DE1940372A1 - Fuel injection pump for internal combustion engines - Google Patents

Description

E. 9551
51.-7-1 ^ 69 Su / ΐΠ}

Attachment to

Patent and

Utility model registration

EOBEHT BOSCH GMBH, 7 Stuttgart ¥, Breitscheidstrasse 4-

Fuel injection pump for internal combustion engines

The invention relates to a fuel injection pump for Internal combustion engines with change in the amount of fuel delivered depending on the speed by interrupting the pump delivery at least when the maximum speed is reached due to the opening of a first relief channel of the pump working chamber during the delivery stroke of the Pump piston by means of a reciprocating control element,

—2-

1098H / 0910

BATH ORIGINAL

Robert Bosch GmbH ': R .. 9551 Su / Kb

Stuttgart ... '. "' ■ -. ,,.-.-

'This is due to the pressure fluid being synchronized with the main pump driven auxiliary pump in the sense of its

'is driven' and during its by a restoring force caused decline is slowed down by the fact that there is at least part of the fluid that caused its drainage, must press through a regulating throttle so that the regulating element at a certain throttle cross-section and reaching a certain 'speed due to occurrence of the so-called liquid stop no longer runs back into its starting position at a fixed stop, the Eegel member to change of the control stroke is rotatable and at least one

■ has an inclined control edge. .

In a known fuel injection pump of this type (see German patent specification 1 258 187) is the idle and the maximum speed is automatically "determined by the controller (idle end controller characteristic), but in the not regulated intermediate speed range the injection quantity immediately, changed by the driver through the crawler handle. One injection start adjustment taking place at the same time as this change in quantity, which is often desired, is not provided in this known pump design. The idle end controller this known injection pump requires an adjustable regulating throttle, which is coupled to the control element must »This is relatively time-consuming.

The invention is based on the object for the type of fuel injection pump mentioned at the outset, in which the arbitrary In the injection quantity is done by turning the control element, the Aufsteuerinib as a result of the

1098U / 09 10

BATH ORIGINAL

Robert Bosch GMBH ' .· .' . ■ ^: R »

Stuttgart '■■ -.- ■■ "' ■" '--.-

inclined control edge changes ν eerier! 'less,' costly · idle final government ao% ie a ^ Spritz & egfnnverstellyngVörzU "• see * ¹ - ■ '"".''"' - "'' - '"' ■ · "." - - - "" ■

This problem is solved according to the invention "daduröh solved ^ -that the PlmpenarbeitsratuTi the main pumps -in ö: n - known way (see German patent ~ Ά -28S." 804-) has a second relief channel controlled by the regulating member and that this second relief channel either always closed by the control element, depending on the rotational position. '"or remains closed during the downward movement by a long control edge c after retraction Load and the corresponding position of the accelerator pedal, the second relief channel is closed sooner or later, which results in a load-dependent fuel adjustment.

An advantageous embodiment of the invention is such, that the relief channels are arranged on the regulating member through the limiting edges serving as control edges th ring groove are controlled, which is in constant contact with the pump work space. This is a predetermined one Assignment of start of injection and arbitrarily changeable Injection quantity given.

! Lach an advantageous embodiment of the invention takes place the idle control of the injection pump in that the control element can be rotated arbitrarily via a spring drag element is that when setting in 'direction full load directly at Adjustment in the direction of idling with interposition

109814/0910

. ■ Robert .Bosch -GmI) H - · - _: '. .; ■.; - '_, ..- ■ -. - _- .. ■ ->. R. 9551

his Eeder, · on a lever arranged transversely on the control element . attacks, against the force of the first spring in full: . ■ load rotation on the lever can attack an actuator that is in Direction full load by a spring and in the direction of idling ..:. < is acted upon by a liquid, the pressure of which increases.

■ changes with the speed, so. that. from _s reaches one certain pressure above the idling speed, the actuator by fluid pressure out of engagement with the lever. The final regulation of the speed takes place according to the known principle

of the liquid stroke. - ..._-. "■

An embodiment of the subject matter of the invention is shown in of the drawing and is shown in more detail in the following ... described. Show it:

Fig. 1 shows an axial section through the injection pump and 2 shows a simplified representation of the parts required for idling control on a reduced scale .

