DE1153940B - Self-regulating pump for fuel injection in internal combustion engines that works with a reciprocating movement - Google Patents

Description

The subject of the invention is a self-regulating device that operates with a reciprocating movement Pump for fuel injection in internal combustion engines, d. H. a pump, its delivery rate per working cycle at least from a certain drive speed of the pump according to the requirements the increase in this speed decreases.

Such pumps working with a reciprocating movement are known; in such Pumping is effected hydraulically by a reciprocating piston that is mechanically driven from the outside during its own slope, which coincides with the delivery stroke of the pump, the slope a control member, which preferably has the shape of a piston valve and during at least part of the period between the start of the piston’s decline and the start of its next slope during its own decline, which it under the influence of a z. B. executes the return force supplied by a return spring, conveys liquid via a throttle point, whereby it is braked. This has the consequence that a certain drive speed of the Pump to the control element, which is preferably an outlet line for the conveyed by the pump Fuel controls, no longer comes into its rest position, from which it normally his Entrance begins, but is stopped beforehand by the so-called "liquid stop", so that its stroke the smaller and its influence in the sense of a reduction in the useful promotion of the The pump becomes larger, the more the drive speed of the pump reaches a certain speed exceeds.

If, as is usually the case, the fluid which the opening of the movable control element has caused under the control element, d. H. under the piston valve by one not with one Throttle point provided channel comes, this channel must be closed during the decline of the control element so that the throttle point influence the stroke of the same in the desired manner can.

It is also already known in the channel through which the exit of the movable control member causing liquid gets under this to switch on a check valve. However, it can it happens that for some reason this valve does not close immediately or does not close tightly, especially as a result of contamination. This is based on the braking effect of the throttle point Regulation disturbed, so that there is a risk of a reciprocating motion

working self-regulating pump

for fuel injection

in internal combustion engines

Applicant:

Pierre Etienne Bessiere,
Neuilly-sur-Seine (France)

Representative: Dipl.-Ing. H. Seiler, Berlin 19,

and Dipl.-Ing. H. Stehmann,
Nuremberg, Essenweinstr. 4-6, patent attorneys

Claimed priority:
France of May 11, 1960 (No. 826 877)

Pierre Etienne Bessiere, Neuilly-sur-Seine

(France),
has been named as the inventor

There is runaway in the motor supplied by the pump.

The invention aims in particular to address this risk to avoid.

For this purpose, according to the invention, the channel through which the outlet of the movable control element (Piston valve) generating liquid arrives, except through the check valve controlled by a forcibly driven by the internal combustion engine slide, which with the Check valve is connected in series and opens the relevant channel shortly before the point in time to which the check valve normally opens to allow the liquid to move to the movable one Control element can get, and which closes this channel immediately after the point in time at which normally the check valve closes.

In this training, the normal operation of the check valve is not due to its presence of the slide changed, but if the check valve blocked in its open position remains, the opening and closing of the

309 670/95

■ / channel concerned by the slide during a time which is slightly longer than that for which the check valve opens this channel when it is working normally. However, this difference in the opening times of the channel is of practically no importance, since in general the malfunction of the check valve is only of short duration. It is essential that the slide is in a positive drive connection with the machine and that

Liquid produced by the fuel to be pumped by the pump or by another suitable Liquid can be formed, fed through an inlet line 12, which from the beginning of the Upstroke of the piston 10 is closed, and the promotion of this liquid in the lower Part of the cylinder 8 takes place through a channel 13 which is provided with devices which a Flow of the liquid only in the

thus the opening and closing of the channel with io linder 11 going to the cylinder 8, but sense

Safety takes place, which would not be the case with an only force-fit drive.

1 shows, by way of example, a schematic axial section of a fuel injection pump according to the invention for feeding a diesel engine; Fig. 2 is a section along the line II-II of

Fig. 1;

Fig. 3 shows schematically another embodiment of the invention.

do not allow in the opposite sense. The outward movement of the piston valve 7 stops as soon as it begins its lower edge exposes an outlet line 14 opening into the cylinder 8.

The decrease (downward stroke in the drawing) of the spool is indicated by a Return spring 15 generated, which was compressed during the hanging. This down Directional stroke begins as soon as the piston 2 is his

The actual injection pump exhibits a main 20 own decline begins. As a result of the

cylinder 1, in which a piston 2 works, its devices in the channel 13, ~ which

which an axial reciprocating motion causes the liquid to flow back through this channel

by means of a cam (not shown) or another lower part of the cylinder 8 to the cylinder 11

whose drive means is given, which of the prevent the piston valve during its

The shaft of the motor is driven, at which 25 this fluid is reduced by another

the injection pump is attached. This piston press channel 16, in which a throttle point 17

closes immediately at the beginning of its hanging (upward is switched on, whose cross-section is preferably

stroke or delivery stroke) an opening 3 through which can be regulated, for. B. by means of a center screw 18,

an inlet line opens into the cylinder, which and which either outside the pump or in

in turn, the auxiliary cylinder 11 opens through a feeder 30 (not shown). This will make the pump is fed.

