surplus in a simple way is achieved, which is automatically reduced to the normal injection quantity with increasing engine speed and with which can also be combined with an adjustment device or idle speed control, of the former with a further increase in speed causes a reduction in the fuel injection quantity in the sense of a positive adjustment.

This task is solved in that around the axis of the Intermediate lever is a one-armed, with the intermediate lever cooperating rocker arm is pivotable, at the end of the Main control spring engages and a .Druckfeder is arranged between the and the intermediate lever, the stroke of which in both directions is limited by stops. According to an advantageous embodiment of the invention, the compression spring is unilateral attached to the drag lever or the intermediate lever, essentially along the lever and perpendicular to the working direction of the speed sensor in one formed by cranking the lever Space-extending leaf spring formed,

which can be deformed by the levers until they rest against one another.

With this arrangement, the distance formed by the cranking between the rocker arm and the intermediate lever in the working direction of the speed sensor can be kept as small as possible and a soft spring to switch off the excess start-up quantity with increasing engine speed can be accommodated, for example opposite an equally soft helical compression spring does not require any additional guidance and consequently also the regulation influencing friction of such a spring in the guide is avoided. The leaf spring is also very simple as Stamped part executed. The interposition of the leaf spring between the rocker arm and the intermediate lever makes it easier Way a limitation for the maximum deformation of the leaf spring is achieved, which in connection with the only one-sided fastening of the lever is a significant space-saving advantage forms and allows the possibility of a further adjustment device to be provided between both levers.

609 8 18/0099 ~ * ~

- 4 - 2 3 δ ί

A further development of the invention is that the leaf spring a cross-section reduction in its central area has, which further consists in that the cross-sectional reduction is formed by a recess. Doing this can be beneficial a soft leaf spring with sufficient stability can be achieved in a simple manner, with the size of the recess the spring rate of the leaf spring can be determined.

Another embodiment of the invention is that in the area of the recess of the leaf spring on the drag or on Intermediate lever an adjustment capsule is arranged, which serves as a movable stop between the drag lever and intermediate lever. In this way, a "matching device" is arranged in a particularly space-saving manner, with which in the event of a further increase in speed a reduction in the fuel injection quantity in the sense of a positive adjustment or an adjustment in Sense of regulation is achieved.

Further designs according to the invention can be found in the subclaims and their advantages are described in the following Description explained in more detail. Four embodiments of the subject matter of the invention are shown in the drawing as Speed controller shown using the example of a distributor injection pump and described in more detail below. Show it:

Fig. 1 shows a first embodiment with a leaf spring as a compression spring

-5-

609818/0 0 99

2 3 6 ί

Pig. 2 shows a plan view of the leaf spring according to the Pig embodiment. 1,

Fig. 3 shows a second embodiment with "an adjustment capsule,

M shows a third embodiment, in the case of the adjustment capsule and leaf spring are attached to the same lever,

5 shows a partial section through the fastening of the adjustment capsule according to the embodiment of 'Fig. H,

6 shows a plan view of the leaf spring according to the exemplary embodiment according to FIGS. 4 and

7 shows a fourth embodiment in which a cylindrical spring is used as the compression spring.

In a housing 1 of a fuel injection pump, a pump piston 3 operates in a cylinder bore 2, which is set in a reciprocating and simultaneously rotating movement against the force of a return spring, not shown, by means not shown. The pump working chamber 4 of this pump is supplied with fuel from a suction chamber 7 via longitudinal grooves 5 arranged in the outer surface of the pump piston and a channel 6 running in the housing 1 as long as the pump piston executes its suction stroke or assumes its bottom dead center position. Once closed at the beginning of the pressure stroke and, after a corresponding rotation of the pump piston, the duct 6, the fuel in the pump chamber ¹ Y is conveyed into a passage extending in the pump piston longitudinal channel. 8 From the longitudinal channel 8, the fuel is further over

-6-

609818/0099

238 T

a branching radial bore 9 and a distributor longitudinal groove 10 arranged in the surface of the pump piston one of Pressure lines 11 supplied. The pressure lines 11 are in accordance with the number of engine cylinders to be supplied on the circumference the cylinder bore 2 arranged distributed and lead over each

> a
Weil / check valve 12, which opens in the conveying direction, to the injection valves (not shown) on the individual cylinders of the internal combustion engine.