The stage Λ .-. Of a graduated piston. "1, 2 serves as the pump and distribution piston of the actual injection pump and stage 2 as a piston of an auxiliary pump. "Axial" movement and a rotary movement about its axis. The forward movement of the piston 1, 2 is carried out by a cam (not shown), the return movement by a spring -3 · During the rotary movement, stage 1 of the piston serves as a distributor.

On the piston 1 an annular groove 4- is arranged, which has a Channel 5 with the pump working chamber 6 represents the injection pump in '

'. . ■ ".- ■■■ .. —5— 1098 14/09 1 0

, BAD ORiGfNAL

Robert Bosch GmbH, R .. · ψ_

commitment. Ίίι the annular groove ¹ V open on the ^; Surface ^: the piston arranged longitudinal grooves 7, which control a supply bore 8, so that during a portion of the suction stroke of the pump piston fuel from a suction chamber 9 of the injection pump via the bore B, one of the Läiigsnuten 7,. the annular groove A and the bore 5 enter the pump working chamber 6. '·. - ·

The suction chamber 9 is supplied with fuel by a feed pump 10 supplied, whereby the feed pump is also driven by the motor, which- is supplied with fuel by the injection pump, is driven. In order to obtain a pressure that increases with increasing * speed in the suction chamber 9, there is a pressure line in the pressure line 10a of the feed pump 10 a pressure control valve 11 is arranged, which 'to a return 10b towards a throttle point 11a contains, the cross section of which through the piston valve 11b is controlled. The piston valve lib is on one Page by the fuel pressure prevailing in the pressure channel and on the other hand by a return spring 11c burdened.

A distributor groove 12 is arranged on the surface of the "piston 1, each of the successive printing strokes of the piston the pump working chamber 6 with one of the pressure lines 13 connects to the injection, not shown valves on the engine and in each of which a pressure valve 14 is installed

The pump working space 6 is via a relief channel 15 in constant connection with an annular groove 16 which is arranged on a control element, now called control slide 17. The control slide 17 works in a cylinder 17a.

10 98 U / 09 10

- - - ':. ■■ -6- ■'"." ■ ■ '■■ ■:

Robert Bosch GMBH . · R. 9551 Su / Kb ^;

Stuttgart

The control slide 17 is in the cylinder iVa by the Auxiliary pump 2 j 2a driven fuel displaced. The outward • Thus, the control slide takes place during the displacement stroke of the pump cylinder 1. On the surface of the piston 2 longitudinal grooves 18 'are arranged, which into the pump text space 19 of the auxiliary pump open and during the suction stroke of the Auxiliary pump open a bore 20 that is in constant communication .with the suction chamber .9. During the pressure stroke of the

P auxiliary pump piston 2 becomes the bore 20 through the auxiliary pump piston closed and the fuel from the pump working space 19 of the auxiliary pump conveyed via a check valve 21 into the cylinder 17a under the control slide 17. Part of this fuel \ d.rd during the delivery stroke of the Auxiliary pump also promoted via a channel 22, which also connects the pump working space 19 with the cylinder 17a. In A throttle point 23 is arranged in this channel 22, the cross section of which can be changed by means of a throttle needle 24. This fuel delivered by the auxiliary pump is the control slide moved against the force of a spring 25, until the annular groove 16, the relief channel 15 with a

fc bore 26 connects which is in constant communication with the Suction space 9 is. As soon as the relief channel 15 with the bore 26 comes into connection, the injection is interrupted.

An annular groove 16 delimiting the annular groove 16 is used to control the bore 26 inclined control edge 27 »so that depending on the rotational position of the control slide 17 of the relief channel 15 accordingly is connected to the bore 26 sooner or later. The second control edge 28 delimiting the annular groove 16 runs likewise inclined and controls a bore 29 which also opens into the suction chamber 9 in the case of the one shown in FIG.