At least one delivery line 4, which contains a check valve, extends from the cylinder 1 and leads to an injection nozzle, not shown.

In the cylinder 1 also opens an outlet line 6, which prevents the pump when it opens, To promote fuel via line 4 to the injection nozzle or the injection nozzles. That Opening and closing this line 6 are controlled by a control element, which the shape a piston valve 7, which is displaceable within a cylinder 8 and has a groove 9. When the piston valve is in a position in which this groove is a connection between the two sections of the outlet line opening into the cylinder 8 at different heights 6 produces, this outlet line is open, so that then the fuel from the piston 2 is not through the delivery line 4, but braked by the lei decline of the piston valve, since this the liquid must press through the throttle point 17.

As long as the piston 2 and with it the piston 10 are driven at a speed which is less than a certain limit speed, the piston valve 7 reaches below the Pressure of the spring 15, in spite of the braking mentioned, its rest position, which is due to its abutment a preferably adjustable stop 19 is determined before the pistons 2 and 10 have a new opening kick off. The stroke of the piston valve is below this limit speed largest value, so that the from the piston 2 in the delivery line 4 and to the injection nozzle or the Injector fuel amount delivered also has its maximum value. Beyond this limit speed however, the piston valve no longer reaches its rest position, but becomes more or less

device 6 is conveyed, e.g. to stop in the storage container 5 ° prematurely by the liquid jet, to return. which at the beginning of the next hanging anew

The piston slide 7 is designed in such a way and is conveyed into the channel of the cylinder 8 and one controls that it forms what is known as a "fluid stop" from a certain drive speed. Consistency of piston 2 of the pump to the outlet - which is the stroke which the piston slide line 6 during the delivery stroke (upstroke) 55 must run before the line 6 again of the piston 2 opens the earlier and thus the delivery opens, the shorter the higher the drive speed of the pump per delivery stroke, the more the piston 2 and 10 compress the limit speed exceeds, whereby the from the piston 2 to the injection nozzle or the injection nozzles of the mo-

decreases, the more the drive speed of the piston 2 exceeds a certain speed.

For this purpose, the piston slide is hydraulically in 60 gate, on which the relevant injection pump

the sense of his own pendulum (also upward in the drawing, stroke directed) during the Delivery stroke of the piston 2 driven by liquid, which is in synchronism with the Main piston 2 working auxiliary piston 10 is promoted, which is preferably by a widened Stage of the piston 2 is formed and operates in an auxiliary cylinder 11. This cylinder is the is appropriate, the amount of fuel delivered decreases accordingly.

The control effect achieved by the piston valve 7 obviously depends on the tightness of the Devices to prevent some of the liquid from passing through during his decline promotes the channel 13 instead of through the channel 16 provided with the throttle point 17

Check valve 20 switched on channel 13 came? in certain cases not be tight enough. the end for this reason, with the check valve 20, which normally controls the channel 13, a Rotary valve connected in series, which of the machine inevitably avoiding any about only frictional connections is driven and in synchronism with the pistons 2 and 10 of the pump is controlled so that it opens channel 13 shortly before the point in time at which nor- ίο times the check valve 20 opens this channel, and closes it immediately after the point in time at which the check valve 20 should normally close.

The normal operation of the check valve is therefore not prevented by the presence of the slide changed, which only takes its place in the event of a failure of this valve, namely for a time which is generally only short (a few seconds), so that by the operation of the slide slight increase in the opening time of the channel 13 did not cause any serious disturbance of the operation of the engine can generate.

According to a particularly interesting solution, the piston 2 of the pump or that with it becomes rigid connected auxiliary piston 10 is used as a slide for controlling the channel 13. So that the piston 2 or the piston 10 can perform this additional task, this will rotate around their Axis granted, or it is for this purpose exploited the rotary movement, which the piston 2 executes in order to e.g. B. to fulfill the task of a distributor, which during the successive delivery strokes of the Pump feeds the pumped fuel to several different injection nozzles.