The suction chamber 7 is extracted from a fuel tank via a feed pump Ij5 l4 supplied with fuel. A pressure control valve 15 is parallel to the fuel feed pump 13 the pressure in the suction chamber is controlled in a known manner.

An annular slide 16 is displaceable on the pump piston 3., the one with the longitudinal channel 8 in communication radial bore 17 opens during the pressure stroke of the pump piston 3 and thus the end of delivery or that of the pump piston Determined delivery rate conveyed into the pressure lines 11. The fuel flowing out after opening flows into the suction chamber 7 back.

The ring slide 16 is moved via an intermediate lever 18, which can be pivoted about an axis I9 firmly inserted into the housing is and engages at one end with a head 20 in a recess 21 of the ring slide 16. On the other arm of the intermediate lever 18 engages a centrifugal governor 23 as a speed signal generator at. The centrifugal governor driven by a gear (not shown) in accordance with the pump piston speed 2J has a carrier 24 on which centrifugal weights 25 are arranged are. Centrally on the axis 26 of the centrifugal governor, a sleeve 27 is arranged displaceably, at the bottom Attack the end of nose-shaped parts 28 of the flyweights 25 so that the sleeve during the deflection of the flyweights through the ■

609818/0099 - 7

Centrifugal forces are shifted axially on the axis 26 and at the same time the intermediate lever 18 and the ring slide 16 moves. The intermediate lever has a friction-free and torque-free transmission of the control movement of the centrifugal governor A hemispherical expression 29 at the point of application of the sleeve 27.

A one-armed rocker arm 30 is pivotably arranged on the same axis 19 independently of the intermediate lever 18. This lever is mounted symmetrically to the intermediate lever 18 and has a recess Jl ₉ into which the intermediate lever 18 protrudes, so that the two levers can be pivoted independently of one another. The endays of the two levers therefore overlap.

At the end of the rocker arm 30, a main control spring 33 is attached hinged to this. For this purpose, one end of the main control spring 33, which is designed as a tension spring, is attached to a bolt 34 attached, which penetrates the rocker arm in a hole and has a head 35 on the opposite side. An idling spring can be located between the head 35 and the rocker arm 30 36 be arranged. The other end of the main control spring is suspended from an arbitrarily adjustable lever 37 · Further is an adjustable full load stop 38 is provided for the rocker arm.

The rocker arm 30 and the intermediate lever 18 are both cranked, so that when the two levers come into contact with one another, a parallelogram-like space is created. Both levers run 'essentially we borrowed in this position parallel to each other. In the space between the rocker arm 30 and the intermediate lever 18 protrudes a leaf spring 39 * which, in the present example, is connected to the outer end of the rocker arm 30 with a rivet HO. The leaf spring is about

60981 8/0099

bent from its center in the direction of the Pliehkraftversteller 23 and also has a tongue-shaped bent End 4l, which rests on the intermediate lever 18. The leaf spring tries to push the two levers apart.

The injection quantity control of the injection pump described above according to FIG. 1 works as follows:

Depending on the position of the ring slide 16, during the pressure stroke or the delivery stroke of the pump piston 3, the radial bore 17 and thus the relieving connection from the working chamber 4 to the pump suction chamber 7 is opened up sooner or later and thus the fuel demand in the pressure lines 11 is interrupted. In the uppermost position of the ring slide 1β, the maximum or the entire amount of fuel delivered by the pump piston 3 is thus the pressure lines 11 supplied. The further the ring slide is moved down, the earlier it will be the radial bore 17 is opened and the promotion is interrupted. In the starting position shown in FIG. 1, the rocker arm 30 rests on the full-load stop 38, while the intermediate lever 18 by the leaf spring 39 on the sleeve 27 of the centrifugal adjuster 23 pressed w ± d. The deflection of the With the intermediate lever 18, the control slide 16 is moved into its uppermost position at the same time, that of promoting a fuel excess equals. After starting the internal combustion engine, the centrifugal weights 25 are deflected by the increasing speed, so that the sleeve 27 is moved upwards and with increasing speed the intermediate lever 18 against the force the leaf spring 39 until it rests against the rocker arm 30 pivots. At this moment the fuel is overflow the normal full load amount is reduced. In the further course of further increase in speed, depending on the preload, the Main control spring 33 of the intermediate lever 18 together with the Sch2spp-

_ 9 609818/0099

lever 30 is swiveled at the latest when the cut-off speed is reached and the ring slide 16 is moved further downwards. During normal operation, the rocker arm 30 and the intermediate lever are located 18 to one another constantly. According to the invention, however, the leaf spring 39 can also serve as an idling spring. In in such a case, the spring 36 would be dispensed with - as shown in Fig. 7 - and the spring 39 would in a "part of its stroke as a starting spring in the wider area as Serve idling spring.