—7—

109814/0910

BATH ORIGINAL

Robert Bosch GmbH - - .R. 9551 Su / Kh

Stuttgart ■ · ■■ * - '. -

In the position of the control slide, this bore 29 is blocked by it. By turning the control slide 17 "the mouth of the bore 29 is opened and is fully open at" a certain rotational position. As soon as the bore 29 establishes a connection between the annular groove 16 ″ and the suction chamber 9, at the beginning of each pressure stroke of the pump piston, part of the fuel it delivers can flow into the suction chamber 9. However, since the control slide 17 is synchronized with the pump piston by the the auxiliary pump 2,2a fuel displaced is moved., the bore of the bore Dex 29 is closed by the oblique control edge 28 depending on the rotational position of the control slide 17 after covering a certain stroke. Only after this closing 29, the injection can begin. ¹ during the inclined control edge 28 is chosen so that with increasing load the cross-section of the bore 29 released by the control edge 28 decreases until it always remains blocked at full load.

In order to be able to adapt the course of the start of injection to the "load course, usually slide 17 has an adjustable stop 3o.

A third bore 31 leads from the cylinder 17a to the suction chamber 9i cLie through the lower end of the control slide 17 is controlled. After through the inclined control edge 27 the bore 26 has been fully opened, and thus determines the outermost position that the control slide I7 at his Entrance takes. ". '

The projecting into the Saugx ^ aum 9 end 32 of the control slide 17 is _executed% flat and slides in an x '· recess 33-a-driver part 3 ² S so that there is a rotational connection between the control slide 17 and driver part 3 ^ without the regulating slide is prevented from its axial movement.

_8th-

T098 1 4/09 1 Q

Robert Bosch GMBH
Stuttgart

The actuating device of this' lever ';35' is shown in Fig * _: · ^ -, -.; ■ · .->. -By-the arbitrary light operated by the driver ^ - s-'Xo ^ - ^; -GaspedaJ. 3.6 a spring, lap link £ 37 with spring .40, yer-. ···, / is pushed. The "starting position" of the - spring drag link _; 37. .will-,, r _:. ' an adjustable idle stop "39 determines« Das ■. ■, -. Spring trailing link can move towards full load directly ..- on the lever, .-., . . *.? 35 attack: in; Direction idle ο but .only - ujnt he, -. Intermediate _t: the spring 40. .Weiteridn circuit acts .in direction Yollast, ...., P to the lever 35 an adjusting piston 4 <1- the "in Richtijmg teör-r, - last by a liquid.. applied. is _f der en, pressure ,. i ,, _r .; .-is controlled as a function of the speed, which is fed via a line 42 from the suction chamber 9. -In the direction of full load, the _f -, _s - _: - adjusting piston 41 is loaded by a ^. The maximum,. delivery rate. vri.rd through an adjustable full load stop. · -.- ■; - 44 determined.-..- ■ .., -. . .; ,, -.,. . - ._. _: .., · -.-. · ■> ■ - .. ■ -

The idle end control device and the injection beginning

work direction vrie follows: ...

As soon as the engine has started, the. Actuating piston 41 b and the spring 40 of the lever 35 T ^^ d so that the control slide 17 is held in a rotational position that corresponds to the ge \ nschten idle speed Suction chamber 9 and thus in front of the actuating piston 41, so that the spring 43, the actuating piston and. so that the lever 35 moves into a position of greater delivery rate. Conversely, when the speed increases, by the spring 40 and the increasing speed with increasing pressure in the suction chamber 9 and thus in front of the adjusting piston 41 of the. Lever 35 ^aVi ^ twisted lower delivery rate.

10 9814/0910

Robert Bosch 'GmIiH E. 9551 Su / Kb

Stuttgart

Once the driver versteilt- the accelerator pedal to larger fuel quantity, the rotational speed, the result is increasing, that the actuating piston ^41: spring 43 is displaced so that it comes out of engagement with the lever ^35: against the force of. ! The spring 40 pushes the lever 35 to abut the Federsch eppglied 37 · in the entire rotational range between the ^Winker: stoppers 39 and 44, the driver can adjust the quantity delivered to the engine arbitrary. -The inclined control edges 27 and 28 run against each other, which is why in this speed range with decreasing delivery rate - the start of injection is shifted to "late".