In the pump shown in FIG. 1, the auxiliary piston 10 fulfills the task of the slide controlling the line 13, while the piston 2 fulfills the task of a distributor for the fuel delivered by the pump during each delivery stroke. The two pistons, which are formed by a single part, then simultaneously perform a reciprocating movement and a rotary movement about their common axis, this rotary movement being imparted to them by means known per se, not shown. In addition, a certain number of delivery lines 4, z. B. four, each of which is provided with a check valve 5 and connected to a special injection nozzle. The piston 2 has in its upper section a groove 22 which has an axial direction and connects the pressure chamber of the pump to another delivery line during each delivery stroke of the piston 2 during a number of delivery strokes corresponding to the number of delivery lines 4. So that at the end of each suction stroke the pressure chamber of the pump can be filled with fuel arriving through the feed line 3, a groove 23 is provided in the side wall of the piston 2, which is connected to the pressure chamber of the pump through a channel 24. ⁶ p

So that the auxiliary piston 10 not only has the task of controlling the inlet to the auxiliary cylinder 11 Part, but also that of the slide controlling the channel 13, are four longitudinal grooves 25 in the side surface of the piston 10 is provided, their arrangement with respect to the inlet line 12 or better with respect to four inlet ducts 12 (see FIG. 2) and with respect to the end of the channel 13, with which one opens into the cylinder is selected so that the cylinder 11 emerges from the line 12 or the lines 12 can be filled throughout the retraction of the piston 10, wherein at the same time the line 13 is kept closed, while always one of these grooves 25 the connection between the interior of the cylinder 11 and the channel 13 establishes from an instant which is immediately before the point in time at which the check valve 20 is opened by the liquid is, which during the hanging or upward stroke of the piston 10 by this piston in the Channel 13 and under the auxiliary piston 7 is promoted, up to a point in time which immediately after is the moment at which the valve 20 is due to the cessation of the delivery of the liquid from the piston 10 into the channel 13 closes.

It should be noted that this arrangement of the grooves 25 has the additional advantage that the Liquid can enter the auxiliary cylinder 11 throughout the retraction of the pistons 2 and 10. Furthermore, the pressing of the movable assembly containing the pistons 10 and 2 is thereby applied facilitates the cam driving them, since the feed pressure on the piston 10 is a favorable one Exercise meaning directed force.

FIG. 3 shows the lower part of a pump, the design of which is somewhat different from that in FIGS. While in FIGS. 1 and 2 the same slots 25 provided in the auxiliary piston 10 simultaneously control the inlet line 12 of the auxiliary cylinder 11 and the channel 13, in FIG. 3 these two functions are separated from one another. The function of controlling the supply is fulfilled in Fig. 3 by the slots 25 α , which are made in the side surface of the auxiliary piston 11, while the function of opening the channel 13 is performed by slots 26 provided in the side wall of the piston. The operation of these two sets of grooves is the same as that of the single set of grooves 25 above.

Claims (6)

Patent claims ■ 1. Self-regulating fuel injection pump with a reciprocating motion in internal combustion engines, in which a reciprocating motion executes Piston is driven mechanically from the outside and hydraulically during its own with the output stroke of the pump coinciding with the output of a control element generated, which preferably has the shape of a piston valve and during at least part of the period between the start of the piston retraction and the start of its next decline during its own decline, which it is under the influence one z. B. executes a return force supplied by a return spring, liquid through a Throttle body drives, whereby a braking is exerted on it, whereby a check valve is switched on into the channel through which the fluid generating the inlet of the control element arrives, characterized in that a slide, which is positively driven by the internal combustion engine, is connected in series with the check valve (20), which is controlled in such a way that it opens the channel (13 ) opens shortly before the time at which the check valve normally opens, and this channel closes immediately after the time at which the check valve normally closes. 2. Pump according to claim 1, characterized in that the slide is a rotary valve. 3. Pump according to claim 1 and 2, characterized in that the channel (13) controlling Slide (10) through the main piston (2) of the pump or through one rigidly connected to it Part (10) is formed. 4. Pump according to claim 1 to 3, characterized in that the main piston (2) of the pump, in addition to its reciprocating movement, executes a rotary movement about its axis, which allows it to simultaneously act as a distributor for the fuel supplied by the pump and to fulfill the task of a slide for controlling the channel (13) through which the liquid reaches the regulating element (T) for generating the slope of the same. 5. Pump according to claim 1 to 4, characterized in that the liquid which the Control element (7) drives during the delivery stroke of the pump, in turn by a widened one Part (10) of the main piston (2) is promoted, this widened part in one Auxiliary cylinder (11) works and is firmly connected to the main piston axially and in rotation, wherein longitudinal grooves (25) are formed in the side surface of this widened part (10), which on the one hand the inlet into the auxiliary cylinder (11) control so that this is with the inlet pipe (12) in communication during at least approximately all of the return of the piston and, on the other hand, the control of the channel (13) cause which the liquid to the control member (7) to generate the hanging of the same feeds. 6. Pump according to claim 5, characterized in that the number of in the auxiliary cylinder opening inlet ducts (12) equal to the number of on the side surface of the widened part (10) of the main piston (2) provided grooves (25). Considered publications:
Austrian patent application A 6856/58 [published on January 15. 1960 (Patent No. 210,668)]; French patent specification No. 1157 404. 1 sheet of drawings © 309 670/95 8.63