The leaf spring 39 can of course also be attached to the intermediate lever 18 in an analogous manner and be supported against the rocker arm 30. A soft but dimensionally stable leaf spring to obtain, this is, as can be seen from Figure 2, advantageously provided with a recess I and something for it wider. The spring stiffness in connection with the blade thickness is determined by the width of the webs a. The leaf spring can be provided with one or more bores 43 for their attachment to one of the levers.

In Fig. 3 essentially the same arrangement is shown, only an adjustment capsule 44 is provided here on the intermediate lever 18 '. The intermediate lever and the rocker arm are located here in the position after switching off the start excess.

The adjustment capsule 44 in the exemplary embodiment according to FIG. 3 consists of a capsule 47 * placed vertically on the intermediate lever 18 '. which is open towards the rocker arm 30 and in which a bolt 45 is arranged, which is guided in a bore 48 in the bottom of the capsule, and at its extreme end outside the capsule has a stop 49 in the form of a locking ring with a washer. At the end of the bolt adjacent to the rocker arm 30 it has a head 46 which serves as a stop for a compression spring 50 clamped between it and the bottom of the capsule 47. By interposing washers at the stop 49 of the bolt the preload of the compression spring can be varied.

609818/0099

- ίο -

2 38 I.

When the levers 30, 18 'are not pressed against one another, the head 46 protrudes beyond the intermediate lever 18 *. To this end, the Dimension the recess 42 in the leaf spring 39 so that the head 46 of the bolt moves freely through this recess can. The head 16 thus initially serves as a stop between the rocker arm 30 and the intermediate lever 18 '. Only when it rises Speed and increasing adjustment forces in front of the centrifugal governor 23, the bolt is gradually counter to the force of the compression spring 50 moved until it comes to a flat contact between rocker arm and intermediate lever. This shift causes at the same time a shift in the ring slide and a reduction in the amount of fuel injected. Only when the limiting speed is reached the force of the main control spring 35 is then overcome by the sleeve force and the ring slide 16 continues downwards in the direction of a minimal fuel bait or its interruption postponed.

With the adjustment capsule, a positive adjustment or an adjustment in the control sense is thus achieved, which means that the full-load characteristic, which, for example, normally runs in parallel, becomes a slight one from a certain speed. IJoigung assumes that is determined by the spring characteristics of the compression spring 50 and the displacement of the bolt 45. The starting spring. 39 i * ¹ of its embodiment with a recess 42 here allows very effective manner without any significant additional requirements place in the working direction of the centrifugal governor both a starting quantity means and an adjusting means.

In Fig. 4 is another embodiment of the invention Solution shown, which is provided in an injection pump that works in the same way as that according to embodiment 1 and 3. In this case, the leaf spring 39 'is common attached with the adjustment capsule 44 'on the intermediate lever 18' '. The adjustment capsule 44 'is greatly simplified,

6 09818/0099

- 11 - 2 38

in that the only capsule used is a bracket or a U-shaped bent sheet metal part 52 which is riveted ^{onto the intermediate lever 18 T 'together with the leaf spring 39'.} In Fig. 5 the design of this adjustment capsule is drawn out larger and in Fig. 6 the design of the leaf spring 39 'is shown, which in this case has a pointed tongue-shaped end and has two fastening holes 53 at the other widened end. The recess 42 'of the leaf spring 39' is adapted to the dimensions of the bolt 45 with its head 46. In this exemplary embodiment, the leaf spring advantageously has a wide fastening base which ensures stable attachment of the leaf spring.

The leaf spring in the examples shown above is first basically made of metal and made in one layer. In a particularly advantageous manner, however, the leaf spring can also be made of bimetal. It arises because of the different elongation at different temperatures a preload or spring rate of the leaf spring that changes with temperature. The leaf spring is advantageous in this way executed that in the cold state they have the greatest rigidity or pre-deformation in the sense of pushing apart Has rocker arms and intermediate levers. As the temperature rises, the rigidity or the pre-deformation decreases. Heated up the leaf spring is driven by the fuel inside the injection pump. So if the leaf spring is cold you need one larger sleeve force of the speed signal transmitter or a higher speed to switch off the starting excess quantity. So you get by appropriate selection of the material and dimensioning of the leaf spring, the possibility of increasing the starting quantity depending on the temperature and also the possibility of switching off this excess quantity completely from the start when the injection pump is at operating temperature. This has the additional advantage of reducing the harmful exhaust gases when the associated internal combustion engine is started .