At full load, the lever 35 is via the spring snap member 37 pressed against the stop 44, the cone slide 17 a Assumes a position in which the bore 29 is always closed remain. The control slide 17 runs back at least up to this full-load speed range with each suction stroke of the pump pistons in its starting position at its stop 30. However, increases If the speed continues to increase, the so-called end control begins, which is carried out here by the so-called liquid stop. During the return of the control slide, the check valve 21 has the effect that all of the control slide is displaced Fuel must flow through the throttle 23, which is set so that at least in the final speed control range the rate of decline of the control slide 17 is braked. Above one through the cross section of the Control throttle 23 specific speed of the pump begins the pressure stroke of the auxiliary pump 2, 2 a before the control slide 17 \ could run back to its original position. As a result of the occurring liquid stop for the control slide 17, this begins its exit in a starting position, above the stop 30, whereby the bore 26 in the course of the

-10-10981 U / 0910

■■ - ■. ■■. ■■■ : '■' .. ': ■ -ΙΟ-

Robert Bosch GmbH '"E. 9551 Su / Kb

Stuttgart .. "'.-

Displacement stroke is controlled at an earlier point in time by the control edge -27, which has a reduction in the injection quantity and, as a result, also the speed of the engine to be supplied. The throttle point 2.3 is "so firmly set" that the desired P-degree (degree of non-uniformity) is reached in the final control.

1098U / 0910

BATH ORIGINAL

Claims (1)

-11- ■ Robert Bosch GmbH ■ .R. 9551 Su / Kb Stuttgart. Expectations 1. j fuel injection pump for internal combustion engines with change in the amount of fuel delivered as a function of the speed by interrupting the pump delivery at least when the maximum speed is reached as a result of upward control a first relief channel of the pump working space during the delivery stroke of the pump piston by means of a reciprocating control element that is driven by the pressure fluid an auxiliary pump driven synchronously with the main pump is driven in the sense of its slope and during its restoring force-induced decline is slowed down by the fact that it passes through at least part of the liquid that caused its drainage Control throttle must press through so-that the control element at a certain throttle cross-section and reaching a certain speed as a result of the occurrence of the so-called liquid stop no longer in its starting position a fixed stop runs back, the control member being rotatable to change the opening stroke and at least has an inclined control edge, characterized in that the pump working chamber (6) of the main pump has a second, controlled by the regulating element (1?), in a manner known per se -12- "109814/0910 Robert Bosch GMBH . . R. 9551 Su / Kb Stuttgart • - relief passage has (29) and that this second discharge duct (29) above by the control member (17) by ^e. . = ■. Rotation position. Either remains closed or · during _; the slope is closed by an inclined control edge (28), covering a ge different path according to the rotational position. 2. Fuel injection pump according to claim 1, characterized in that the relief channels (26,29) through the . limiting edges serving as control edges (27, 28) an annular groove (16) arranged on the regulating element (17) in a controlled manner, which is in constant communication (15) with the pump working space (6) .. J. fuel injection pump according to claim 1 or 2, characterized characterized in that the starting and Aufsteuerlage des Control member (17) in a manner known to sMi by a adjustable stop (30) is changeable. 4. Fuel injection pump according to one of the preceding λ
Claims, characterized in that the control element (17) is arbitrarily rotatable via a spring drag link (37, AO) , which when adjusted in the direction of full load -13-1098 IZ ₊ / 0910 Robert Bosch GmbH - E. 9551 Su / Kb .Stuttgart . directly when setting in the direction of idle with the interposition of his leather (4-0) on a transverse am Control member (17) arranged lever (35) engages, against the. Force of the first spring (4-0) in full load direction an actuator (4-1) can act on the lever (35), that in the direction of full load by a spring (4-3) and in ' A liquid (4-2) acts on it in the direction of idling /, the pressure of which changes with the speed, so that, from a certain pressure above the idling speed, the actuator (4-1) disengages from the lever (35) due to the fluid pressure. ..t . 109814/0910 J * Empty e ι te