-12-

609818/0099

2U98.59

2 38 ^

If the spring serves as an idling spring at the same time, so can a residual stiffness that has not been changed by the temperature is available for idling control.

In the exemplary embodiment shown in FIG. 7, which is provided in an injection pump which operates like the one described above, a helical spring 55 is used instead of a leaf spring. This spring, which is designed with a soft characteristic curve, serves as a starting spring in the first stroke range and as an idling spring in the upper, stiffer range. The spring 55 is guided by a bolt 56 which at the same time determines the maximum distance between the levers 30 '"and 18 ^t1! When the motor takes up the load, the spring 55 can now move the intermediate lever 18''' beyond the full load position into the starting position , which guarantees a "run-up" of the motor.

-13-

609818/0099

Claims (1)

? 3 3 \ Expectations 1. Speed controller for fuel injection pumps of internal combustion engines with an intermediate lever which is coupled on the one hand to a delivery quantity adjustment member of the injection pump and to which on the other hand a speed sensor
with speed-dependent force against an arbitrary one
changeable force of a main regulating spring and the force of a second spring connected in series with this spring, which is deformable up to a stop, characterized in that,
that around the axis (19) of the intermediate lever (18,18 ', 18 ")
one-armed, cooperating with the intermediate lever
The rocker arm (30) is pivotable, at the end of which the main control spring (33) engages and a compression spring is arranged between the and the intermediate lever (I8, l8 ', l8 ")
Stroke is limited in both directions by stops. 2. Speed controller according to claim 1, characterized in that
that the compression spring as one-sided on the drag or on
Intermediate lever attached, essentially along the. Lever and perpendicular to the working direction of the speed sensor (23) in an intermediate space formed by the cranking of the lever extending leaf spring (39,39 ') is formed, which through to the contact of the levers (I8, 18 ^!, 18 ", 30) to each other
this is deformable. -14- 609818/0099 2449R53
■ - 1.4 - 2 30 1 or 2 3. Speed controller according to claim l /, characterized in that the leaf spring (39 * 59 ') in its middle area one
Has reduction in cross-section. 4. Speed controller according to claim 3, characterized in that the cross-section reduction through a recess (42,42 ') is formed. 5. Speed controller according to claim 4, characterized in that the leaf spring (39, 39 ') has a curved end (41) as an abutment to one of the levers. 6. Speed controller according to claim 5, characterized in that In the area of the recess (42, 42 ') of the leaf spring on the drag lever or on the intermediate lever, an adjustment capsule (44, 44') is arranged that serves as a movable stop between the rocker arm and intermediate lever. I ₁ . Speed regulator according to claim 6, characterized in that the adjustment capsule (44) consists of a bolt (45) which 1st,
the lever to which the adapter capsule is attached / in a Penetrates the bore and has a stop (46) between one side of the lever and a pretensioned compression spring (50) is arranged; their bias by the location
a second stop (49) of the bolt (45) which cooperates with the other side of the lever can be determined. 609818/0099 - 15 - 2 3? t S. Speed governor according to Claim 7, characterized in that the bolt (45) and the compression spring (50) are arranged in a capsule-shaped housing ( ¹ Tf) which is firmly connected to one of the levers. 9. Speed controller according to claim 7, characterized in that the bolt (45) and the compression spring (50) from a U-shaped bent sheet metal part (52) firmly connected to one of the levers be added, which is attached to the leaf spring at common attachment points on one of the levers. ¹⁰ . Speed governor according to one of the preceding claims, characterized in that the leaf spring (39 * 59 ') ^a bimetal consists us and is biased more in the cold state. 11. Speed controller according to claim 1, characterized in that ' a cylindrical spring is used as a spring, which is guided on a bolt, which is inserted through both levers maximum distance and thus the largest spring stroke determined. 12. Speed controller according to one of the preceding claims, characterized in that the compression spring at the same time serves as an idling spring and starting spring. 609818/0 099